Poor acceleration ONLY after warming up (2003 Maxima)
04-05-2009, 11:03 PM
#81
I might have an idea. It is out there, but it is an idea.
1.) How miles on your max?
2.) Does it consume any oil?
From what I hear VQ35's tend to burn oil like a 60's chevy once they get to about 100K. If yours is using up more than a quart of oil between oil changes (hopefully it is not, but I have heard of it happening on the vq35), it could be possible for that to damage or clog the cats. I have heard of oil burning being bad for the cats, and a plugged up cat might cause this. As someone mentioned earlier in the thread, they had this happen and it affected their performance more when it was hot.
Probably not the case, but just a theory........
1.) How miles on your max?
2.) Does it consume any oil?
From what I hear VQ35's tend to burn oil like a 60's chevy once they get to about 100K. If yours is using up more than a quart of oil between oil changes (hopefully it is not, but I have heard of it happening on the vq35), it could be possible for that to damage or clog the cats. I have heard of oil burning being bad for the cats, and a plugged up cat might cause this. As someone mentioned earlier in the thread, they had this happen and it affected their performance more when it was hot.
Probably not the case, but just a theory........
2) Maybe
Everytime I took my car in for service at a different place they would always claim "the last place you went to didn't add enough oil" until one day the dealer made that claim and I showed them that they were the ones that did the oil change then they magically pulled the most dumbest statement out of their butts that made me want to smack them: " Uhmm, according to Nissan it is normal for this engine to burn 1 quart every 1,000 miles " of course I could not question it since he would just come back with "I dunno, that's Nissan Corporate"
04-05-2009, 11:35 PM
#83
Your advice actually gave me more of a headache than my local stealership who told me there's nothing wrong with my car simply because there's no check engine light and it starts and moves.
I appreciate your input but unfortunately we're not Master Nissan Techs here so we have no idea what you're talking about,
* "Knock Sensor"? What the? Where is it?
* "Unplug connector for the KS"? What the heck is KS?
* Fold up resistor leads? Uhhh?
* "Tape" I know I'm not technically "aware" enough but taping stuff doesn't sound right...
I appreciate your input but unfortunately we're not Master Nissan Techs here so we have no idea what you're talking about,
* "Knock Sensor"? What the? Where is it?
* "Unplug connector for the KS"? What the heck is KS?
* Fold up resistor leads? Uhhh?
* "Tape" I know I'm not technically "aware" enough but taping stuff doesn't sound right...
A correctly functioning KS has a specific resistance value. I can't remember what it is, but I found it by doing a search. Go to radio shack, buy that resistor, fold up the leads so they're thicker and stay inside the KS connector tightly and secure it with a little tape. It'll mimic a working KS and your car should run normal. That will be plenty fine to test out and allow time to get another KS.
Nissan dealer techs are RETARDED. They might as well be working at billy bob's shop in BFE. The KS may not throw a code (it only does that when the signal is out of range) and it DOES NOT throw a CEL. The car runs fine when it's cold b/c it's not taking any sensors into account except MAF.
Last edited by Child_uv_KoRn; 04-05-2009 at 11:38 PM.
04-05-2009, 11:41 PM
#84
The knock sensor is between the V (the engine block shape - KS=knock sensor). The connector is near the side of the V on the drivers side. You can see the wire going into the middle of it. It's a pain in the *** to replace unless you have someone with small hands. I just relocated it b/c I couldn't get the bolt in the hole and eventually dropped the bolt in the middle of the block lol.
A correctly functioning KS has a specific resistance value. I can't remember what it is, but I found it by doing a search. Go to radio shack, buy that resistor, fold up the leads so they're thicker and stay inside the KS connector tightly and secure it with a little tape. It'll mimic a working KS and your car should run normal. That will be plenty fine to test out and allow time to get another KS.
Nissan dealer techs are RETARDED. They might as well be working at billy bob's shop in BFE. The KS may not throw a code (it only does that when the signal is out of range) and it DOES NOT throw a CEL. The car runs fine when it's cold b/c it's not taking any sensors into account except MAF.
A correctly functioning KS has a specific resistance value. I can't remember what it is, but I found it by doing a search. Go to radio shack, buy that resistor, fold up the leads so they're thicker and stay inside the KS connector tightly and secure it with a little tape. It'll mimic a working KS and your car should run normal. That will be plenty fine to test out and allow time to get another KS.
Nissan dealer techs are RETARDED. They might as well be working at billy bob's shop in BFE. The KS may not throw a code (it only does that when the signal is out of range) and it DOES NOT throw a CEL. The car runs fine when it's cold b/c it's not taking any sensors into account except MAF.
Your description of the KS location is very good but just wondering if you know of a picture out there of this part & location on the 2003 Maxima? Thanks.
04-05-2009, 11:43 PM
#85
BTW, make sure the resistor is 5% tolerance (gold band on it, read up on resistor color code if it doesn't say it on the packaging).
Last edited by Child_uv_KoRn; 04-05-2009 at 11:46 PM.
04-06-2009, 12:29 AM
#86
Google image search for a pic of a KS, but you can't miss it in the car. It's the only thing in the space between the V. You can see the wire going straight to it.
BTW, make sure the resistor is 5% tolerance (gold band on it, read up on resistor color code if it doesn't say it on the packaging).
BTW, make sure the resistor is 5% tolerance (gold band on it, read up on resistor color code if it doesn't say it on the packaging).
04-06-2009, 06:18 PM
#88
04-06-2009, 08:13 PM
#90
And for that much, I'd be frolicking in the junk yard and grab a few haha. Or just use the resistor permanently. That's what I should've done. I didn't need it always running 93.
Last edited by Child_uv_KoRn; 04-06-2009 at 08:24 PM.
04-06-2009, 10:20 PM
#92
Uh.... ebay. Just match up the part number. Should be at the most half that for OEM. I paid 90 for mine and I thought that was too high. Car manuf. sicken me with their ****.
And for that much, I'd be frolicking in the junk yard and grab a few haha. Or just use the resistor permanently. That's what I should've done. I didn't need it always running 93.
And for that much, I'd be frolicking in the junk yard and grab a few haha. Or just use the resistor permanently. That's what I should've done. I didn't need it always running 93.
04-07-2009, 04:52 PM
#94
I unplugged my o2 sensors and im running fine now... On the front of the engine behind the bumper there is 4 plugs.. I unplugged the first 2. Dont know why it helped but I keep power through all RPMS when warm now. 0.o Someone tell me if this is a bad idea. lol Seems good so far.
04-07-2009, 06:27 PM
#95
I unplugged my o2 sensors and im running fine now... On the front of the engine behind the bumper there is 4 plugs.. I unplugged the first 2. Dont know why it helped but I keep power through all RPMS when warm now. 0.o Someone tell me if this is a bad idea. lol Seems good so far.
04-07-2009, 07:02 PM
#96
ECUs are so complicated these days along with the stupid EPA making us pay hundreds for a stupid power robbing CAT. Apparently the EPA doesn't care about a poor person being broke because they spent $2,000 on CATs, they only care about saving the birds in 10,000 years and not even that they mostly do it for political reasons anyways.
Anyways, if for example his CAT is slightly screwed up and O2 sensors sense the CAT's short-comings and then calculates everything thereafter resulting in crappier WOT...and of course eventually the CAT may get even worse to the point where it clogs the car's breathing but at this point he may just have a slight problem and now the O2 sensors can't complain to the ECU & the WOT can be a rebel.
Anyways, if for example his CAT is slightly screwed up and O2 sensors sense the CAT's short-comings and then calculates everything thereafter resulting in crappier WOT...and of course eventually the CAT may get even worse to the point where it clogs the car's breathing but at this point he may just have a slight problem and now the O2 sensors can't complain to the ECU & the WOT can be a rebel.
04-07-2009, 09:12 PM
#97
ECUs are so complicated these days along with the stupid EPA making us pay hundreds for a stupid power robbing CAT. Apparently the EPA doesn't care about a poor person being broke because they spent $2,000 on CATs, they only care about saving the birds in 10,000 years and not even that they mostly do it for political reasons anyways.
Anyways, if for example his CAT is slightly screwed up and O2 sensors sense the CAT's short-comings and then calculates everything thereafter resulting in crappier WOT...and of course eventually the CAT may get even worse to the point where it clogs the car's breathing but at this point he may just have a slight problem and now the O2 sensors can't complain to the ECU & the WOT can be a rebel.
Anyways, if for example his CAT is slightly screwed up and O2 sensors sense the CAT's short-comings and then calculates everything thereafter resulting in crappier WOT...and of course eventually the CAT may get even worse to the point where it clogs the car's breathing but at this point he may just have a slight problem and now the O2 sensors can't complain to the ECU & the WOT can be a rebel.
Idk if his ECU is crazy or what, but I still think he should use the resistor to test the KS and plug the O2s back in. If I unplugged mine the car wouldn't even start.
04-07-2009, 11:24 PM
#98
UPDATE: I replaced my Injen CAI’s air filter.
UPDATE(2): Need help analyzing throttle body situation:
For the fun of it I also decided to take apart the entire Injen CAI and put it back together more neatly.
The following may or may not be the source of my lack of power problem depending on everyone’s much appreciated experienced and/or expert analysis:
I pushed the throttle linkage to open the throttle plate and I saw a coating of black oily film all over the inside wall of the throttle body, pretty much looked like everything behind the throttle plate was coated with oily film.
I ran my finger down the inside walls and from a small swipe got a good amount of thick seeming black disgusting oil.
Is it normal to have any coating of oil in there much less a complete coating of oil inside?
I claimed from the very beginning that I was hearing a reduced amount of “cool” noise coming from the Injen CAI when the problem starting happening…could this be because the throttle body is filled with oily puss and not functioning to FULL capacity?
Is this the source of my problems or is all of this normal and I should move on?
Thanks all for your help and tips you have provided me and others so far.
UPDATE(2): Need help analyzing throttle body situation:
For the fun of it I also decided to take apart the entire Injen CAI and put it back together more neatly.
The following may or may not be the source of my lack of power problem depending on everyone’s much appreciated experienced and/or expert analysis:
I pushed the throttle linkage to open the throttle plate and I saw a coating of black oily film all over the inside wall of the throttle body, pretty much looked like everything behind the throttle plate was coated with oily film.
I ran my finger down the inside walls and from a small swipe got a good amount of thick seeming black disgusting oil.
Is it normal to have any coating of oil in there much less a complete coating of oil inside?
I claimed from the very beginning that I was hearing a reduced amount of “cool” noise coming from the Injen CAI when the problem starting happening…could this be because the throttle body is filled with oily puss and not functioning to FULL capacity?
Is this the source of my problems or is all of this normal and I should move on?
Thanks all for your help and tips you have provided me and others so far.
Last edited by capframe; 04-07-2009 at 11:37 PM.
04-08-2009, 09:56 AM
#100
Ok, I have an idea before you buy any more parts. Pull the main cat and have it inspected.
On the 02/03 cars there are no sensors after the main cat so it could be bad without throwing a code since it's not monitered by the computer. You could actually pull the cat and the computer wouldn't know.
If the internals are bad it could flow fine when it's cold. As it gets hot the internal structure could expand and clog up.
The cat is easy to remove and you can even try driving it with the exhaust open to see if it's better. It'll be loud but you'll know if it made a difference and it won't cost you anything.
On the 02/03 cars there are no sensors after the main cat so it could be bad without throwing a code since it's not monitered by the computer. You could actually pull the cat and the computer wouldn't know.
If the internals are bad it could flow fine when it's cold. As it gets hot the internal structure could expand and clog up.
The cat is easy to remove and you can even try driving it with the exhaust open to see if it's better. It'll be loud but you'll know if it made a difference and it won't cost you anything.
04-08-2009, 10:01 AM
#101
Ok, I have an idea before you buy any more parts. Pull the main cat and have it inspected.
On the 02/03 cars there are no sensors after the main cat so it could be bad without throwing a code since it's not monitered by the computer. You could actually pull the cat and the computer wouldn't know.
If the internals are bad it could flow fine when it's cold. As it gets hot the internal structure could expand and clog up.
The cat is easy to remove and you can even try driving it with the exhaust open to see if it's better. It'll be loud but you'll know if it made a difference and it won't cost you anything.
On the 02/03 cars there are no sensors after the main cat so it could be bad without throwing a code since it's not monitered by the computer. You could actually pull the cat and the computer wouldn't know.
If the internals are bad it could flow fine when it's cold. As it gets hot the internal structure could expand and clog up.
The cat is easy to remove and you can even try driving it with the exhaust open to see if it's better. It'll be loud but you'll know if it made a difference and it won't cost you anything.
So, what about the throttle body, ignore that for now, what's up with all that oil?
Seems hard to take the cat out, is that also known as the " pre-cat "? is that the one that I can replace with " headers " if I wanted to?
Where exactly is this CAT anyways?
Also, if I replaced with headers would I pass CA Emission bull crap?
Thanks,
Last edited by capframe; 04-08-2009 at 10:04 AM.
04-08-2009, 02:19 PM
#102
It's possible the oil is a symptom of a bad cat causing too much back pressure. The oil alone shouldn't cause your symptoms. I'd look at the main cat first. You need to rule it out first and it won't cost much to play with.
DO NOT go messing with the throttle body on an 02/03 Maxima. The throttle body is computer controlled and easy to damage. Then you could be looking at a lot of money and a trip to the dealer.
The two precats are mounted to the exhaust manifolds. The exhaust passes through them before entering the actual exhaust system (the pipes). They're designed to handle the cat duties until the main cat reaches operating temp.
Headers remove the precats and let the system flow better. There are ways to pass emissions with them as long as you have the main cat in place. You really need to figure out this issue before changing anything else. If the precats are bad then headers may be something to look at. Look at the main cat first though.
The main cat is under the car just after the y-pipe. It's a short, fat, round tube shaped like a football. Removing it is just a matter of unbolting it. It's very simple. If you're not up to it a shop can pull it out in a matter of minutes and tell you if it's bad or not. You can get a universal replacement for not too much money.
DO NOT go messing with the throttle body on an 02/03 Maxima. The throttle body is computer controlled and easy to damage. Then you could be looking at a lot of money and a trip to the dealer.
The two precats are mounted to the exhaust manifolds. The exhaust passes through them before entering the actual exhaust system (the pipes). They're designed to handle the cat duties until the main cat reaches operating temp.
Headers remove the precats and let the system flow better. There are ways to pass emissions with them as long as you have the main cat in place. You really need to figure out this issue before changing anything else. If the precats are bad then headers may be something to look at. Look at the main cat first though.
The main cat is under the car just after the y-pipe. It's a short, fat, round tube shaped like a football. Removing it is just a matter of unbolting it. It's very simple. If you're not up to it a shop can pull it out in a matter of minutes and tell you if it's bad or not. You can get a universal replacement for not too much money.
04-08-2009, 02:50 PM
#103
Thank you very much Derrick2k2SE for your very helpful analysis, I learned a lot.
BTW, I live in California so the main CAT may be 5 times the price here but anyways, good advice that I'll take and report back.
Also, so you're basically saying that if it is the MAIN CAT that is the problem and I fix it, then I should just leave the throttle body the way it is, the oil won't do anything?
BTW, I live in California so the main CAT may be 5 times the price here
but anyways, good advice that I'll take and report back.Also, so you're basically saying that if it is the MAIN CAT that is the problem and I fix it, then I should just leave the throttle body the way it is, the oil won't do anything?
04-08-2009, 06:38 PM
#105
Thank you very much Derrick2k2SE for your very helpful analysis, I learned a lot.
BTW, I live in California so the main CAT may be 5 times the price here but anyways, good advice that I'll take and report back.
Also, so you're basically saying that if it is the MAIN CAT that is the problem and I fix it, then I should just leave the throttle body the way it is, the oil won't do anything?
BTW, I live in California so the main CAT may be 5 times the price here
but anyways, good advice that I'll take and report back.Also, so you're basically saying that if it is the MAIN CAT that is the problem and I fix it, then I should just leave the throttle body the way it is, the oil won't do anything?
The cat shouldn't be any more expensive. Just order it online.
Yeah, don't worry about the oil for now and don't screw with the throttle body.
04-08-2009, 07:59 PM
#107
I removed the intake tubing up to the throttle body to check for air leaks then reinstalled. That did not help so I went to the stealership with the sole complaint of the P0507 code, that I checked the intake tubing for air leaks and found none, so I needed a new ECM.
I got a call back saying I had additional codes, relating to the throttle position sensor. Bull@%$! leave the car alone, I'll be right there I said.
The stealership jacked up my throttle body and wanted $1,400 to install a new one. Screw them, I bought a used one off here for $400 and simply bolted it on without problems.
Two days later the stealership ran the idle air volume learn procedure using CONSULT II and asked for $40. You can run that procedure yourself without CONSULT II, but its rather complicated and difficult to nail the first dozen attempts or so.
04-08-2009, 08:35 PM
#108
Member
Join Date: Aug 2002
Posts: 251
04-09-2009, 06:28 AM
#109
What he needs to do is diagnose the problem and stop randomly throwing parts at it.
A mechanic can check the knock sensor with a scan tool and read it's output in real time. I really think a bad knock sensor would throw a code right away though.
04-09-2009, 09:51 AM
#110
Just to chime in on the 2002+ throttle body. I went to an independant auto repair shop who cleaned the throttle body which caused a code to be thrown for ICS (idle control system) RPM higher than expected. Clearing the ECM did not help. I bought a generic scan tool, verified the code was there and set out to repair it.
I removed the intake tubing up to the throttle body to check for air leaks then reinstalled. That did not help so I went to the stealership with the sole complaint of the P0507 code, that I checked the intake tubing for air leaks and found none, so I needed a new ECM.
I got a call back saying I had additional codes, relating to the throttle position sensor. Bull@%$! leave the car alone, I'll be right there I said.
The stealership jacked up my throttle body and wanted $1,400 to install a new one. Screw them, I bought a used one off here for $400 and simply bolted it on without problems.
Two days later the stealership ran the idle air volume learn procedure using CONSULT II and asked for $40. You can run that procedure yourself without CONSULT II, but its rather complicated and difficult to nail the first dozen attempts or so.
I removed the intake tubing up to the throttle body to check for air leaks then reinstalled. That did not help so I went to the stealership with the sole complaint of the P0507 code, that I checked the intake tubing for air leaks and found none, so I needed a new ECM.
I got a call back saying I had additional codes, relating to the throttle position sensor. Bull@%$! leave the car alone, I'll be right there I said.
The stealership jacked up my throttle body and wanted $1,400 to install a new one. Screw them, I bought a used one off here for $400 and simply bolted it on without problems.
Two days later the stealership ran the idle air volume learn procedure using CONSULT II and asked for $40. You can run that procedure yourself without CONSULT II, but its rather complicated and difficult to nail the first dozen attempts or so.
normally, it's not recomended to clean the throttle body.
for the throttle position, there is a recall for that I guess.
04-11-2009, 11:56 AM
#111
It's possible the oil is a symptom of a bad cat causing too much back pressure. The oil alone shouldn't cause your symptoms. I'd look at the main cat first. You need to rule it out first and it won't cost much to play with.
DO NOT go messing with the throttle body on an 02/03 Maxima. The throttle body is computer controlled and easy to damage. Then you could be looking at a lot of money and a trip to the dealer.
The two precats are mounted to the exhaust manifolds. The exhaust passes through them before entering the actual exhaust system (the pipes). They're designed to handle the cat duties until the main cat reaches operating temp.
Headers remove the precats and let the system flow better. There are ways to pass emissions with them as long as you have the main cat in place. You really need to figure out this issue before changing anything else. If the precats are bad then headers may be something to look at. Look at the main cat first though.
The main cat is under the car just after the y-pipe. It's a short, fat, round tube shaped like a football. Removing it is just a matter of unbolting it. It's very simple. If you're not up to it a shop can pull it out in a matter of minutes and tell you if it's bad or not. You can get a universal replacement for not too much money.
DO NOT go messing with the throttle body on an 02/03 Maxima. The throttle body is computer controlled and easy to damage. Then you could be looking at a lot of money and a trip to the dealer.
The two precats are mounted to the exhaust manifolds. The exhaust passes through them before entering the actual exhaust system (the pipes). They're designed to handle the cat duties until the main cat reaches operating temp.
Headers remove the precats and let the system flow better. There are ways to pass emissions with them as long as you have the main cat in place. You really need to figure out this issue before changing anything else. If the precats are bad then headers may be something to look at. Look at the main cat first though.
The main cat is under the car just after the y-pipe. It's a short, fat, round tube shaped like a football. Removing it is just a matter of unbolting it. It's very simple. If you're not up to it a shop can pull it out in a matter of minutes and tell you if it's bad or not. You can get a universal replacement for not too much money.
The exhaust guru @ the shop accelerated the car in neutral and said that the exhaust components such as CAT sound too good and the car revs too high and that if the restriction were that great to cause such a power loss it would be noticed on Neutral REVs, bla bla.
The engine guru @ the shop said he wanted 2 hours labor to fully " investigate issue ".
Right after he said that he held the brake pedal while accelerating and a rattling noise was heard that I've been hearing for the past year that I thought was a piece of metal banging around.
The engine guru labeled this noise as " pinging " and claimed it is " pinging REALLY bad "
The guru then claimed that he knows the Maximas are known for having knock sensors go out and that he wants to try replacing that first.
He wanted ~$200 for parts and ~$100 for labor so I halted everything till next time since he couldn't get the part anyways and also so I can get your guys' valuable advice.
When I got home I discovered my car had lost 1/2 quart of oil in the past 1,000 miles, I replaced the 1/2 quart and tried to duplicate claimed " pinging noise " but could not but that might be maybe because I wasn't doing the duplicating steps correctly and also because perhaps this crazy issue is so crazy it doesn't want to duplicate stuff when you want it to.
Should I listen to the guy and replace the Knock sensor?
Can I do it myself, easy?
or should I tell the guy NOT to F' with the knock sensor and instead just to pay him the money for diagnosis to test his claimed " guruness "
What's up with this oil loss anyways, could it have anything to do with the problem?
If I pay to have my knock sensor replaced, I'm no expert but it's hard for me to imagine that a knock sensor problem will burn 1/2 quart of oil every 1,000 miles?
Your advice on this update is greaty appreciated, thanks.
04-11-2009, 04:28 PM
#112
No, a KS won't burn oil. Exhaust restriction would or you just now have the infamous VQ lol. If you have been gunning it like crazy the past 1k mi, then that's where your oil loss probably came from.
I told you to use the damn resistor and put everything back the way it was. It is practically free. How many parts can you test for a 100% complete result for free? I believe the resistor you need is 470K, but my memory fails me and can't find it for the 5.5 gens (I think it's the same as 4th gen).
Now, if the test improves nothing, then I was wrong and feel free to tell me. But you can't keep doing quasi-tests and replacing parts ***** nilly (like people have said above).
I told you to use the damn resistor and put everything back the way it was. It is practically free. How many parts can you test for a 100% complete result for free? I believe the resistor you need is 470K, but my memory fails me and can't find it for the 5.5 gens (I think it's the same as 4th gen).
Now, if the test improves nothing, then I was wrong and feel free to tell me. But you can't keep doing quasi-tests and replacing parts ***** nilly (like people have said above).
Last edited by Child_uv_KoRn; 04-11-2009 at 04:30 PM.
04-11-2009, 04:29 PM
#113
The guru then claimed that he knows the Maximas are known for having knock sensors go out and that he wants to try replacing that first.
He wanted ~$200 for parts and ~$100 for labor so I halted everything till next time since he couldn't get the part anyways and also so I can get your guys' valuable advice.
He wanted ~$200 for parts and ~$100 for labor so I halted everything till next time since he couldn't get the part anyways and also so I can get your guys' valuable advice.
04-11-2009, 05:53 PM
#115
No, a KS won't burn oil. Exhaust restriction would or you just now have the infamous VQ lol. If you have been gunning it like crazy the past 1k mi, then that's where your oil loss probably came from.
I told you to use the damn resistor and put everything back the way it was. It is practically free. How many parts can you test for a 100% complete result for free? I believe the resistor you need is 470K, but my memory fails me and can't find it for the 5.5 gens (I think it's the same as 4th gen).
Now, if the test improves nothing, then I was wrong and feel free to tell me. But you can't keep doing quasi-tests and replacing parts ***** nilly (like people have said above).
I told you to use the damn resistor and put everything back the way it was. It is practically free. How many parts can you test for a 100% complete result for free? I believe the resistor you need is 470K, but my memory fails me and can't find it for the 5.5 gens (I think it's the same as 4th gen).
Now, if the test improves nothing, then I was wrong and feel free to tell me. But you can't keep doing quasi-tests and replacing parts ***** nilly (like people have said above).
I think if I understood what you're talking about and could put it into practice my car would of been fixed 8 months ago
04-11-2009, 06:05 PM
#117
I tried to record the rattling sound that the car technician claimed was "pinging" from the outside of the car but engine noise was too high and since I'm not a pro recorder with a pro recording device I decided it was best to record from inside with doors closed since rattling sound is kind of sharp and I figured it could make it in the recording.
To duplicate the sound, I held the brake while accelerating car to ~2,000RPM and if you can make it past the harsh sound engine makes while accelerating in-place/stopped, the rattling is actually very audible.
Is that timing chain rattle?
an exhaust manifold or cover rattle?
Or is that just a metal clamp loose around some engine parts banging around other metal parts?
OR Is that really pinging?
The tech. said it was horrible pinging but I don't trust anyone other than non-profit maxima.org nowadays
If it is in fact PINGING then is the techs. suggestion to replace the Knock Sensor a good idea? Isn't that kind of stupid since a new knock sensor will just detect the pinging better, it's not like a bad knock sensor CAUSES pinging, right?
http://www.pascalonline.net/nissan/2...xima_sound.mp4
To duplicate the sound, I held the brake while accelerating car to ~2,000RPM and if you can make it past the harsh sound engine makes while accelerating in-place/stopped, the rattling is actually very audible.
Is that timing chain rattle?
an exhaust manifold or cover rattle?
Or is that just a metal clamp loose around some engine parts banging around other metal parts?
OR Is that really pinging?
The tech. said it was horrible pinging but I don't trust anyone other than non-profit maxima.org nowadays
If it is in fact PINGING then is the techs. suggestion to replace the Knock Sensor a good idea? Isn't that kind of stupid since a new knock sensor will just detect the pinging better, it's not like a bad knock sensor CAUSES pinging, right?
http://www.pascalonline.net/nissan/2...xima_sound.mp4
Last edited by capframe; 04-11-2009 at 06:35 PM.
04-11-2009, 06:55 PM
#118
Member
Join Date: Aug 2002
Posts: 251
Absolutely. I would say, it doesn't sound like pinging to me (may be just me though?..). however in these cars the pinging is loud outside, but barely (if not at all) audible in the cabin.
04-11-2009, 07:11 PM
#119
The knock sensor listens for knocking or pinging. When it hears knocking it tells the computer. The computer then retards the timing until it stops. For better power and efficiency the timing should be advanced right up to the point before it knocks.
I think the computer would know the knock sensor was bad and retard the timing heavily. That would protect it from a dangerous running condition and cause a loss of power. My 95 had a bad knock sensor and gave me a code.
A shop with the right equipment can plug in and test the knock sensor in a matter of minutes. I wouldn't let anyone "test" it by charging $300 for a new one. Call a few shops and find one who can test it properly. Should cost you well under $100.
In my experience knocking and pinging happen under load. Try reving it in neutral to see if you can still hear the pinging. You could have also heard pieces of cat material bouncing around in the exhaust. That can sound a lot like pinging but will do it even when reving in neutral.
If you can get under the car try this high tech test. Hit the exhaust (on both sides of the cat) with a rubber hammer or piece of wood. Listen for pieces rattling around inside the pipes. If you hear crap rattling around in there you know you have a problem. If not you may still have a problem. This wont rule out a bad cat but can confirm one if it's bad enough.
I think the computer would know the knock sensor was bad and retard the timing heavily. That would protect it from a dangerous running condition and cause a loss of power. My 95 had a bad knock sensor and gave me a code.
A shop with the right equipment can plug in and test the knock sensor in a matter of minutes. I wouldn't let anyone "test" it by charging $300 for a new one. Call a few shops and find one who can test it properly. Should cost you well under $100.
In my experience knocking and pinging happen under load. Try reving it in neutral to see if you can still hear the pinging. You could have also heard pieces of cat material bouncing around in the exhaust. That can sound a lot like pinging but will do it even when reving in neutral.
If you can get under the car try this high tech test. Hit the exhaust (on both sides of the cat) with a rubber hammer or piece of wood. Listen for pieces rattling around inside the pipes. If you hear crap rattling around in there you know you have a problem. If not you may still have a problem. This wont rule out a bad cat but can confirm one if it's bad enough.
Last edited by Derrick2k2SE; 04-11-2009 at 07:13 PM.
04-11-2009, 07:16 PM
#120
^ My timing was retarded at -1....just had my timing advanced today to 17...runs smoother and better throttle response as expected but i still get the feeling like im not producing the power i should be....did an acceleration test and from 60-75 was equal to or slightly less then a 6th gen with intake...while i have a slightly more modded engine and both autos *note not racing just hard acceleration comparison