Techs, ever seen this(oil leak)?

[gtsiawd96]

Okay, Some may know, I'm an Audi tech been for almost 3 years now. I'm working on a 2005 A6 3.2l 41,000 miles at work, and have come across a problem I have never seen before. The car came in a couple months ago, leaking oil. Another tech diagnosed the rear timing chain covers where leaking oil. He removed the steel stamped covers, removed the old sealant and applied a new thicker bead of sealant and reinstalled the covers. Car returns 3 weeks later leaking oil again, I wasn't working on the car but I gave a quick look, and this time it didn't look like oil to me much lighter I said transmission fluid, there were drops of fluid coming off the bottom of the transmission bell housing and the oil pan where they met. And also fluid all over one of the transmission cooler lines witch sits directly under the bell housing/oil pan. Well, another tech installed an oil filter housing, thinking it was that, the filter housing sits behind the intake manifold on the top of the bell housing on top of the engine, the housing is made of composite and the oil filter is a cartridge and sometime can leak down the backside of the engine. Okay, well now this week the car returns, service manager gives me the car, wants it fixed right. lol.

Well like I had originally thought I was thinking the Torque converter seal, or the transmission cooler line was leaking since the fluid was very clean, oil is pitch black hasn't been changed in 6,000 miles. I removed the trans inspected the torque convertor seal it was dry alittle dampness but not the source of leak. So I narrowed it down to the transmission cooler line leaking. Reinstalled the 350lb transmission ugh. Replaced the transmission lines. Filled trans fluid, drove vehicle overnight, next morning Fluid Again. WTF!!

So I have come to find out today that the source of the clean fluid is actually 6,000 mile old motor oil. Where the transmission bolts to the engine, is actually the rear lower timing chain cover witch also houses the rear main seal, since the engine is chain driven it sits on the backside of the engine. The chain cover is cast aluminum and has machine surfaces that bolt to the aluminum block, it also bolts to the backside of the upper oil pan. There is a thin layer of sealant no gasket. This is the part I have never seen before, the tolerance is so tight and so small. That it is actually filtering the dirty black oil when leaking out of the lower timing chain cover, and its coming out clean. This boggled my mind today.

So tomorrow, I will be removing the transmission agiannnn to remove the rear timing chain cover, replace the sealant and various other small seals in the area.

Anybody else ever encounter this? I thought it kind of funny

[russiankid]

German engineering.

[pinacup7]

wow that sucks. Do you just get straight time for that, or you still making some loot? I'll do rear mains all day. 14 hours, done in 3.5

[blkZ06]

I use to be a Porsche tech so oil leaks were a daily occurrence, never had to chase one that much though, good find

[SovXietday]

So essentially the sealant around the cover was filtering the oil? Interesting. Good find reguardless.

[SoStock92]

I think that is the most ridiculous design by the way - timing chain in the back of the engine? I have to say I do not envy anyone with a VW or Audi. They seem to be rather ridiculous cars. The only thing worse seems to be old Saabs with the serpentine belts against the firewall..

[Elliott18t]

Originally Posted by SoStock92

I think that is the most ridiculous design by the way - timing chain in the back of the engine? I have to say I do not envy anyone with a VW or Audi. They seem to be rather ridiculous cars. The only thing worse seems to be old Saabs with the serpentine belts against the firewall..

it sucks. my old v8 has two distributers at the back of the engine on both sides pretty much against the firewall .

[gtsiawd96]

Yah, the sealant seems to be filtering, I'm not sure if its the pressure of two plates together, and the sealant. But it sucks, alot. As for getting paid, I've been in contact with are Technical Field Team witch are the guys we call when were not sure what to do, than they direct us. So I'm pretty sure this is still going to be flat rate time. 7.5 hours to R/I the trans. The cover is alot more involved so hopefully, i'll be make some hours on this train wreck.

In all honesty most of these Audi/VW are not the hard to work on. And most things are very easy, This is the first time I have ever had to remove a lower timing cover on a new model A6 and they are the majority of are work load. They designed the chain in the rear so they could move the engine forward and also to move front transmission diff. for better wieght distribution.

Some pics of the flange and rear timing chain set-up

[DocWalt]

I have a similar leak in that the oil is coming out filtered. My valve cover gaskets leak a bit and it ends up on the bottom of the transmission, clean. Really weird. I just figured I was crazy, but it's interesting to see it actually does happen.

Timing chain on the back? Weird... How do you adjust it when the time comes, or is it completely automatic?

[pinacup7]

That chain setup doesnt look to bad, but i'm sure it sucked getting to it. 7.5 isn't bad for a warranty trans.

[gtsiawd96]

No the chains really are not bad you can only see half of them though. lol. The two upper gears left and right the chains go up to the camshafts. That whole area was covered by one huge cover(the cause of the leak in question). That was a bitch to get off.

Doc, the adjustment of chains is done automatically by spring loaded ramps, the chains are lifetime. So no real adjustment is needed, unless something breaks or stretches.

[SovXietday]

Yup, so glad I work on Honda's.

[russiankid]

Originally Posted by SovXietday

Yup, so glad I work on Honda's.

Haha, no crazy covers with weird sealants.

[cyron]

Originally Posted by SovXietday

Yup, so glad I work on Honda's.

I have to vouch for gtsiawd96, Audi's are easy to work on, but you do have to work on them often. I've figured about 10k mi something big breaks, and you fix one thing and another thing breaks right away...
On my 1.8 it takes about 1.5hrs to do a timing belt from the time I take the bumper off till I put it back on. And I'm a hack.

One of my buddies just sold his A4 2.0t and bought a 330i. His wife called his A4 beepy because he'd fix something and a week later the idiot lights would go off again.

[gtsiawd96]

Originally Posted by cyron

I have to vouch for gtsiawd96, Audi's are easy to work on, but you do have to work on them often. I've figured about 10k mi something big breaks, and you fix one thing and another thing breaks right away...
On my 1.8 it takes about 1.5hrs to do a timing belt from the time I take the bumper off till I put it back on. And I'm a hack.

One of my buddies just sold his A4 2.0t and bought a 330i. His wife called his A4 beepy because he'd fix something and a week later the idiot lights would go off again.

Yah lol, I'm down to about a little more than hour on a 01-03 1.8t T-belt/water pump. Now the TT 1.8t...ugh(douche chills). I hate old TT's. Now the new 2.0t, are pretty stout little engine. We really haven't seen many problems, Couple sensors, and a crank vent valves.

[JimH]

Gotta love the 1.8T waterpump. Got thrown a few times on them plastic pieces of ****.

[Mitsu4g63t]

HA! The chain on the trans side is.... different. Things like this are the reason why I decline working on VW's and Audis when they come into work (I'm a Honda tech, at a HONDA dealer). So my Service Advisor gives them to the guy beside me who owns a Jetta :p

[DocWalt]

Originally Posted by gtsiawd96

No the chains really are not bad you can only see half of them though. lol. The two upper gears left and right the chains go up to the camshafts. That whole area was covered by one huge cover(the cause of the leak in question). That was a bitch to get off.

Doc, the adjustment of chains is done automatically by spring loaded ramps, the chains are lifetime. So no real adjustment is needed, unless something breaks or stretches.

Ok, I just know that on some cars, you need to adjust them sometimes (really high miles, or something else caused it to stretch or whatever)