fans running full speed after car warms up!
08-02-2017, 05:17 AM
#82
thanks for info, now I am worried, if they did a nissan thermostat...or not
for what it is...i don think i will worry too much, im at 217k miles here... hopefully just get a few more years out this thing...
i am going to ask what they used tho
for what it is...i don think i will worry too much, im at 217k miles here... hopefully just get a few more years out this thing...
i am going to ask what they used tho
08-02-2017, 05:54 AM
#83
per the mechanics words... an OEM equivalent.... so it's aftermarket... sigh...
now I know what to look for though, and i found a how to on how do do the thermostat....so yea...
$716 do to thermostat, two gaskets from hard line water outet pipe, and bleed, and fill coolant system
now I know what to look for though, and i found a how to on how do do the thermostat....so yea...
$716 do to thermostat, two gaskets from hard line water outet pipe, and bleed, and fill coolant system
08-03-2017, 04:31 AM
#86
ha... late nite comical post... =)
car feels great like nothing happened, driving, idling, temps, it was quite a scare with all of the possible potentials, i will always watch that temp gauge a little closer in any car now
i have a theory on the high price I paid to do this work as well, but... what can I do
car feels great like nothing happened, driving, idling, temps, it was quite a scare with all of the possible potentials, i will always watch that temp gauge a little closer in any car now
i have a theory on the high price I paid to do this work as well, but... what can I do
08-04-2017, 09:01 AM
#87
guys, when should the fans be running full blast?
i dont remember ever hearing the fans going nutz over all the years of ownership!
after all the fixes w my thermostat and water pipe gaskets and overheating,
i got home after a 30 miles drive, and i run econ air at 60deg on the ACC unit, and i park keep the engine on and the fans are blasting.
in hindsight remember the fans acting funny right before my thermostat took a crap, and they are acting the same after all the repairs....
today I also noticed the temp gauge move a lil bit on my 30 mile drive to work, and it was offputting, since as u know that temp gauge barely moves when things are right.
i dont remember ever hearing the fans going nutz over all the years of ownership!
after all the fixes w my thermostat and water pipe gaskets and overheating,
i got home after a 30 miles drive, and i run econ air at 60deg on the ACC unit, and i park keep the engine on and the fans are blasting.
in hindsight remember the fans acting funny right before my thermostat took a crap, and they are acting the same after all the repairs....
today I also noticed the temp gauge move a lil bit on my 30 mile drive to work, and it was offputting, since as u know that temp gauge barely moves when things are right.
08-04-2017, 08:57 PM
#88
There are different conditions for when the fans run in high speed. The main difference is a/c on or a/c off.
When running the a/c, the moment the a/c compressor starts running, the fans start running at low speed. For the next part of the description, the fans operate differently based on the pressure of the R134A refrigerant in the a/c system. And don't waste your breath asking me why, because I don't know.
If the refrigerant pressure is less than 229 psi, the fans will run at low speed until the coolant temperature in the engine reaches 203º F. Then the fans will run at high speed. Usually this will cool the engine coolant down and at approx 185 - 190º F the fans will drop back to low speed until the coolant temperature rises to 203º F again.
If the refrigerant pressure is more than 229 psi, the fans will run at low speed until the engine coolant temperature reaches 212º F combined with the car travelling at 50 mph or faster. Then the fans will run at high speed until either the car slows down or the engine coolant temperature drops below 212º F.
That's the theory of operation. Now we have to bring this ugly thing called reality into the discussion.
Personally, I think the louder noise has something to do with the parts the mechanic installed. There are replacement fans out there that are not 2 speed like the original Nissan fan. They are one speed - high. Coupled with the fact that they come with their own fan blades that have a different pitch than the Nissan fan blade and you have more noise. These single speed fans cost 33 to 50% cheaper than an OEM style dual speed fan. An Autozone dual speed OEM style fan motor is $60 and you re-use the original fan blade. A complete dual fan assembly (fans and shroud) with fan blades is $160. Elsewhere, a generic 12" single speed fan (with fan blade) costs around $22. A dual, single speed fan with shroud assembly can be gotten for $70 and up.
Another possibility that I think is less likely is the the mechanic installed 4th gen fans. 4th and 5th gen fans are the same exact fan motor, but Nissan wires the electrical plug on the fan differently. Same plug, though. The wiring difference causes a reversal of the high and low fan speeds.
When running the a/c, the moment the a/c compressor starts running, the fans start running at low speed. For the next part of the description, the fans operate differently based on the pressure of the R134A refrigerant in the a/c system. And don't waste your breath asking me why, because I don't know.
If the refrigerant pressure is less than 229 psi, the fans will run at low speed until the coolant temperature in the engine reaches 203º F. Then the fans will run at high speed. Usually this will cool the engine coolant down and at approx 185 - 190º F the fans will drop back to low speed until the coolant temperature rises to 203º F again.
If the refrigerant pressure is more than 229 psi, the fans will run at low speed until the engine coolant temperature reaches 212º F combined with the car travelling at 50 mph or faster. Then the fans will run at high speed until either the car slows down or the engine coolant temperature drops below 212º F.
That's the theory of operation. Now we have to bring this ugly thing called reality into the discussion.
Personally, I think the louder noise has something to do with the parts the mechanic installed. There are replacement fans out there that are not 2 speed like the original Nissan fan. They are one speed - high. Coupled with the fact that they come with their own fan blades that have a different pitch than the Nissan fan blade and you have more noise. These single speed fans cost 33 to 50% cheaper than an OEM style dual speed fan. An Autozone dual speed OEM style fan motor is $60 and you re-use the original fan blade. A complete dual fan assembly (fans and shroud) with fan blades is $160. Elsewhere, a generic 12" single speed fan (with fan blade) costs around $22. A dual, single speed fan with shroud assembly can be gotten for $70 and up.
Another possibility that I think is less likely is the the mechanic installed 4th gen fans. 4th and 5th gen fans are the same exact fan motor, but Nissan wires the electrical plug on the fan differently. Same plug, though. The wiring difference causes a reversal of the high and low fan speeds.
Last edited by DennisMik; 08-04-2017 at 09:00 PM.
08-05-2017, 09:43 AM
#89
Senior Member
Join Date: Sep 2012
Location: The Northeast
Posts: 681
I never hear the fans running when sitting inside the car. I was checking my ATF the other day and the fans were cycling on/off at full speed when parked after a highway drive. When first starting the car in the morning with the A/C already on, both fans run at low speed. This matches what Dennis said above.
08-07-2017, 06:00 AM
#90
here's another scenario from today - drove 30 miles 615 am to 655 am , temps were in mid 60s and light to medium raining entire drive - I run econ (no ac but ACC set on 60) to get the fresh and and cool air if its cool outside (kinda like riding a a motorcycle) and i pulled up to work put it in park, and the fans were blasting... again temps outside 65 degs, - is this a sign?
I can not recal ever hearing the fans running like this,
Dennis thanks for all the info, very very apprcatied. I will say this i have my original nissan fans on there they were not touched along w the replacement koyo radiator that was replaced around 2014 note we kept the fans and just replaced the rad itself. So this fan noise is a new thing from old parts or my new scenario from the overheating (which is now cured as far as I can tell )
Is it possible my 15 year old fans have lost that dual speed control? i noticed the fans blasting when idling and parking a few days before I overheated, but now hear them after the overheating repairs and no overheating.
Could i just be super sensitive now to these fans (i highly doubt that, its a noise that makes you wonder whats goin on, why are they blasting when they never made enough noise to even notice etc.)
Also i have run this econ ACC at 60 deg for years now and do not remember ever hearing my fans. I run ac when its really bad, and they day I over heated I was running AC when it did.
I can not recal ever hearing the fans running like this,
Dennis thanks for all the info, very very apprcatied. I will say this i have my original nissan fans on there they were not touched along w the replacement koyo radiator that was replaced around 2014 note we kept the fans and just replaced the rad itself. So this fan noise is a new thing from old parts or my new scenario from the overheating (which is now cured as far as I can tell )
Is it possible my 15 year old fans have lost that dual speed control? i noticed the fans blasting when idling and parking a few days before I overheated, but now hear them after the overheating repairs and no overheating.
Could i just be super sensitive now to these fans (i highly doubt that, its a noise that makes you wonder whats goin on, why are they blasting when they never made enough noise to even notice etc.)
Also i have run this econ ACC at 60 deg for years now and do not remember ever hearing my fans. I run ac when its really bad, and they day I over heated I was running AC when it did.
08-07-2017, 10:47 AM
#91
alright heres another scenario -
5-10 min errand run, 64 degress outside all day, didnt even turn on the acc and had the vents completely off the entire time, get the errand done, and start back up on return trip, at my next red light w no music on I can hear the fans humming (full blast) and engine temp gauge regular right below half way
What gives ? what does this mean , it is not normal to me at all.
5-10 min errand run, 64 degress outside all day, didnt even turn on the acc and had the vents completely off the entire time, get the errand done, and start back up on return trip, at my next red light w no music on I can hear the fans humming (full blast) and engine temp gauge regular right below half way
What gives ? what does this mean , it is not normal to me at all.
08-07-2017, 09:23 PM
#92
More theory of operation - Without the a/c being on, the fans will start running at low speed when the engine coolant temperature reaches 203º F. The fans will run at high speed when the coolant temperature reaches 212º F.
That's just 9º from when the fans will start running at low speed. You would not necessarily notice any difference on the temperature gauge. What you need to do is connect an OBD code reader that can report more info then just the check engine light codes. Among the additional info is the engine coolant temperature.
Assuming you will get a reading that is 212º or higher, this says the fans and their control circuit are working as they should. The cause of the high reading needs to be determined. There are 2 things that could cause this. A bad ECTS sending out an incorrect temperature reading to the ECU or it could be a thermostat that isn't working within specifications.
The ECTS is the easier of the 2 items to deal with. They cost approx $25 at the local parts store, $43 at the dealer and only take about 15 minutes to put in. The thermostat is more involved to replace, but based on what has been done to your car, I think this is the culprit.
That's just 9º from when the fans will start running at low speed. You would not necessarily notice any difference on the temperature gauge. What you need to do is connect an OBD code reader that can report more info then just the check engine light codes. Among the additional info is the engine coolant temperature.
Assuming you will get a reading that is 212º or higher, this says the fans and their control circuit are working as they should. The cause of the high reading needs to be determined. There are 2 things that could cause this. A bad ECTS sending out an incorrect temperature reading to the ECU or it could be a thermostat that isn't working within specifications.
The ECTS is the easier of the 2 items to deal with. They cost approx $25 at the local parts store, $43 at the dealer and only take about 15 minutes to put in. The thermostat is more involved to replace, but based on what has been done to your car, I think this is the culprit.
08-08-2017, 08:17 AM
#93
Senior Member
Thread Starter
Join Date: Feb 2009
Location: Columbia SC
Posts: 2,284
Are you guys checking to be sure that both fans are running at the same time, same speed? Also at low speed and high speed? My original problem was the water pump went bad on my car. Which caused the fans to run full blast for much longer than normal at idle. But both fans should run at low speed when the coolant is a certain temp even if the ac is off.
08-08-2017, 08:43 AM
#94
Maxinout brings up a point that I tend to forget about, at least this early in the diagnosing. The water pump. Leaking coolant is not the only way the water pump can go bad. If the antifreeze solution has depleted all the anti-corrosion chemicals, the impeller blades will corrode away and the coolant flow is slowly reduced to nothing. The only way to diagnose this is to remove the water pump and look at it.
Here is a photo of a corroded water pump, originally posted by nestor lugo:
Here is a photo of a corroded water pump, originally posted by nestor lugo:
08-09-2017, 06:39 AM
#96
More theory of operation - Without the a/c being on, the fans will start running at low speed when the engine coolant temperature reaches 203º F. The fans will run at high speed when the coolant temperature reaches 212º F.
That's just 9º from when the fans will start running at low speed. You would not necessarily notice any difference on the temperature gauge. What you need to do is connect an OBD code reader that can report more info then just the check engine light codes. Among the additional info is the engine coolant temperature.
Assuming you will get a reading that is 212º or higher, this says the fans and their control circuit are working as they should. The cause of the high reading needs to be determined. There are 2 things that could cause this. A bad ECTS sending out an incorrect temperature reading to the ECU or it could be a thermostat that isn't working within specifications.
The ECTS is the easier of the 2 items to deal with. They cost approx $25 at the local parts store, $43 at the dealer and only take about 15 minutes to put in. The thermostat is more involved to replace, but based on what has been done to your car, I think this is the culprit.
That's just 9º from when the fans will start running at low speed. You would not necessarily notice any difference on the temperature gauge. What you need to do is connect an OBD code reader that can report more info then just the check engine light codes. Among the additional info is the engine coolant temperature.
Assuming you will get a reading that is 212º or higher, this says the fans and their control circuit are working as they should. The cause of the high reading needs to be determined. There are 2 things that could cause this. A bad ECTS sending out an incorrect temperature reading to the ECU or it could be a thermostat that isn't working within specifications.
The ECTS is the easier of the 2 items to deal with. They cost approx $25 at the local parts store, $43 at the dealer and only take about 15 minutes to put in. The thermostat is more involved to replace, but based on what has been done to your car, I think this is the culprit.
08-09-2017, 08:19 AM
#98
sorry for hijack, its just too similar
If you rev the engine quickly with rad cap off, and water shoots out like a geyser (I've seen it squirt 6 ft just from starting it), then you know the pump is working.
Also, you can take the internals out of the old t-stat and run it wide open and you'll see the water flowing a lot through rad cap hole.
Water pump almost never fails except under extreme circumstances (only water corroding impeller to bits, ice, etc).
Also, you can take the internals out of the old t-stat and run it wide open and you'll see the water flowing a lot through rad cap hole.
Water pump almost never fails except under extreme circumstances (only water corroding impeller to bits, ice, etc).
after sitting for 5 plus hours, can I just take my rad cap off and start the car and rev the engine and see what happens? or do I have to be warmed up after a recent trip? i am gettin really freaked out over possible water pump failure.
I had overheating issues 2 weeks ago, i got it fixed w thermostat, and hard water line gaskets to the block, flushed and filled radiator, head gasket is fine. No overheating at all since, but ! my fans are acting crazy on 60 deg days and no ac or heat running !
the vid above is of my fans blasting during idling on the way to work after 15 miles on a mild 64 deg day no heat or acc or vents being used.
radiator replaced 3 years ago w koyo, but original fans,
car drives fine other wise like nothing is wrong.
08-09-2017, 08:24 PM
#99
I watched the video and I have never heard fans that sounded like that. It kind of sounds like the fan blade is rubbing on the shroud or something.
Since there are 2 fans, let's try to see if it is just one fan or both. Open the hood and go to the fuse box by the battery. Look at the cover and locate the RAD FAN 1 and RAD FAN 2 fuses. Fan 1 is the driver side and fan 2 is the passenger side. Start the engine and when the fans are making the noise, pull one of the fuses out. Note what happens with the noise - it stops, it diminishes or there is no change. Turn the engine off and reinstall the fuse. Start the engine and pull the other fuse out. Again, note what happens with the noise. Turn off the engine and reinstall the fuse. Did the noise seem to be connected with just one fan?
another check of the fans. With the engine off, spin the fan blade by hand. It should turn almost effortlessly and not make any noise. Now take hold of the tip of the fan blade. Try wiggling it front to back. There should be ZERO play in the fan blade.
Child_uv_KoRn suggested revving the engine with the radiator cap off. If you are going to do this, DO NOT take the radiator cap off while the engine is hot. The coolant is under pressure and almost boiling. It will spray all over you and everything else. Remove the radiator cap while the engine is cold and then start the engine and let it warm up.
When you start a cold engine, of course the coolant is also cold. As the engine warms up so does the coolant. The coolant expands when it warms up. With the radiator cap off, the coolant will overflow the radiator and come out the cap opening. This would normally go into the overflow tank if the radiator cap were on. The coolant will not come out with any kind of force, it just wells up and overflows. If there are air pockets in the engine, then the coolant will blow out in your face.
When the thermostat finally opens, you will be able to see the coolant flowing in the radiator if you look. With the thermostat open, if you rev the engine, the water pump will send a surge to the radiator and it will geyser out.
Since the engine is not overheating, I don't see any particular value in revving the engine with the radiator cap off. After watching your video, I think you will find that one of the fan motors has a lot of play in it when you wiggle the fan blades.
Since there are 2 fans, let's try to see if it is just one fan or both. Open the hood and go to the fuse box by the battery. Look at the cover and locate the RAD FAN 1 and RAD FAN 2 fuses. Fan 1 is the driver side and fan 2 is the passenger side. Start the engine and when the fans are making the noise, pull one of the fuses out. Note what happens with the noise - it stops, it diminishes or there is no change. Turn the engine off and reinstall the fuse. Start the engine and pull the other fuse out. Again, note what happens with the noise. Turn off the engine and reinstall the fuse. Did the noise seem to be connected with just one fan?
another check of the fans. With the engine off, spin the fan blade by hand. It should turn almost effortlessly and not make any noise. Now take hold of the tip of the fan blade. Try wiggling it front to back. There should be ZERO play in the fan blade.
Child_uv_KoRn suggested revving the engine with the radiator cap off. If you are going to do this, DO NOT take the radiator cap off while the engine is hot. The coolant is under pressure and almost boiling. It will spray all over you and everything else. Remove the radiator cap while the engine is cold and then start the engine and let it warm up.
When you start a cold engine, of course the coolant is also cold. As the engine warms up so does the coolant. The coolant expands when it warms up. With the radiator cap off, the coolant will overflow the radiator and come out the cap opening. This would normally go into the overflow tank if the radiator cap were on. The coolant will not come out with any kind of force, it just wells up and overflows. If there are air pockets in the engine, then the coolant will blow out in your face.
When the thermostat finally opens, you will be able to see the coolant flowing in the radiator if you look. With the thermostat open, if you rev the engine, the water pump will send a surge to the radiator and it will geyser out.
Since the engine is not overheating, I don't see any particular value in revving the engine with the radiator cap off. After watching your video, I think you will find that one of the fan motors has a lot of play in it when you wiggle the fan blades.
08-10-2017, 07:02 AM
#100
I watched the video and I have never heard fans that sounded like that. It kind of sounds like the fan blade is rubbing on the shroud or something.
Since there are 2 fans, let's try to see if it is just one fan or both. Open the hood and go to the fuse box by the battery. Look at the cover and locate the RAD FAN 1 and RAD FAN 2 fuses. Fan 1 is the driver side and fan 2 is the passenger side. Start the engine and when the fans are making the noise, pull one of the fuses out. Note what happens with the noise - it stops, it diminishes or there is no change. Turn the engine off and reinstall the fuse. Start the engine and pull the other fuse out. Again, note what happens with the noise. Turn off the engine and reinstall the fuse. Did the noise seem to be connected with just one fan?
another check of the fans. With the engine off, spin the fan blade by hand. It should turn almost effortlessly and not make any noise. Now take hold of the tip of the fan blade. Try wiggling it front to back. There should be ZERO play in the fan blade.
Child_uv_KoRn suggested revving the engine with the radiator cap off. If you are going to do this, DO NOT take the radiator cap off while the engine is hot. The coolant is under pressure and almost boiling. It will spray all over you and everything else. Remove the radiator cap while the engine is cold and then start the engine and let it warm up.
When you start a cold engine, of course the coolant is also cold. As the engine warms up so does the coolant. The coolant expands when it warms up. With the radiator cap off, the coolant will overflow the radiator and come out the cap opening. This would normally go into the overflow tank if the radiator cap were on. The coolant will not come out with any kind of force, it just wells up and overflows. If there are air pockets in the engine, then the coolant will blow out in your face.
When the thermostat finally opens, you will be able to see the coolant flowing in the radiator if you look. With the thermostat open, if you rev the engine, the water pump will send a surge to the radiator and it will geyser out.
Since the engine is not overheating, I don't see any particular value in revving the engine with the radiator cap off. After watching your video, I think you will find that one of the fan motors has a lot of play in it when you wiggle the fan blades.
Since there are 2 fans, let's try to see if it is just one fan or both. Open the hood and go to the fuse box by the battery. Look at the cover and locate the RAD FAN 1 and RAD FAN 2 fuses. Fan 1 is the driver side and fan 2 is the passenger side. Start the engine and when the fans are making the noise, pull one of the fuses out. Note what happens with the noise - it stops, it diminishes or there is no change. Turn the engine off and reinstall the fuse. Start the engine and pull the other fuse out. Again, note what happens with the noise. Turn off the engine and reinstall the fuse. Did the noise seem to be connected with just one fan?
another check of the fans. With the engine off, spin the fan blade by hand. It should turn almost effortlessly and not make any noise. Now take hold of the tip of the fan blade. Try wiggling it front to back. There should be ZERO play in the fan blade.
Child_uv_KoRn suggested revving the engine with the radiator cap off. If you are going to do this, DO NOT take the radiator cap off while the engine is hot. The coolant is under pressure and almost boiling. It will spray all over you and everything else. Remove the radiator cap while the engine is cold and then start the engine and let it warm up.
When you start a cold engine, of course the coolant is also cold. As the engine warms up so does the coolant. The coolant expands when it warms up. With the radiator cap off, the coolant will overflow the radiator and come out the cap opening. This would normally go into the overflow tank if the radiator cap were on. The coolant will not come out with any kind of force, it just wells up and overflows. If there are air pockets in the engine, then the coolant will blow out in your face.
When the thermostat finally opens, you will be able to see the coolant flowing in the radiator if you look. With the thermostat open, if you rev the engine, the water pump will send a surge to the radiator and it will geyser out.
Since the engine is not overheating, I don't see any particular value in revving the engine with the radiator cap off. After watching your video, I think you will find that one of the fan motors has a lot of play in it when you wiggle the fan blades.
apologize for freaking about water pumps. but it sounded similar to my scenario w the fans running a lot, but i am not overheating at all any more so i dont think its that anymore. Thanks !!guys.
08-28-2017, 12:50 PM
#101
ok guys i cant wait to try this, hopefully this week.
i will say this, i definately saw my temp gauge jump from solid standard mid point line up a full notch to the next line while idling at a red w acc econ 60 on, it dropped back down once i started moving though. and then on that trip i watched it like my heart rate on every red light and stop over 10 secs and nothing.
fans still loud as heck after warmed up too.
complete side story - car shut off on me twice while drving in 24 hours, both happened after rolling (preparing for red ahead) and then braking (looong story) but hopping it was just a beat up battery w a CCA reading 300 range (battery labeld 585) i bought a CCA600 new for $127 plus tax. sometimes simple answers and solutions are possible. ( i did the whole OEM CPS sensors already less than 2 years ago)
drove over 60 miles since battery and running errands and long trips and nothing yet.
i will say this, i definately saw my temp gauge jump from solid standard mid point line up a full notch to the next line while idling at a red w acc econ 60 on, it dropped back down once i started moving though. and then on that trip i watched it like my heart rate on every red light and stop over 10 secs and nothing.
fans still loud as heck after warmed up too.
complete side story - car shut off on me twice while drving in 24 hours, both happened after rolling (preparing for red ahead) and then braking (looong story) but hopping it was just a beat up battery w a CCA reading 300 range (battery labeld 585) i bought a CCA600 new for $127 plus tax. sometimes simple answers and solutions are possible. ( i did the whole OEM CPS sensors already less than 2 years ago)
drove over 60 miles since battery and running errands and long trips and nothing yet.
09-02-2017, 04:36 PM
#102
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Join Date: Feb 2009
Location: Columbia SC
Posts: 2,284
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