The other day i drove out to my buddies house which is about 45 min away. My car warmed up as usual between the C and H. when i got there i noticed my temp guage had dropped all the way to cold..? so i let my car sit for a minute and it rose back to normal again. could it be a bad thermostat?

 

it has been a few years since you posted this. Can you tell me what the issue turned out to be.


Thanks,


LP

 

lapusa, do you get a CEL or other malfunction lamp display? Is the temp dropping below the expected area or dropping completely as if NO temp is being reported? My A3 temp gauge works when it wants to.
My problem appears to be to not be the ECT sensor itself, as it has been replaced and the problem promptly returned. Can wiggle wires and hold my mouth just right and it starts working again briefly, but then stops reporting. Have checked with a code reader and the other Engine Coolant Temp sensor (I have found 2 on my A3) is sending proper or at least reasonable temp information to the ECU with or without the temp gauge displaying it.

 

Re: 2000 Audi A6 Quattro - how low is too low for coolant temp to go?


after our local shop replaced the defective coolant temperature sensor 5/20/2016, the indicator light has not come back since.

When driving after a cold start, it takes approximately 6-7 minutes for the cockpit coolant temperature gauge to begin moving upwards. Next, it takes another 3-4 minutes for the indicator to get to the center where it remains fairly consistently when driving.

Thanks for your response.


LP

 

My main question at this point is basically if anyone is familiar with 2000 Audi A6 Quattro specs as to how low the coolant temperature can go safely. Can there be long term issues to the engine?

When going downhill, the coolant went as low as 155 degrees F.

In my humble opinion, I would think it would be better to at times go below normal average [normal] operating temperature low vs. going too HOT in which case engine damage can occur when an engine overheats.

I don't find as much information if the opposite occurs at times which I would assume may result from a thermostat that may be beginning to stick in the open position.

I see one person posted that a significant number of OEM Audi/VW thermostats over time have a tendency to stick "open" and aftermarket thermostats have a historical tendency to stick "closed" which could be definitely damaging to the engine over time. I have no idea if there are any facts to back this statement up but it was posted and it looks as if several other Audi owners have thermostat related concerns so it is possible there could be a pattern.


LP

 

When I began troubleshooting mine with an ODB reader the coolant temp rarely got above 180 or 185. Don't really remember the low side temp from that time. That was some time ago and do still hook up and check/clear CEL codes from time to time. Last time I noticed the temp staying closer to 150 degrees and am suspecting the thermostat may be sticking.
I will be watching to see if anyone has an answer. It's basically summer here and I don't think I'm in a hurry to replace the thermostat. Should have paid the extra parts & labor when the timing belt was replaced!