Jetta Intercooler O-Ring blow out

My 2004 Jetta TDI recently starting having intermittent loss of Turbo and then it failed all together. The check engine light finally came on and threw codes P0101 and P0299.

P0101 is MAF
P0299 is Underboost

I did some looking around and found my lower duct on the intercooler is looking a little separated and the O-Ring is blown out.
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I read somewhere that around 130k miles these things do tend to get loose. The car has 135k miles on it.

My question is, would this be the main problem causing the MAF error and loss of Turbo? Could there be another underlying problem that caused this boost leak? I would hate to get this all replaced and fixed and find out we failed to address the real cause.

Thanks.
-Rich

Well the photo doesn't appear to have come through, but it is in my photos here on the forum:

fix it!!!! clear the codes and drive it. if there are any other problems they will be come evadent

my 0.02- yes, blown out sealing O-ring could be the likely culprit for causing underboost code and the symptoms you describe. However it looks in the photo, it will only get worse (separate more) when the turbo spools and tries to pressurize the system. Start with getting that joint addressed. Hopefully, that's all...

Disassemble, clean, and inspect the tabs on the metal collars of the hose. If the tabs have wear, it will pop apart again. Hose will need to be replaced (~$100).

If it is good, get a new O ring and put it back together.

Here is the O-ring:



3C0-145-117-F

I get them from 1stvwparts.com for about $3 each. There should be two on that joint, two on a similar coupler collar on the other side of the intercooler and one up on top next to the intake manifold. There is a smaller one on the turbocharger pipe and I think that may be part number 3C0-145-117, but you better verify that.

I think on the IC connection the 1-inch metal spacer has the nubs on it and not the IC hoses (they have the bail wire that engages the nubs), so you won't have to replace an expensive hose if the nubs that the bail wire holds are worn down. After you replace the O-rings you must make sure that the joint clicks together. Just pushing it together sometimes will not engage the nubs onto the bail clip and the connection will blow apart under boost.

--Nate

here is a picture of a BEW charge air system disasembeled
The two smaller seal rings for the turbo discharge pipe are part number 3C0145117
The five larger size seal rings are part number 3C0145117F

and assembled

Great picks Kato!

There isn't a "set" mileage for parts like that to wear. My car has 95000 miles and I have had to replace all the O rings and the upper pipe

Great, thanks! Unfortunately I am driving this thing 75 miles each way commuting right now and just don't have time to dig into this all myself (my weekends are tied up getting our house ready to sell) Got a trusted diesel guy 3 blocks from my office who just did the TB and water pump kit for me. All this information certainly helps me understand the issues and hopefully we can get her humming along again.

ecarnell said:

Great picks Kato!

Click to expand...

Absolutey! Thanks. Now I know I need TWO of the smaller O-rings too.

If you ever have a turbocharger failure where metal bits get into the intake tract, you'll have to remove all of the above pictured parts and the intake manifold and clean out with kerosene and blow dry with compressed air.

--Nate

Short story long: the mechanic said they did disconnect those hoses doing the TB so he took responsibility, tore it apart, cleaned it all up, replaced the O-Ring and put it all back together at no charge.

Too bad that repair lasted all of 50 miles before the coupling disconnected again, so I am assuming I have a worn hose. Being an engineer and believing that duct tape and bailing wire still have a useful place in today's society, I snapped it back together, put a SS hose clamp on there and it has been trouble free for another 200 miles now, so hoping that does the trick and I don't have to replace the hose.

Is that an aftermarket BEW intercooler? Why it is so small? My PD has got an IC which is the same size as radiator.

That is stock intercooler.

This should be a sticky