Running hot AND cold?
Thread Starter
Audiworld Junior Member
Joined: Mar 2003
Posts: 86
Likes: 0
Running hot AND cold?
My 2001 225 coupe is running well (about 85,000 kms), but recently I have noticed that on the highway on moderate days, the temp gauge can drop below vertical (90C) and then when idling at a light can go to the right of vertical, but stop short of the red zone.
VAG-COM shows nothing.
Is the thermostat dying? Any other thoughts?
Many thanks.
VAG-COM shows nothing.
Is the thermostat dying? Any other thoughts?
Many thanks.
AudiWorld Uber User
Joined: Dec 2000
Posts: 53,281
Likes: 2
Could be several things....
Fans, Water pump, Thermostat, Temp sensor.
There have been a lot of Fan and Fan control problems here recently.
Monitor the temps with the HVAC controls and see what the actual temps are:
Press [Recirc] and [Up arrow] buttons together. Use left 'temp' control
Dial to 49. Press [Recirc] button again to display value. On average, normal operating temp is around 90 (degress C)
To return to HVAC controls back to normal, press [Recirc] and [Up arrow]
buttons together.
Display should return back to temperature control/display.
There have been a lot of Fan and Fan control problems here recently.
Monitor the temps with the HVAC controls and see what the actual temps are:
Press [Recirc] and [Up arrow] buttons together. Use left 'temp' control
Dial to 49. Press [Recirc] button again to display value. On average, normal operating temp is around 90 (degress C)
To return to HVAC controls back to normal, press [Recirc] and [Up arrow]
buttons together.
Display should return back to temperature control/display.
AudiWorld Super User
Joined: Mar 2005
Posts: 11,616
Likes: 2
possible water pump shard jamming up thermostat
it is possible that a chunk of the plastic impeller from the water pump came off and jammed open the thermostat.
60k miles is the recommended interval to change out the timing belt (along with all other related components). Check to see if you have coolant pumping back into the reservoir at idle and while revving the engine. If no coolant is being pumped back in, you have a busted water pump. If you aren't overheating, then keep a close eye on the temp until 60k miles.
...also, use Vag Com to see if you simply don't have an engine coolant temp sensor going out- a common issue.
60k miles is the recommended interval to change out the timing belt (along with all other related components). Check to see if you have coolant pumping back into the reservoir at idle and while revving the engine. If no coolant is being pumped back in, you have a busted water pump. If you aren't overheating, then keep a close eye on the temp until 60k miles.
...also, use Vag Com to see if you simply don't have an engine coolant temp sensor going out- a common issue.
AudiWorld Super User
Joined: Nov 2003
Posts: 2,006
Likes: 0
Steve sez, "normal operating temp is around 90c" What do you estimate to be a safe "normal range?"
meaning, some here have cars that run cooler, others hotter. I understand that <90c is not good because the oil doesn't warm up enough to burn off water and other condensates. What's the high end of a safe "normal range?"
~john
~john
Trending Topics
AudiWorld Stories
Bringing Audi to Life for Audi Fans
10 Strangest Audi Designs That Actually Made Production
Joe Kucinski
2027 Audi Q7 and SQ7: Audi Upgraded EVERYTHING!
Michael S. Palmer
Audi Unveils Absurdly Cool New Supercar: 10 Things You Need to Know!
Verdad Gallardo
The Highs & Lows of Every Audi C-Class Generation
Joe Kucinski
Top 10 Most Expensive Audis Ever Sold on Bring-A-Trailer
Brett Foote
10 Audi Features & Options We Miss the Most!
Joe Kucinski
Audi Recreates Crazy-Looking Speed Record Breaker From 1935
Verdad Gallardo
Coachbuilder Recreates the 1995 Audi TTS Concept
Verdad Gallardo
Every Audi V10 Car Ranked!
Joe Kucinski
AudiWorld Super User
Joined: Nov 2003
Posts: 2,006
Likes: 0
My new t-stat equalizes to about 98~99c. Maybe it's time to redo the t-stat myself
the shop that put it in last winter claimed they used a Behr (same PN as our OEM unit) but I suspect it is sluggish in opening. Maybe it's time to get one from the stealership and see if I can replace it myself.
~john
~john