Intercooler Hose Leaking(sweating) Oil Near The Intercooler

Intercooler Hose Leaking(sweating) Oil, Near The Intercooler

The intercooler hose beside the intercooler itself, is leaking(looks more like sweating) oil, and collecting some crud in the process.
I don't like the idea of oil being in there to begin with, but I guess VW had to comply with emissions, hence the recirculation type of design for these gasses to be emitted, hence the oiling. My questions basically are, do I need to replace the hose because the seal is faulty at that joint? Or will even a new one, not be able to contain the oil at that low point of the plumbing?
I'm also worried that since oil is leaking from there, then that must mean that I'm leaking and loosing boost??
What do you guys think about this?

No Problem. Some sweating is normal and it is hard to lose a 'little' boost. The hoses generally pop off and you lose most of your boost if you have an actual problem.
A Vag-com or a scan-gauge II will read your boost.

Bill

My thinking here is, that if something as thick as oil can leak out, air, which obviously has smaller molecules, will surely be leaking out at significant quantities. Am I thinking right here?

I've read elsewhere http://forums.tdiclub.com/showthread.php?t=120711&highlight=intercooler+hose+leak that oil leaking is normal, but I can't accept this....I need some more feedback on this issue.

None of the connections are 100% air tight. Air pressure pushing oil past the o-rings is going to happen. The turbo is producing more than enough boost to overcome the losses. The pressure sensor is past these connections, at the back of the engine compartment, in the rigid pipe going to the intake.

You might replace the o-rings if they are the black ones with the green ones (3C0 145 117 F). You don't need to replace the entire hose. The oil is coming from the crankcase ventilation system.

oil is leaking from my hose, too, right at the bottom, next to the oil pan, where the hose hits its flat spot. when i did my tranny fluid change last weekend, i noticed oil on the hose, the oil pan and up and to the back of the oil pan. it is all wet but coagualted, making me think that the oil is leaking out of that bottom joint on the hose and blowing back with driving and coating the rest of the area. there is also a fair amount in the sound deadening material in the belly pan.

with all the talk of oil chain pump failures, i was going to go to the dealership -- since my car is still under warranty -- and get them to look it over and diagnose. but, if this is fairly normal, i might just save myself the headache b/c sitting around at the dealership, only to have them tell you that nothing is wrong, sucks.

by the way, car has almost 43k, seems to use around .5-1 liter of oil every 10k, and has no overt signs of an oil pump chain failure (that is, no new sounds i can detect, and runs just as rough at idle as it always has).

MOGolf said:

None of the connections are 100% air tight. Air pressure pushing oil past the o-rings is going to happen. The turbo is producing more than enough boost to overcome the losses. The pressure sensor is past these connections, at the back of the engine compartment, in the rigid pipe going to the intake.

You might replace the o-rings if they are the black ones with the green ones (3C0 145 117 F). You don't need to replace the entire hose. The oil is coming from the crankcase ventilation system.

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Thanks for the o-ring info. I might try to replace a couple, and see what happens....

So basically, what you guys are trying to say is, that too much oil has accumulated in there over time, and the only solution to this, is to change this emissions complying, crappy recirculatory design, with something like a Pro Vent? I've thought about the Pro Vent before, but living and driving the car in temperatures like -20C and below, I've have read from quite a few Passat TDI members, that the Pro Vent tends to freeze up, and basically render the car useless, until it's towed to the garage.

or, drive harder more often to blow the oil through so it is combusted in the engine?

vw4life said:

or, drive harder more often to blow the oil through so it is combusted in the engine?

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Negative. The car is WOT'd once a day by rule , in order to keep the VNT vanes moving nice and freely, and also the idea that it will just keep things cleaner. So scratch that one out

volkswagendude said:

I've read elsewhere http://forums.tdiclub.com/showthread.php?t=120711&highlight=intercooler+hose+leak that oil leaking is normal, but I can't accept this....I need some more feedback on this issue.

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It is completely normal. It's a VW, gotta love them for their quirks.

To rid yourself of the oil-in-the-intercooler problem, do what VW is too cheap to do. Install a crankcase vent filter. Racor is one mfr. The available CCV filters are made for diesel trucks, so you generally have to buy the smallest available and shoehorn it in. On my 2004 B5.5V TDI, I found space below the intake air filter housing and above the plastic wheel well liner. I installed a drain hose from the CCV vent filter housing, down to a point where I can see it when I am rotating the tires every 5000 miles. In that interval, I get almost a pint of gook out; a mix of oil & water. I sleep MUCH better knowing that stuff is not getting into my intake.

More importantly, that gook is not clogging my intake manifold and is not having to pass thru the turbo's blades.

since i'm under warranty, i took mine into the dealer today, just to make sure there wasn't oil coming from somewhere else, too. they basically take the hose off, cleaned it up and said monitor it. just what i expected.

DickSilver said:

To rid yourself of the oil-in-the-intercooler problem, do what VW is too cheap to do. Install a crankcase vent filter. Racor is one mfr. The available CCV filters are made for diesel trucks, so you generally have to buy the smallest available and shoehorn it in. On my 2004 B5.5V TDI, I found space below the intake air filter housing and above the plastic wheel well liner. I installed a drain hose from the CCV vent filter housing, down to a point where I can see it when I am rotating the tires every 5000 miles. In that interval, I get almost a pint of gook out; a mix of oil & water. I sleep MUCH better knowing that stuff is not getting into my intake.

More importantly, that gook is not clogging my intake manifold and is not having to pass thru the turbo's blades.

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I'm seriously considering this option.

I don't think that VW was too cheap however. I'm sure that passing the "green" requisites had something to do with not going the less troublesome route, no?

My one Passat has had this leaking since day one. The other did not have any noticeable leaking, until yesterday.

I did the 30,000 mile oil change and now both the lower left and right sides have leaking into the underbelly pan!

I know it is not enough to worry about, but I have to wonder why it has gotten worse all the sudden. None for 30K miles and then on both sides.

volkswagendude said:

I'm sure that passing the "green" requisites had something to do with not going the less troublesome route, no?

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I thought all the plumbing was to get the turbo-compressed air over to the intercooler and back? It's the location of the intercooler way off in the bottom front corner of the engine compartment that necessitates all the plumbing.

That doesn't have anything to do with "green" requirements as far as I know.

You should check out the all the additional componentry used by the new Mercedes Blue-Tech diesels: Urea injection, particulate filters and so on. Now those are clean compared to our Passat TDIs. They had a booth at the Toronto Auto show last week with all the components laid out in detail.

blaz said:

I thought all the plumbing was to get the turbo-compressed air over to the intercooler and back? It's the location of the intercooler way off in the bottom front corner of the engine compartment that necessitates all the plumbing.

That doesn't have anything to do with "green" requirements as far as I know.

You should check out the all the additional componentry used by the new Mercedes Blue-Tech diesels: Urea injection, particulate filters and so on. Now those are clean compared to our Passat TDIs. They had a booth at the Toronto Auto show last week with all the components laid out in detail.

Click to expand...

No..I was talking about people asking why VW didn't add something like a provent, or adding a CCV. This would surely prevent many of these little problems like oil gunk accumulation within. This is what I was referring to as the "less troublesome route", and having to pass emissions being the reason why they opted without.. That re explained, I still could be wrong with my assumption however.....

There is a CCV. What they don't have is a good oil vapor separator. Which does take up space.

It's alarming how much oil is in these plenums

I guess I hadn't thought much of putting an oil separator for the crankcase gases until I popped one of the o-rings. I'm getting quite a bit of oil seeping out of the plenum. Kinda eye-opening.

Car is still under warrantee, so I'll have the o-ring replaced but I guess I'll rethink and possibly get one of these racor/provent contraptions.

First time post from somebody who knows nothing about cars and engines. I googled VW Passat intercooler hose problem and found this thread. Some of the posts seem to have the same problem as me. My 55 Passat with 90,000 miles had a major service last November. The VW dealership replaced the o rings (hose seals). Then 2 months ago I could hear very loud hissing from the front left of my engine. Took the car to a highly recommended garage near my work and I was told I needed a new hose to the intercooler. The mechanic showed me the hose and explained the design was rubbish because it was a push fitting and he'd seen lots pop off, it was also a metal to plastic connection. He also commented on the amount of oil in that area of the engine. The hose was replaced and the car was fine until last week. My oil light came on, I topped up then noticed oil patches on my drive. Took it back to the same garage who did the hose. I'm now being told the new hose is coming away. Apparently the connections on the intercooler are worn and the intercooler needs replacing. He said he would try and fit some jubilee clips or something to hold the hose in place but isn't confident of success. Just wondering if anybody has any comments or proven solutions ?

You might need a new intercooler. Mine sprang a leak at the joint between the upper plastic part and the aluminum heat exchanger. I used UV fluorescent dye poured into the boost air hoses at the crankcase (valve cover) ventilation hose connection upstream from the turbo intake. Using a UV LED flashlight and a very dark room, belly pan off, you can look up from underneath the car at the back end of the intercooler. The dye was glowing distinctly, but you had to know where to look.

Thanks for your reply. Car was back in the garage yesterday. Good news, the technician ordered a new clip which only cost 70p. The clip needed to be heated and shaped to create a tighter fit for the hose. It seems to have worked but will keep an eye on it.

I just hit 130K kms on my Jetta. Noticed the same problem. My friend who has been working on TDI's for over 15 years said it's normal and surprised mine took so long to start. He suggested draining on a yearly basis.

I know this is a old thread but my 2011 jetta with 48k is leaking on the bottom drivers side as well and I took it off the clean it maybe it has some junk on it and now it sounds like im leaking boost. I can hear it hiss at low speed when i get into the throttle. any other fixes?