I know this might be a topic discussed many times but I can't use the search function and it bothers me that it happens so much. My girls 03 Maxima seems to knock at approx. 2000 RPM's. It's pretty loud and has been happening ever since I can remember first meeting her. I've tried different grades of gas. I've tried Fuel System Cleaner. I've tried different brands of gas. All the same. It stays the same even during winter.

I finally had a chance to talk to a tech or 2 at Nissan and apparently this is a very common complaint (I'm not sure if all 3.5 owners complain about it since just about every Nissan car has the 3.5 motor). He even said his own car does it and he told me the engine is knocking. I didn't know this because I had never knew what a knock sounded like (Heard a ping though on previous car!). I got the feeling that the techs I talked to sounded like they genuinely thought that it wasn't a problem and that it wouldn't harm the car. But I can't see why it happens and ihow it won't harm the car in the near future. She only has another 2 years on her engine warranty I think.

I kept asking him about why the knock sensor isn't coming into play and how exactly it doesn't harm the engine. I don't remember exactly what answer he gave me but I still don't feel comfortable. I've looked for TSB's or recalls and can't find anything. Help please?

 

Anybody?

 

Try a catch can.

 

I'm not sure if you have the same problem or not because my car is 5th generation, 2000 and yours is 5.5th.
Anyways, a year ago I had knocking almost all the time at ~1500-2000 RPM. I didn't have any SES, CEL lights on or trouble codes stored in ECU. Everything seemed to be fine except that knocking. I was told that it could be MAF sensor so I decided to replace it with a new one. It worked like a charm - car stopped knocking, was and still is running fine.
May be you have the same problem. Check you MAF.

 

Anyway to check if the MAF is bad? I have a Multimeter. Also, wasn't their something tricky with replacing the MAF? Can I just replace it like any other MAF or does the dealership need to do something. Also, if the MAF was bad, wouldn't the CEL go off? Don't get me wrong, I don't have much trust in OBDII but still.

 

There have been plenty of cases where the MAF goes bad and the SES light stays quiet. You can always try disconnecting the MAF sensor and seeing if the problem still exists (this WILL cause the SES light to come on, but an ECU reset will cure this after the sensor is plugged back in and there are no other existing problems).

As for the MAF sensor being tricky... not really. Only catch is if you don't want to spend the 500 bucks it costs for a 03 MAF sensor, you CAN get a 70 dollar 5th gen sensor and fabricate it to work on the 5.5 gen. There are a bunch of threads already posted about this.

As for the knock, I'm skeptical it's a normal thing. I've never had it on my 5.5 gen.

Here is a testimonail from another thread:
Also, before you decide to replace the MAF (as expensive as it is), take a look at this thread. A lot of people outline other problems they have experienced with faulty MAF sensors. See if the car has any of these as well, if it does not, the problem may NOT be the MAF.

http://forums.maxima.org/showthread.php?t=398513

 

Thank you for the link to the thread. I'll study it carefully. More and more this is pissing me off. I'm not sure whether the techs at the dealer are lying to try to get me away or what but it's beginning to infuriate me now.

To be honest, I've never driven another Maxima but her car seems to run fine. Smooth idle, responds well to throttle, feels powerful. It's just that damn, ticking noise (which I guess is knocking). Would a audio file help?

Are there any websites that can tell me if her car has any TSB's or recalls?

 

Got the same issue in my 02' Max. Guess I'll worry about it when the CEL comes on, or I got the cash to replace the MAF.

 

You should also consider ignition coils, I believe bad coils could cause misfiring and knocking.

 

does engine knock sound like something is knocking on the engine? why would you buy a car that already had a knocking engine?? i dont think its common among 3.5 engines.

 

how much is a factory MAF?

 

Depends on your year Maxima. One is Rape Me In The *** and the other is Rape Me In The *** No Lube!"

From what I've been reading, 2000-2001 is about $100 depending on who you get it from. The MAF's for 2002-2003 are about $500. Not sure why but I'm sure you can tell which one comes with No Lube.

 

And the 00/01 can be used in the 02/3. So either you like getting raped or you don't because you have a choice, and really don't have to if you're smart enough.

 

I too tried everything to stop this annoying knocking sound. I read several post regarding this issue. I flushed my radiator, had my fuel injectors cleaned, used only super unleaded, and changed my MAF. The MAF had the biggest impact, but the sound was still there under light acceleration (1800 rpms). Finally a mechanic suggested I change the spark plug to a cooler plug. This change almost completely eliminated the knocking sound. I hear on a few occasions but I have to be listening intently to notice it. I once again can enjoy my car

 

Quote from drivewire.com: "An open thermostat can result in low heater output, overheating and poor fuel economy. A thermostat that does not open or open all the way can cause knocking or pinging when accelerating and overheating."

 

True. Her car is most likely okay in that department. It heats up quite quickly and stays at perfect operating temperatures according to the needle. Vents blow out hot air too. Her mileage is bad but that seems to be a bit common around here. Her car is a GLE and is all leather with whatever trimmings. So I figured it might just be heavy compared to some other Maximas. Maybe.

UPDATE: She has been using BP 93 octane fuel ever since I told her to try to make a complete switch for a couple of months and it is getting much colder around here. Me and her have both noticed that the sound is almost gone. It could be either A) The Gas Brand B) The Cold Weather C) Both D) Coincidence. I'll check up on it and keep this thread updated.

 

well....
i have the same problem, i thought it wuz oil level to low but it wuznt.
a couple people on the org have had the same problem and told me it wuz the stock y pipe or sumthin to do with the exhaust.
i jacked up my car and had someone rev the engine up and sure enough, the sound was coming from the stock y pipe. at least i think so...
anyway for those who dont know what it sounds like ill post a video...

 

here is the noise...

http://media.putfile.com/Enginge-Knock

 

It had to be that she wouldn't put in a good brand 91+.

 

The knocking and pinging sound that I experience sounds nothing like the noise in the video. I can rev my car in neutral and not hear a rattling sound. It's only prevalent between 1700-2000 rpm range. It sounds more like marbles in the engine. But since I changed my spark plugs to a cooler plug, the sound is almost gone....

 

She used Shell 93 octane before the BP. If anything, if it was the Shell, I'd theorize that it was all those detergents they put in the Shell gas. A lot of people experience symptoms under that octane and brand. But like i said. I'll update every once in a while.

Same here. Sounds nothing like that.

 

Cheap gas? I cought my wife putting it in..she goes cheap every now and then

Install the catch can thing?

I installed it on my 03 and after a while it stopped it. Mine as the blowby issue that some of us just love to argue about. It seemed once the system was able to process the oil the pinging/knocking went away. My LS1 camaro has the same crap.

 

+1

Jibberish18,
Check out the inside of the intake manifold, you should find pools of oil. This is coming from your PCV. I added a catch-can to mine and cured about 90% of the low RPM ping.

 

Got pictures? Where did you pick up the components to build the catch can?

 

http://forums.maxima.org/showthread....2&page=3&pp=30

This may have what you need. I am using the small filter on both my cars and find it sufficient. Some argue its to small but it works for me.

 

I think I may take a crack at a catch can. Her car is still under warranty and it is sorta her car so I'm not sure I want to touch it yet but I may look into this. Not only would it be cool because it's my first catch can but because it would help her engine out too. Seems like Maximas spit more oil then your average bear hey Boo Boo?

 

was ur car low on oil sounds like a timing chain?

 

My 03 Max (60k miles) started pinging not too long after i put in a K&N filter. I pings with 93 octane as well. Its really loud sometimes and not as loud other times. After reading this link, I doubt the K&N filter is the cause: http://www.knfilters.com/MAF/massair.htm
I still plan on cleaning the MAF to see if it helps. If the MAF is bad, the SES light should go on.

 

i would check the oil level.. it sounds like your lifters.

 

im checking the tranny and am currently going through the same BS pm me if u want to discuss it further I could use some of your thoughts and maybe tell u what i have tried.

 

If the MAF goes bad, the SES is supposed to come on, right?