Need Help Figuring out the name of a part

[b7a408]

2008 A4 B7 2.0T

I am trying to figure out the name of #42 on the diagram. It has something to do with coolant. Thank you for the help in advance.

http://www.jimellisaudiparts.com/sho...rimLevel=19025

[JDillon15]

The thermostat?

[b7a408]

44 is thermostat, I believe

[JDillon15]

44 is thermostat, I believe

No, 42 is the thermostat.

check here.

part number: 06D121111G

I think 44 is a coolant flange.

[b7a408]

No, 42 is the thermostat.

check here.

part number: 06D121111G

I think 44 is a coolant flange.

I thought the Coolant Temperature Sensor went with the thermostat back of the engine and coolant flange was in the front. Might be reversed

[JDillon15]

I thought the Coolant Temperature Sensor went with the thermostat back of the engine and coolant flange was in the front. Might be reversed

Yeah, revered. The thermostat is on the side of the engine (driver's side) and the coolant flange is on the back with the CTS.

[b7a408]

thanks for the help

[JDillon15]

thanks for the help

No problem.

If you're looking to replace it, there's some pretty good DIYs on here. I've replaced mine. They're not very difficult.

[b7a408]

I've replaced the CTS o-ring before. Currently I have a small leak coming from the thermostat. I'll take a picture and post it. It looks likes a plastic piece of the small pipe cracked.

[ECS Tuning-Audi]

Definitely the thermostat.



Jason

[b7a408]

Sad thing is that the thermostat was replaced 3 years ago because it was failing. Here are two pics from this morning:

http://www.audizine.com/gallery/show...hermo2&cat=558

http://www.audizine.com/gallery/show...hermo1&cat=558

[JDillon15]

Sad thing is that the thermostat was replaced 3 years ago because it was failing. Here are two pics from this morning:

http://www.audizine.com/gallery/show...hermo2&cat=558

http://www.audizine.com/gallery/show...hermo1&cat=558

Yeah they are known to go bad. If you have a half-decent set of tools, I highly recommend replacing it yourself. You'll save yourself a ton of money and like I said above, it's really not difficult.

[b7a408]

Thanks again. I'll write an update once I decide what to do.

[b7a408]

Hello All,

It's been about a year since I noticed a small coolant leak forming under my car after driving it and letting it sit. During the past year, I bought two gallons of coolant and topped it off (50/50) every few weeks. Here we are a year later and I still can't find where the leak is coming from. I'm at 110,000 miles and it's time to replace the timing belt and water pump. I'd hate to have it done and not get the coolant leak fixed.

My thermostat works fine (was replaced 30K-40K miles ago). Everything in the front of the engine is dry and around the thermostat is also dry. Around the CTS in the back is also dry. I noticed a small puddle right behind the oil filter on the block. I took it to a mechanic to see if we can find the leak. He pressurized the coolant reservoir tank and lifted up the car but no leaking/dripping. I assume because the car was still hot. I'm attaching few photos of my situation. What is the metal box #43 in the diagram?

[aluthman]

#43 is the oil cooler. Check the coolant flange on the back of the head for leakage.

[4rings5stars]

O ring on the thermostat? Not replaced or not seated properly? Common issue
I did my t-stat 2 years ago and it's had a minor leak ever since. I put less than 5k/yr, so it's never been a priority for me.

[b7a408]

Thanks for the replies. I replaced the O ring on the CTS before and checked it this past weekend again. It's all dry. I think another member here suggested oil cooler gasket or coolant gasket...I'll have to look more into this.