Boost Leak 2007 2.0 TDI Jetta

[Cheezel]

Hello brains trust,

My Jetta has 152,000 kms on it, and has just developed an audible boost leak. Still goes fine, just hisses once the MAP gets over about 170 on my OBD reader. On the weekend, I pulled off the two hoses to the bottom of the intercooler and cleaned the O-rings and metal connectors. There was a fair bit of oily/dirty gunk on the outside of the intercooler connections. I've wiped this off and cleaned the plastic under engine tray to see about new gunk. Since cleaning these bits, it seems to happen even more. All the clips and connectors seemed to be in good condition. I cleaned the top accessible end of the pipe into the intake manifold also.

Is it likely to be leaking around the O rings? Do any of the hard plastic pipes crack? Is it likely to be the intercooler itself?

I get overboost limp if I bring on the boost at over 2000 rpm for an extended time, such as climbing hills at 110km/h on the freeway.

I suppose that at some stage, if the leak gets bad enough, the car won't drive real well?

Many thanks,

Richard

[Lucas_R]

It could be a hairline split in the hose or intercooler, a pin hole in the hose or intercooler, the o-rings worn etc etc - can you do a DIY smoke test to see if you can see where it is leaking?

If its leaking worse after removal and cleaning then its entirely possible that the oil and gunk was actually helping to block the leak somewhat and now that it has been cleaned, the leak is now worse.

[Lucas_R]

These might be the correct ones? FOR SKODA OCTAVIA VW GOLF V JETTA MK3 PASSAT 2.0 TDI TURBO INTERCOOLER HOSE PIPE | eBay

[feenix74]

We had a similar issue with our Mk 5 Golf 2.0 TDI last year. The rubber intercooler hose pipe (from Lucas_R's link) developed a split. Replaced and all good.

[Cheezel]

It would be nice if I could see where and which pipe was the problem. A smoke test sounds great, but how do you do that? And how to get it up to the pressure to get it leaking, or is it more that I can only hear it when the pressure is up?

Thanks for your input

[feenix74]

I do not think my mechanic needed smoke to see the problem with our one. I believe he could see the split with a torch. They had the car up on a hoist and one of the other mechanics rev the engine hard, it sounded like we had fitted a pop-off valve.

[Cheezel]

So, yesterday I was back under the car, and found that my leak was the elbow pipe directly off the turbo. I could just see the fibres poking out. So, I pulled it out, and 'reinforced' it with some duct tape, as I am having trouble finding one locally at a wreckers. I did ring VW to be told some $380!!

This morning's run to work had about 18km of no whoosh sound, but then I'm guessing the pressure made its way under some of the tape, and I now have a lovely squealing noise to go with the leak. I might need more tape! I didn't get any photo of the split or the tape, I was running out of time.

[feenix74]

Unfortunately, duct tape is not going to be able to hold against the pressure for extended periods.

See if you can get the part number from the dealer and then find the part on ebay for half the price.

[Cheezel]

I’ve got the part number in a photo, but I’m using the tape to extend the time before I find one other than from an overseas seller.

[feenix74]

Good plan, good luck I hope the tape holds out for you.

[Cheezel]

So, on Christmas Eve, I pulled the hose back off, and wrapped it with wire to keep it in the correct size and shape, put a bit of rubber glue in the crack, and then wrapped the lot with self fusing silicone tape with reasonable heat resistance. It looked the goods, and the car ran like a treat, until with four adults in it and the hills of the Central Coast NSW M1 on Christmas day with the A/C pumping, the silicone tape decided to start screaming too. Oh well. The car still ran well, just a bit more smoke than normal when the turbo kicks in.

When I pulled the hose back off again when we got back from Christmas, the silicone tape had ruptured across the back of the bend where it wasn't as thick, but the wire had held. The hose had split in a few more places as it needed to break between the wires. I took the hose off, as I'd been able to source another from Oli on here.

So, new hose, and the car is back to 'normal'. I don't think it's really possible to repair a pressure hose successfully, but the silicone tape did a great job, and maybe if I'd put some more layers directly on the pipe, and then wire wrapped the outside of the repair, then it may have lasted a bit longer. Anyway, all good for now.

[Tone13]

Hi there, I think my Skoda Octavia has the same issue. My high pitched leak noise is definitely coming from the rear of the engine bay, Do you remember the part number for this pipe?

Cheers

[Cheezel]

From a zoom in to the picture on the first page, I got VRT 1K0 145 790

I hope that helps. It’s the first hose off the turbo. You’re best to get under the car on ramps or a hoist and pull it off to check if yours is that hose. They come out fairly easily. The holding clips pop out with a screwdriver, then the pipe just slides out. Practice with the clip just at the intake on the front top of the engine to see how the clips work.

[Tone13]

From a zoom in to the picture on the first page, I got VRT 1K0 145 790

I hope that helps. It’s the first hose off the turbo. You’re best to get under the car on ramps or a hoist and pull it off to check if yours is that hose. They come out fairly easily. The holding clips pop out with a screwdriver, then the pipe just slides out. Practice with the clip just at the intake on the front top of the engine to see how the clips work.

Great, thanks for that. Will give it a go.