Engine Losing Coolant Rapidly

So yesterday I got the dash warning to check coolant levels. Sure enough the pressurized "death star" tank was empty. I filled it up to the line with coolant and had somewhere to drive...25 minutes later it was all gone again. So I started digging in.

I put the car up on some ramps and crawled underneath, pulled the plastic guard off the bottom of the engine, and there was coolant dripping from every bolt head down there all the way back to the rear tire on the frame rail on the passenger side.

The engine looked dry all over but obviously there's a leak somewhere. After a few hours of discovery, I THINK I have found the culprit...although I don't know for sure what it is, what it does, and how to get to it. There is a black tube behind the oil filter that sits between the filter housing and the block. The tube is metal and runs horizontal and parallel to the engine. From what I can see (which isn't much) the left side (passenger side) of that tube goes into a fitting and it appears loose. The water seems to be dripping from that area although I cannot see for sure where the water is originating. It may be on the bottom but at any rate it is in such a hard area to see that visibility is too limited.

I think my next steps are to pull the intercooler off and see if that opens things up a bit so I can get in there to that area. The problem with that is that I will have to break the coolant system which will take away my ability to test or locate the leak because I won't be able to pressurize the coolant system.

Has anyone ever fought this battle? Looking for some advice here.

Oil Filter Housing is cracked.
See this thread;

http://forums.tdiclub.com/showthread.php?t=482025&highlight=oil+filter+housing


Kinda of a pain to replace, best to remove the intercooler and cooling fans, new housing is $$$.

What’s a good place to buy replacement parts?


Sent from my iPhone using Tapatalk

Well...aftermarket it is!!


Sent from my iPhone using Tapatalk

What size are the bolts on the oil filter housing that has those triple square heads? A 6mm is too small and the 8mm won’t quite fit in and lock. Thinking I’ll need a 7mm maybe. Don’t have one so trying to measure twice and buy once!


Sent from my iPhone using Tapatalk

M8, had to tap in to fit all the way into the bolt head.

d2freeman said:

M8, had to tap in to fit all the way into the bolt head.

Click to expand...

Just to be clear these are the 12 point bolt heads?


Sent from my iPhone using Tapatalk

Yes, triple square. and I had to buy a set of long bits as my normal bits would not clear the housing. Below is like the ones I used
https://www.amazon.com/Neiko-10078A...point+bit+set&qid=1552861815&s=gateway&sr=8-1

Yep those look identical to the ones I have.
And this is one of the bolts circled in the picture.






Sent from my iPhone using Tapatalk

That does not look like the bolts, there are 4 total, 2 at the very bottom of the housing, and the one one the left is right above where the dipstick was mounted to the housing.
Check the bottom ones to see if it is the same size as that one as that looks much smaller that the ones on mine.

That’s the same ones. The locations match what you describe. Maybe the picture just makes them appear smaller.


Sent from my iPhone using Tapatalk

Also the torque specs are:
1. Tighten to 14 Nm, in a diagonal sequence.
2. Tighten an additional 90° (1/4) turn in a diagonal sequence.

Thanks for the information. I’ll give this another try tomorrow.


Sent from my iPhone using Tapatalk

Here is a link to a video of a 1.6 TDi looks like the same housing.
At about 8 min mark he says they are m8 12 point.


https://www.youtube.com/watch?v=t9UGMtfeA6c

Well it’s the oil filter housing alright. Attaching photos to show the failed area.








Sent from my iPhone using Tapatalk

Thanks for following up with your findings, and the image of the problem area on the part!