Running hot AND cold?
05-23-2007, 11:02 AM
#1
Audiworld Junior Member
Thread Starter
Join Date: Mar 2003
Posts: 86
Likes: 0
Received 0 Likes
on
0 Posts
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.
05-23-2007, 11:35 AM
#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.
05-23-2007, 12:32 PM
#3
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.
05-23-2007, 01:04 PM
#4
AudiWorld Super User
Join Date: Nov 2003
Posts: 2,006
Likes: 0
Received 0 Likes
on
0 Posts
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
05-23-2007, 02:05 PM
#10
AudiWorld Super User
Join Date: Nov 2003
Posts: 2,006
Likes: 0
Received 0 Likes
on
0 Posts
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