4.2quattrofan

Have hadA slow leak and have been adding coolant for a few weeks now all of a sudden cool it went really fast and now it looks like there's a leak at the middle rear top of the engine what could it be I can't tell with the fluid being blown around by driving

Matt94

I just had an issue with coolant leaking. I would check the fill tank. The clear plastic tank withe the blue cap. That's where my problem was and it's easy to take on/off to check. The top two plastic nipples where the rubber hoses go on were brittle and broke as I removed the hoses. The bottom had a leak as well. You can get a used oem tank on eBay fairly cheap. Easy fix if that's the problem.

MP4.2+6.0

Need t pull a few covers perhaps and look more. No single rifle shot suggestion, a least w/out more specificity of location. Certainly are water lines in back of motor area, plus lines that connect to heater. And coolant bottle as mentioned toward one side. And...

4.2quattrofan

Have pulled cover looks to be driver side center rear of engine throwing out coolant letting dry out now made it home. no over heating or raise in temp noted while driving. loos like right at the top almost dead center rear top of engine, hard to determine where after pulling up intake expansion tube, will look closer now that I am home. coolant bottle looks good to go

4.2quattrofan

looking for link of parts diagram for top rear coolant

Matt94

I would check the resovior. As you're driving/fans running it blows coolant everywhere. So start with the easiest stuff first and go from there.

Mister Bally

Link to good parts sites with diagrams in the Sticky at the top of the D3 thread.

Also note that the Harbor Freight coolant system pressure test kit, at $65.00 is a bargain and the adapter for VW/Audi works perfectly.

Bought it an used it troubleshoot a coolant system leak my son has been chasing in his TT for about a month. Found it and fixed it quickly with the pump and adapter cap.

Matt94

I couldn't really figure out my issue either until I removed the hoses and the resovoir. Once I did that and noticed how brittle it was I knew what the culprit was.

4.2quattrofan

Looks like the coolant sensor is (missing) an O ring is that possible? just deteriorated over time and has vanished?? is there an o ring seal on the temp sensor??

Matt94

I threw my old resovoir out this morning and today was trash pickup. I would imagine there has to be some kind of seal. If everything else on the resovoir is good and you'd like to keep it, you could get some jb weld rvt gasketmaker and try to seal it that way. You would need for it to be completely dry and about 24 hours for it cure without using it. Or you may be able to match up an oring but I'm not sure that'll be easy. I got one used for 40 shipped came with sensor cap and all. Let me double check my garage but I'm almost sure I threw mine out.