Coolant temperature fluctuates
4th Gear
Joined: Nov 2004
Posts: 4,153
From: Oswego, Illinois
RE: Coolant temperature fluctuates
ORIGINAL: TheJazz7
UPDATE on this issue...SAudi, I think you should've taken the bet.
I took my car to the dealership for some under-warrenty repair, and I mentioned my temperature fluctuations. I described the problem, told him I replaced the sensor, and then told him about the whole "ECT doesn't control the gauge temperature" theory.
His reply: "We checked the coolant system, and its working fine. Normal temperature and no codes. And the ECThas two leads coming off of it, andis connected to both theengine control moduleAND the temperature gauge in the dash. I'd recommend you stop listening to those guys on the car forums, most of them don't know what they're talking about."
[:@] I hate having a dealership service tech making me look dumb.
Anyways, this guy seems to disagree with AudiTech79...and it would be in his best interests to find a problem with my car, so he could charge me for it. PLUS the problem has gone away since I replaced the ECT. So based on those two factors, I'm gonna have to disagree with you on this one, AudiTech.
Just adding this in case someone is searching the archives in the future...and if you have conclusive proof to rebutt, by all means please share it.
Nothing but love...
UPDATE on this issue...SAudi, I think you should've taken the bet.
I took my car to the dealership for some under-warrenty repair, and I mentioned my temperature fluctuations. I described the problem, told him I replaced the sensor, and then told him about the whole "ECT doesn't control the gauge temperature" theory.
His reply: "We checked the coolant system, and its working fine. Normal temperature and no codes. And the ECThas two leads coming off of it, andis connected to both theengine control moduleAND the temperature gauge in the dash. I'd recommend you stop listening to those guys on the car forums, most of them don't know what they're talking about."
[:@] I hate having a dealership service tech making me look dumb.
Anyways, this guy seems to disagree with AudiTech79...and it would be in his best interests to find a problem with my car, so he could charge me for it. PLUS the problem has gone away since I replaced the ECT. So based on those two factors, I'm gonna have to disagree with you on this one, AudiTech.
Just adding this in case someone is searching the archives in the future...and if you have conclusive proof to rebutt, by all means please share it.
Nothing but love...
1st Gear
Joined: Oct 2008
Posts: 16
D@mn i should have but oh well, atleast i was able to help out a fellow audi driver, although i wish i left my old thermostat in, i just foudn out this winter that the new thermostat is set to open at a lower temp, so while my car does get hot, it just takes forever for the gauge to move to center and high heat never really feel high.
two words- heated seats...
1st Gear
Joined: Nov 2008
Posts: 23
From: New Hampshire
I am running into the same issue it seems; the EC gauge going to the middle then back down to almost C (0) . From what I see from this thread, try changing the EC sensor first?
I have a 2005 A4 1.8T...so that should be behind the engine with a black cap or blue?
I have a 2005 A4 1.8T...so that should be behind the engine with a black cap or blue?
1st Gear
Joined: Oct 2005
Posts: 13
Similar problem
I am having a similar problem. My problem is that it takes too long for the car to heat up and that the temp. goes from 90 to about 70 when I drive downhill or straight, which it didn't use to do.
The car is an Audi A4 2002 1.9 TDI
This is what I've found out:
When I start the car, the fan is running.
I then drove the car up to about 70C and the fan was still running.
Then got it to up to 90... Went through a hill so it dropped to 70... Checked the fan again, and it was still running.
So to me it seems that the fan is pretty much running all the time.
I'm not really car tech savvy, but that seems like a bad thermostat?
What controls if the fan is running or not? The thermostat?
I saw on another threat that someone wrote about "Radiator Fan Switch".
"yes i hope you find this to live up its title... if your fan runs all the time (even on startup from cold?) it is because your fan switch which is located in the radiator has shorted itself out. "Radiator Fan Switch" i guess it is - on my car it costed $46 thru auto zone. good luck"
So should I go for this rediotor fan switch or for the thermostat? Or does my car even have a radiator fan switch?
The car is an Audi A4 2002 1.9 TDI
This is what I've found out:
When I start the car, the fan is running.
I then drove the car up to about 70C and the fan was still running.
Then got it to up to 90... Went through a hill so it dropped to 70... Checked the fan again, and it was still running.
So to me it seems that the fan is pretty much running all the time.
I'm not really car tech savvy, but that seems like a bad thermostat?
What controls if the fan is running or not? The thermostat?
I saw on another threat that someone wrote about "Radiator Fan Switch".
"yes i hope you find this to live up its title... if your fan runs all the time (even on startup from cold?) it is because your fan switch which is located in the radiator has shorted itself out. "Radiator Fan Switch" i guess it is - on my car it costed $46 thru auto zone. good luck"
So should I go for this rediotor fan switch or for the thermostat? Or does my car even have a radiator fan switch?
1st Gear
Joined: May 2011
Posts: 4
digging up an old thread.
looks like i'm digging up a really old thread. but i have recently made the up grade to a newer audi having owned a 1988 audi 80 quattro and im having a hard time figuring out my 2000 a4 quattro 2.8.
the problem i'm having is after replacing radiator, timing belt, water pump and thermostat i'm still showing over heating issues. especially a really weird one where after the car has been sitting for 12+ hours my gauge reads right at running temperature starting the car even though i blows no hot air through the vents untill what normal warm up time would be and before i start the car the hoses and radiator are frigid cold. and usually after driving it will creep up to almost over heating even though i know its not. im at a loss for words. any advice for a young kid that misses his simplistic older audi at times?
the problem i'm having is after replacing radiator, timing belt, water pump and thermostat i'm still showing over heating issues. especially a really weird one where after the car has been sitting for 12+ hours my gauge reads right at running temperature starting the car even though i blows no hot air through the vents untill what normal warm up time would be and before i start the car the hoses and radiator are frigid cold. and usually after driving it will creep up to almost over heating even though i know its not. im at a loss for words. any advice for a young kid that misses his simplistic older audi at times?
1st Gear
Joined: Apr 2007
Posts: 102
From: SF Bay Area
Radiator Fan On at Cold Startup Keeps Coolant Cold
I am having a similar problem. My problem is that it takes too long for the car to heat up and that the temp. goes from 90 to about 70 when I drive downhill or straight, which it didn't use to do.
The car is an Audi A4 2002 1.9 TDI
This is what I've found out:
When I start the car, the fan is running.
I then drove the car up to about 70C and the fan was still running.
Then got it to up to 90... Went through a hill so it dropped to 70... Checked the fan again, and it was still running.
So to me it seems that the fan is pretty much running all the time.
I'm not really car tech savvy, but that seems like a bad thermostat?
What controls if the fan is running or not? The thermostat?
I saw on another threat that someone wrote about "Radiator Fan Switch".
"yes i hope you find this to live up its title... if your fan runs all the time (even on startup from cold?) it is because your fan switch which is located in the radiator has shorted itself out. "Radiator Fan Switch" i guess it is - on my car it costed $46 thru auto zone. good luck"
So should I go for this rediotor fan switch or for the thermostat? Or does my car even have a radiator fan switch?
The car is an Audi A4 2002 1.9 TDI
This is what I've found out:
When I start the car, the fan is running.
I then drove the car up to about 70C and the fan was still running.
Then got it to up to 90... Went through a hill so it dropped to 70... Checked the fan again, and it was still running.
So to me it seems that the fan is pretty much running all the time.
I'm not really car tech savvy, but that seems like a bad thermostat?
What controls if the fan is running or not? The thermostat?
I saw on another threat that someone wrote about "Radiator Fan Switch".
"yes i hope you find this to live up its title... if your fan runs all the time (even on startup from cold?) it is because your fan switch which is located in the radiator has shorted itself out. "Radiator Fan Switch" i guess it is - on my car it costed $46 thru auto zone. good luck"
So should I go for this rediotor fan switch or for the thermostat? Or does my car even have a radiator fan switch?
I am having this exact same issue with the radiator fan. So, was it the radiator fan switch or the T-Stat??
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