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Discussion Starter · #1 ·
Wat could be causing the dub to lose on oil on the driver side under the intake manifold 1. Oil Cooler 2. Something bigger ? If the oil cooler went would it just release oil everywhere ?
 

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There is a hard plastic pipe that makes a right angle and goes into the side of the engine. The pipe is for crankcase (oil) fumes and they rot out after several years.

Not likely to be a faulty oil cooler, but it could be a loose oil cooler. Only way to check it is to remove the oil filter and then check the tension on the nut which is on the pipe the filter screws on to. That nut is the only thing that holds cooler on, besides the filter when it is installed.
 

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If a loose oil cooler is causing a leak, will it leak down on to the filter or just drip off some other place? I ask because I'm also trying to track down a pesky oil leak on my 1.8T.
 

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If a loose oil cooler is causing a leak, will it leak down on to the filter or just srip off some other place? I ask because I'm also trying to track down a pesky oil leak on my 1.8T.

A loose cooler will almost certainly drip oil right down the filter and also the engine block.
 

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I had this same type of leak on my '99 1.8T and after I replaced the PCV, T fitting and hoses under there my leak stopped. They were all original and over 100k miles on them. There is a write up here that has the part numbers and how to.

Just my $.02
 

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Oil leak between Filter and Block

My wife took our '99 1.8T Passat sedan over to our local Valvoline Instant Oil on Friday on her way home and got the oil changed (5w30 Valvoline Maxlife full synthetic) . The next morning, when I started the car to let it warm up I heard a slurping sound under the hood. When I investigated, I noticed a major oil leak from around the filter.

Needless to say, I took it straight back to Valvoline to have it checked. They replaced the filter, topped off the fluid and showed me where the leak was coming from and sent me home. The house is less than 2 miles from Valvoline, yet by the time I got home the low oil pressure light was on. When I parked it, a huge puddle appeared on the driveway.

On my '99 1.8T there is some sort of auxiliary pump/bypass between the oil filter and the engine block. I *think* this is the bypass to the oil cooler and turbo. The coupling between this thing and the engine block is leaking like a sieve.

Does anyone know what this part is called? Is it something I can repair/replace myself or do I need to have it towed somewhere? If it is something I can fix, where can I get the part?

fpsm
 

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Is it a silver squarish block with rounded edges and two hoses going into it? If so, that's the oil cooler. Most online VW suppliers should have it. It may just have come loose.
 

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Yep. That's it. Thanks for the quick response.

Now, any suggestions on places to look for it? Or ideas on how difficult it will be to replace? From looking at the leak, it looks like it might be a bad gasket or seal between it and the block. Does that make any sense?

fpsm
 

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Seal could be bad, could just be loose. Replacing it should not be too hard as there is a fair amount of room down there.

Another leak spot in this general area is a bad oil pressure sensor which is on the back of the oil cooler/sandwich.
 

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Bad Oil pressure sensor:

-Leaks through internal defects, fills up boot around electrical cover, then drips off only when engine is on and oil is under pressure. Oil looks like it is all over side of engine block.

Bad Oil cooler gasket:

-Gasket/o-ring under the square Rube Goldburg looking silverish thing which is under the oil filter, the square part is the oil cooler and has two hoses coming out of it which are water coolant lines. These hoses not only help cool the oil, the reverse occurs when warming up the car, it helps warm up the oil quicker. You can check tightness by trying with your hand to turn the square oil cooler with the oil filter off (or if it moves with filter on thats not good), if it budges, go to a dealer and get a new oil cooler gasket, remover the cooler, replace the gasket/o ring and re-tighten the nut under the oil cooler. An oil leak here can leak down the oil filter and down the side of the block.

Bad PCV:

- This is the black cheap plastic pipe thing to the rear of the oil cooler. They fail, and leak oil down the side of the block.


I have had all three of these things leak. Additionally, a valve cover gasket went south it leaked at the back of the block. Since all parts replaced, engine is always dry. Just like my 1965 Mustang...

Oh, hint on working in that area, I used to go at it from underneath. Then one day I was changing radiator fluid and noted you could remove/move the radiator fluid reservoir located above the oil filter by removing three screws and lifting res out of the way, didn't need to remove any hoses, walla, lots of room to get at the filter from above.
 

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I need to address this very thing. I thought originally a bad seal on the filter but then I noticed the oil was from "above" the filter. I did buy an O-ring for the water cooler sandwich as a precaution since it's only $5. I'm hoping it's only the loose nut.
did the o-ring fix this??
i just got a 98 passat with a major oil leak like you describe.
is this the same as an "Oil cooler gasket"maybe i should post pictures.
I'll clean up the area and post a pic to make sure I'm on the right page.
 

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Crossed fingers and toes

Well, I ordered the new gasket from Autobarn in Mt. Pleasant, IL on saturday. It arrived last night. Hopefully I'll be able to figure out how to swap it tonight and the oil leak will be no more.
 

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If it wasn't leaking when you brought it in. And its leaking after.

It sure sounds like the quick lube guys tweaked your oil cooler and made it leak.

I'd have them pay to have it fixed at the stealer.
 

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I don't think it was them, I think it was either just age or the cold, but I can't prove it either way. It's my wife's car and she's the one that took it in.

Anyway, it was wet and nasty (and the garage is full of junk), so I didn't get to fix it last night. It looks like it will have to wait until after Christmas. *sigh*
 

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I'm right down the road from you, so let me know if you need a hand... With all of the "family functions" going on over the next few days, I may be looking for an excuse to get away for an hour or two. (Also, I've been thinking of installing oil pressure & temp gages in my car and this would be a good chance to get a closer look at the fittings & gaskets in that area)
 

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Discussion Starter · #18 ·
Update:
Turns out last time i changed the oil i couldnt get the filter off didnt feel like messing with it no biggie tho i did but a lil dent in it, tunrs out i guess from the warm engine and it being winter it just got the best of the filter and started to leak thanks tho for the hlep $6 fix
 
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