# Thermostat???



## OUTTEA (Feb 12, 2011)

Hello TT folks;

Strange one here....

All signs pointed to a stuck open or weak thermostat. Ready 40 to 45 C max on sensor 49C. Barely warmth from heater.
Put in new BEHR PN 1.180.87.302 (fun stuff!). Old one was fully shut, possibly a weak one.
Now reading on 49C goes right to 60. I believe it should steady 90, right?
Did i get a defective thermostat? Could another sensor be causing an issue? Can this harm my car to run at lower temp?

Also, another strange thing happened after my venture under the hood. The BOSE goes into SAFE mode every time I start the car again. I enter the code in, all is fine. Until I park and get back in. Any ideas on that??

Also, sorry if this is posted in the wrong area, I haven't quite figured out where to post best at yet.

Thanks all!

Edward
2002 AUDI TT COUPE 1.8L


----------



## YELLOW_TT (Feb 25, 2004)

Welcome  You will get more help posting this in the mk1 section 
Dnot forget to join the TTOC www.ttoc.co.uk


----------



## Hoggy (May 8, 2002)

Hi Edward, Coolant should read 90 on gauge & on CC. Gauge is weighted & will read 90 when true temp is anywhere between 82 & 98 ish. If yours is 60 on CC after Thermostat change, then more than likely its the temp sensor, cheap & easy to replace. 
Click link & always best to get OEM sensor.

http://www.wak-tt.com/tempsensor/tempsensor.htm

Hoggy.


----------



## OUTTEA (Feb 12, 2011)

Thank you Hoggy and Yellow_TT!

I will join the www.ttoc.co.uk! thanks for that hookup!

Also, I do agree that the temp sensor is most likely malfunctioning after the test I performed today. 
I cranked the heater up to 84degrees F ( ~29 deg C). I only flowed air thru the dash, put in HVAC test thermometer in output vent and got a reading of 79 deg C ( 174 deg F) while the sensor "49C" was reading 60 Deg C.

My dash gage is not marked with numbers but only with tick marks. Now I know what they are to be.

Next Under The Hood (UTH) adventure will be to address the sensors mentioned by Hoggy.

I will post my issue with the SAFE problem in the MK1 section.

thank you for your help with the troubleshooting and the navigation of this site 

cheers


----------



## Hoggy (May 8, 2002)

Hi, Usually if Bose goes into Safe mode its usually because battery volts have dropped really low during start up, does the engine spin over quite slowly, if so probably battery on its last legs or a poor connection at battery. Check fuses/links on top of battery for corrosion/burning.
Hoggy


----------



## YELLOW_TT (Feb 25, 2004)

OUTTEA said:


> Thank you Hoggy and Yellow_TT!
> 
> I will join the http://www.ttoc.co.uk! thanks for that hookup!


Top man


----------



## T3RBO (Dec 9, 2003)

Welcome to the forum


----------



## OUTTEA (Feb 12, 2011)

Thank you all so much! I inspected the temperature sensor. There is a small coolant leak and signs of corrosion around it. 
Will be replacing in my next UTH (under the hood) venture. I will also take the advise to the new and OEM sensor.

Also, to follow up on the SAFE mode on the BOSE. Last year when my battery died, the BOSE never went into safe mode until I actually disconnected it. I was in a limp home mode at the time. However, I did inspect and clean the terminals. Still going into safe mode. Perhaps I hit a wire somewhere when I replaced the thermostat?

Thanks,
Ed


----------



## OUTTEA (Feb 12, 2011)

Turns out my battery was the culprit of the radio. On spot folks 
Went dead on me just a day later. Got it back on the road today.

Thanks!!!!


----------



## OUTTEA (Feb 12, 2011)

I replaced the coolant temperature sensor! WOW what a difference! the bad one had been adversely affecting fuel/air during cold start and I think it also effected the turbo boost!.

Dash Gage is of course reading perfect again!

Thanks all!


----------



## Hoggy (May 8, 2002)

Hi Edward, Excellent result, nice to get the feed back.
Hoggy.


----------



## rob2130 (Jan 7, 2012)

welcome to the forum


----------

