yvk_99

A month ago I had the infamous ChecK Engine Light On....with the help of someone I scanned it and came to know it was the Engine Coolant Temperature Sensor failure.

I went to a local shop and the guy had ordered the sensor which was a part white---part golden sensor....it was Bosch product....He replaced it and the light went off for about month.

Now I have the light on again, I scanned it and it does say Engine Coolant Temperature Sensor.

Now I am wondering whether the OEM Bosch part is the right part....????

Any suggestions.

98 Audi Quattro A6 wagon

twood

Mine went bad, too. It's my understanding that there are two different sensors for different model years (mine is a 96). Having the part ordered, but it may be the wrong part. Won't know until we get it. So I suppose it's possible that the wrong part was installed and that's why it failed again. I'll let you know what I find out when I get mine fixed.

Best regards,
Travis

yvk_99

After going thru several posts on the forum, I see that the ECT sensor is either blue or black in color.

I don't know if the one for 98 (late 97 production) A6 wagon can be white.

I also noticed on the internet that Oxygen temperature sensor supplied by Bosch is part white---part golden (metallic part).

So I wonder if he put in O2 sensor instead of engine coolant temp sensor.

will wait for your reply.

thnks

JPQuattro

I had that also with my 95 A6. It ended up being a bad thermostat. Is the car running cool?

yvk_99

It's really cold here in the NorthEast, like if I set the temp at 80 it would take a while....it does not start blowing hot air like other cars.

Also when the heat is on it does not blow hot air from the side and front and rear vents initially.

It starts with the vent or defroster near the front windshield.

Now how do I check if it is a thermostat problem.

The vag-tool from Ross-tech does not show this problem.

Last but not least how much does this thermostat cost parts and labor ???

Thnks

yvk_99

I turned on the car in 11 deg F ambient temp....let it run for around 20-25 min....the coolant temp guage reached 1/3rd mark....the heat was very low and only the vents facing up were blowing air....there was no air from the front vents facing the driver and the passenger. No air from the rear vents too.

After that I drove the car to fill gas about a mile....on my way back approx 2 miles the coolant temp guage was back to "c" from 1/3rd mark.

Is is the thermostat ????

I opened up the hood and the rubber pipes next to the coolant were pretty warm???

Any ideas anyone..////

yvk_99

BTW its a 98 wagon a6

Wagonmann

Temp gauge and MFD sensor are different. What is your temp gauge reading? Is the radiator fan switching on when it is overheating? What is the oil temp reading? Is your ignition switch working OK (do the turn signals work?). I have been down that hot/cold/temp sensor - road, and I think it is primarily related to rust, dirt, corrosion, and crap in the coolant passages.<ul><li><a href="https://forums.audiworld.com/a6100/msgs/7269.phtml">https://forums.audiworld.com/a6100/msgs/7269.phtml</a</li></ul>