took a road trip and engine temp dropped all the way to C...

**casawhites4** · 04-21-2008 11:20 AM

and then back to the middle again, then it dropped all the way to C again...kept on driving a little and jumped back up to the middle, know after driving back from rutgers..the needle is never in the middle its always a little towards the C or a whole line over...any ideas??

**AudiSportB5S4** · 04-21-2008 11:23 AM

lol i answered on AW, isnt that the Tstat stuck open?

**ubermidget** · 04-21-2008 11:31 AM

yeah my car used to do the same thing....thermostat

**casawhites4** · 04-21-2008 11:37 AM

lol, yeah ya did audisport...so is it something i should worry about it right now...or is it an easy fix...im assuming it is then

**gointoscott** · 04-21-2008 12:15 PM

Having the temperature gauge jump up and down can be caused by thermostat being stuck open or closed, normally when this happens the car will overheat.

Having your gauge jump between totally cold and half way is the temp sensor.
even if the thermostat was stuck all the way open there is no way the temp gauge would go completely back to cold. So this is why I would bet my money that it is the temp sensor. Usually it will throw a CEL (but not always) and should be triggered in Vag-com as a temp sensor not reading right.

These are known to go bad. They are cheap - 20 bucks and easy to replace. There is a writeup on audiworld, and may be one here on audizine too, just havnt looked. My gauge worked fine but was constantly getting a CEL, I finally vag'd it when I got a cable and found this to be the problem, replaced it on the street now is golden.

FYI if your car overheat's pull over and shut off immediately and do not drive!!! You can ruin your engine if you try and continue to drive it.

You probably know that, but just thought safe then sorry

**casawhites4** · 04-21-2008 12:32 PM

but i already swapped to the green temp sensor...and its only happened twice on the way up to rutgers which would be friday...not once since then...

**gointoscott** · 04-21-2008 12:39 PM

I C. Hmmmm well it could be the thermostat, but like I said it woudlnt go all the way to cold if the gauge was working correctly after the engine is warmed up.

How long ago did you switch the green temp sensor? maybe the new one was defective.

If it is the thermostat though, you have to tear the front of the engine appart to get to the thermostat. Not an easy job. So I would center on the temp sensor and make sure thats not the problem. Is it leaking any antifreeze?

**JDM EJ1 95** · 04-21-2008 12:40 PM

Originally Posted by gointoscott

Having the temperature gauge jump up and down can be caused by thermostat being stuck open or closed, normally when this happens the car will overheat.

Having your gauge jump between totally cold and half way is the temp sensor.
even if the thermostat was stuck all the way open there is no way the temp gauge would go completely back to cold. So this is why I would bet my money that it is the temp sensor. Usually it will throw a CEL (but not always) and should be triggered in Vag-com as a temp sensor not reading right.

These are known to go bad. They are cheap - 20 bucks and easy to replace. There is a writeup on audiworld, and may be one here on audizine too, just havnt looked. My gauge worked fine but was constantly getting a CEL, I finally vag'd it when I got a cable and found this to be the problem, replaced it on the street now is golden.

FYI if your car overheat's pull over and shut off immediately and do not drive!!! You can ruin your engine if you try and continue to drive it.

You probably know that, but just thought safe then sorry

this is not true... any car ive had with the TStat stuck open has dropped all the way down to cold unless its 80+deg outside.

the temp gauges in cars usually dont start reading till 100+ so anything below that will be on C..

**gointoscott** · 04-21-2008 01:01 PM

Originally Posted by JDM EJ1 95

this is not true... any car ive had with the TStat stuck open has dropped all the way down to cold unless its 80+deg outside.

the temp gauges in cars usually dont start reading till 100+ so anything below that will be on C..

This may be so, but I still find it hard to believe the temp of the engine would drop that low to have the temp gauge drop to Cold, unless it was really cold out. But I guess it could be possible.

**Matt@JHM** · 04-21-2008 01:37 PM

When my coolant temp sensor went out on my A4 it did not show a CEL - but it threw a code.

Check that before you dig out your thermostat.

**casawhites4** · 04-22-2008 12:08 PM

well i feel like if the sensor went out, wouldnt the gauge be stuck in the off position...like not readin at all...and how about...now..the gauge is just over to the cold section by one line...(hopefully you guys understand)