Cooling fans are staying on too long!

[Aronis]

Hello all

Need some help.

My car's cooling fans are staying on much longer than usual.

I noticed it tonight and it repeated after a short drive. It's 28 degrees here and I was not driving the car hard. Both the oil temp and water temp are in the normal range.

No check engine light.

Thank you,

Mike

[bruce]

Hello all

Need some help.

My car's cooling fans are staying on much longer than usual.

I noticed it tonight and it repeated after a short drive. It's 28 degrees here and I was not driving the car hard. Both the oil temp and water temp are in the normal range.

No check engine light.

Thank you,

Mike

CHeck this thread out:

http://rs6.com/forum/showthread.php?t=19869

[RS6NZ]

Hello all

Need some help.

My car's cooling fans are staying on much longer than usual.

I noticed it tonight and it repeated after a short drive. It's 28 degrees here and I was not driving the car hard. Both the oil temp and water temp are in the normal range.

No check engine light.

Thank you,

Mike

Very likely your thermostat. First place to start, anyway.

[Aronis]

Thanks. Had a temp sensor in rear of engine replace about 6 months ago.
Oh well I'll look into DIY.

Mike

[DHall1]

I doubt its the thermostat if the temp guage is reading normal.

Not the first place to look.

If thermostat stuck open in those temps....gauge would never reach normal.

If thermostat stuck closed....temp gauge would peg hot in 10 minutes no matter the temp.

Vag-com the engine temp readings. That will tell you what the coolant sensor is telling the ECU. If ok....then move on to the cooling fan relays

[s42ski]

I just went through this - car was running just a bit hot on the oil temp and the fans were running. Replaced thermostat fixed it - had the stealer do the timing belt at the same time and they charged me an arm and a leg for the parts.

If your car has the the extra radiators behind the intercoolers I think that and the oil coolers keep the engine from over heating with minimal coolant flow. My cars radiator was cool to the touch after driving it for 20 miles at 70 +.

[DHall1]

Good points.

Mike....run around town and get the temps up. Hook up your vag and sample the engine coolant temps. If temps look normal to just alittle warmer.....then run out and put your hand on the radiator tanks/core. The radiator should be warm/hot to the touch.

If not warm/hot to the touch.....it could be the thermostat.




I just went through this - car was running just a bit hot on the oil temp and the fans were running. Replaced thermostat fixed it - had the stealer do the timing belt at the same time and they charged me an arm and a leg for the parts.

If your car has the the extra radiators behind the intercoolers I think that and the oil coolers keep the engine from over heating with minimal coolant flow. My cars radiator was cool to the touch after driving it for 20 miles at 70 +.

[RS6NZ]

I doubt its the thermostat if the temp guage is reading normal.

Not the first place to look.

If thermostat stuck open in those temps....gauge would never reach normal.

If thermostat stuck closed....temp gauge would peg hot in 10 minutes no matter the temp.

Vag-com the engine temp readings. That will tell you what the coolant sensor is telling the ECU. If ok....then move on to the cooling fan relays

With the greatest respect mate, I beg to differ. Mine went a few months ago, and for 4 weeks and 1200 miles, the cooling fans starting early and staying on were the only symptom. I'm guessing the thermostat fails slowly and only partially opens for a while before fully failing.

Water temps remained normal for several weeks (in NZ summer @ 70-80F) after I started getting the cooling fan remaining on, but then water temp started to swing a bit more over time, eventually getting towards the red zone. I took it in to be looked at then and it was diagnosed as thermostat. Other other signs were of the oil temp rising above normal but only by a few degrees, hardly enough to notice. The thermostat was replaced (see below) and the problem fixed.

Be surprised for nasty surprise over cost if it is thermostat. The part is cheap, replacing it requires effectively same disassembly procedure as doing a timing belt replacement so you will probably ending up doing the belt and related bits as well.

[DHall1]

No problem. With the additional information added I would tend to agree.

Mike noted that his temp gauges were normal. In reality what you have noted is a rise in actual temps. Which was the thermostat sticking closed or restricted.

If you took the vagcom readings of the coolant sensors.....you would have noticed this overheating and then may have found the thermostat faulty. My direction would have the net same result. I also like s42ski's idea to place the hand on the radiator and end tanks.






With the greatest respect mate, I beg to differ. Mine went a few months ago, and for 4 weeks and 1200 miles, the cooling fans starting early and staying on were the only symptom. I'm guessing the thermostat fails slowly and only partially opens for a while before fully failing.

Water temps remained normal for several weeks (in NZ summer @ 70-80F) after I started getting the cooling fan remaining on, but then water temp started to swing a bit more over time, eventually getting towards the red zone. I took it in to be looked at then and it was diagnosed as thermostat. Other other signs were of the oil temp rising above normal but only by a few degrees, hardly enough to notice. The thermostat was replaced (see below) and the problem fixed.

Be surprised for nasty surprise over cost if it is thermostat. The part is cheap, replacing it requires effectively same disassembly procedure as doing a timing belt replacement so you will probably ending up doing the belt and related bits as well.

[Aronis]

Will take a closer look later.

Temporary "fix" I'll unplug the accessory fan. In winter they are not needed as main fan is spun by
engine directly.

Mike

[Aronis]

Spoke with the mechanic. He thinks may be fan control module. Will scan with Vagcom today.

Is covered by my warrentee. Zero deductable. Lol.

Mike

[Aronis]

Update:
I checked the VagCom

The Error Code is:

18613 - Performance Malfunction in Cooling System
P2181 - 008 - Implausible Signal

I cleared the code and the fan is back to normal. I am not sure how long this will hold, but at least I can keep intermittantly clearing the code until I can get the car in for service. The service person is working on the meaning of the code to determine what parts will be needed.

Mike

[Hy Octane]

Had same prob recently. Fans ran from startup to several mins afetr shut down.. Gauges all read normal. Replaced thermostat and all was well.. Then a few weeks later the temp gauge started to act up.. this threw a code and they replaced the sender unit. All ok.

[p3u]

I doubt its the thermostat if the temp guage is reading normal.

Not the first place to look.

If thermostat stuck open in those temps....gauge would never reach normal.

If thermostat stuck closed....temp gauge would peg hot in 10 minutes no matter the temp.

Vag-com the engine temp readings. That will tell you what the coolant sensor is telling the ECU. If ok....then move on to the cooling fan relays

Mine did the same, its normal to get a correct reading from the guage if the thermostat is open, just takes a bit longer to warm up, thats all.

[BenA]

My fan did the same thing-- especially in the cold, which made no sense - temp gauge never read hot. I've replaced the temp sensor twice in the past 3 months. I believe mine was accompanied by a temp sensor code and some kind of "running too rich" code and even a plug misfire code.

Running smooth now, but my power steering pump still sounds like a freaking bear when I start the car in the cold. It's well below zero here now with windchills in the -20 or so range.

[p3u]

Running smooth now, but my power steering pump still sounds like a freaking bear when I start the car in the cold. It's well below zero here now with windchills in the -20 or so range.

Ha, mine sounds like a wookie :)