1.8T AMB Front main seal?

[GTA]

While doing a flush and fill of coolant and power steering fluid, I noticed this leak coming from the front crank. Obviously, there's nothing else it can be other than engine oil. But it's black and baked on the oil pan and hard enough that I would have to chip it off. Even brake cleaner doesn't seem to remove it. My engine oil doesn't look that black on the dipstick and I've never seen engine oil go that hard before.

Whadda ya think? Front main seal? Or could there be something else above it behind the plastic timing cover that can ooze this out?

Can this be caused by clogged up PVC system? My car had been running kinda rough on cold startup over the last few months but it never stalls and I haven't looked any deeper into this issue. Also no check engine light is lit and I haven't scanned it yet.

Sorry for so many dumb questions but I would like to know if they can be related and tied into the PVC system.

[Ozone510]

Def must be engine oil, could have hardened due to whatever contaminants it picked up from the environment. Like dirt, sand, anything that could change it's physical property. Looks like it's not a serious leak, but it will only get worse and it's good you caught it early. Try your best to clean it off and keep an eye on it until you replace it.

Sent from my SM-F711U using Audizine Forum mobile app

[Cybersombosis]

Check up above by the valve cover and cam seals. Oil will take a circuitous route down the front of the engine and it’s not alway apparent where it comes from so if you can see the leak higher up on the engine, it may not be the front main seal. Just have to get in there and clean it all. Only other way to confirm is to put it in service position and take it all apart which is not that hard, just time. About a couple hours of taking things apart. That way you can get in there and see everything once the harmonic balancer and timing cover are out of the way. Then take some parts cleaner and scrub away.

[GTA]

Yeah. I'm going to check to see if there's anything further up. I'm just hoping it's NOT the main seal. That'll be a royal PITA! I've done the TB and WP a few years back and I really don't want to repeat it

Thanks!

[codemode]

I have a leaking exhaust cam seal. You wouldn’t believe how big of a mess it made. But it’s not worth replacing it since you have to take half the car apart.

[EuroxS4]

Water pump.

[Puddin Tane]

Water pump.

Great call! The leak doesn't look like oil, does it? Oil would spread across the oil pan, and wouldn't dry into a crust like that

You've been reprieved, OP. What water pump did you use for that last TB job?

[GTA]

I used a quality kit w/ Hepu metal impeller WP, Continental TB, etc. Looking at the picture again, the light colored line in the center doesn't look like oil, does it? So the coolant must be picking up some oil on the way down as well. Kinda makes sense. I'll watch the coolant as well and see what's what.

Thanks Y'all.

Still, not a fun job.

[EuroxS4]

Great call! The leak doesn't look like oil, does it? Oil would spread across the oil pan, and wouldn't dry into a crust like that

You've been reprieved, OP. What water pump did you use for that last TB job?

I have seen such stains where the oring on the pump starts to disolve due to oil leaking near the water pump. This is what I would check first. You want to catch both oil leaks and coolant leak fast as overtime they will degrade the timing belt causing it to prematurely fail. Ive had numerous customers with this issue when timing was done with questionable parts or questionable skill set of technicians doing the job.

[Puddin Tane]

I have seen such stains where the oring on the pump starts to disolve due to oil leaking near the water pump...

Ruh roh! So head gasket or cracked head too. Guess I spoke too soon, OP.

[EuroxS4]

Ruh roh! So head gasket or cracked head too. Guess I spoke too soon, OP.

Cracked head would be only if its overheating at random cold starts. I have never seen a head gasket fail unless engine was badly overheated.

[GTA]

I have seen such stains where the oring on the pump starts to disolve due to oil leaking near the water pump. This is what I would check first. You want to catch both oil leaks and coolant leak fast as overtime they will degrade the timing belt causing it to prematurely fail.

Duly noted.

I took a peek down the rabbit hole with an endoscope and the TB doesn't seem to be stained in any way. However, I know what you're saying about the O-ring being affected as I see the coolant trail leading down:





I replaced the timing chain plastic pads a couple of years ago and when I looked this past weekend, I see oil flow down to the front of the block. I did tighten the valve cover gasket a bit more and cleaned around there. That could be the oil leak affecting the O-ring.

Thanks for the pointers Euro

[Puddin Tane]

Leaking intake cam seal underneath cam sensor, upper left on front of engine, is also in the exact right spot to do this.

[GTA]

Yes, It could be possible as well. I have to take a closer look in there when I have the time.

Thanks Puddin!

[EuroxS4]

Replace waterpump and call it a day.

[GTA]

So I'm seeing runny looking oil (not thick) on my garage floor and I had to add a bit of coolant to the reservoir. Not too bad yet but I plan to replace the TB/WP/tensioner with the same kit I used 8 years and about 75K Km ago when I did the TB job. Does this make sense or should I replace just the WP and O-ring?

I guess half the work is getting to the front of the block so it makes sense to replace everything not knowing how bad the TB is at this point.

There goes my Christmas holiday...

[Puddin Tane]

Does this make sense...

Since it's been that long and you're doing 90% of the job in any case, it's the only thing that makes sense. I don't know about that same kit though. I'd be disappointed with that WP.

[GTA]

I don't know about that same kit though. I'd be disappointed with that WP.

I believe the WP didn't fail. It's probably the WP O-ring that failed from the oil soak from my leaking valve cover gasket, at least that's my assumption. Any reason why I shouldn't buy the same kit PT?

[kwilson]

Any reason why I shouldn't buy the same kit PT?

That depends on what is in said "kit"

[GTA]

The kit I used 8 years ago was the following and it's still available to purchase today.

https://www.audizine.com/forum/showt...1#post11147142

[kwilson]

Well I wouldn't use that, but if you feel comfortable with the aftermarket water pump that didn't last and the older tensioner, it's your car.

[GTA]

Well I wouldn't use that, but if you feel comfortable with the aftermarket water pump that didn't last and the older tensioner, it's your car.

Oh? Can you at least elaborate as to why? I don't believe that the WP failed as it may be the O-ring seal deteriorating due to oil contamination. I won't know for sure until I have it opened up.

What would you suggest I get as a kit? Thanks for your input.

[kwilson]

There have been several recent threads here on this subject where we debated this topic. I prefer using genuine Audi water pumps, continental belts, and the newer Litens tensioner. Buy the parts separately instead of getting a kit so you know what you are getting. The Litens bracket isn't necessary. It just holds the roller, so I remove the hydraulic parts and refresh the roller. The following parts should run you under $300 US.

Timing Belt Contenental 06B109119A
Litens Tensioner Litens 06A109243A
Water Pump Genuine 06A121012G
Roller NTN/Febi 06B109244
Litens bracket 06A109181

[GTA]

Thanks kwilson. Maybe it's a good thing I haven't ordered any parts yet.

[GTA]

Another thing to mention is that the OE WP impeller is plastic instead of metal. Weren't there horror stories about the plastic deteriorating and pieces scattering all over the cooling system and rendering the pump useless?

For the metal impeller pumps, I have two choices that I can source locally: GRAF & HEPU. Any opinions for these brands? The one in my car now is a HEPU.

[kwilson]

I believe that the issues with the plastic impellers were back in the B5 days. The B6 uses a different material and has a better design than most aftermarket metal pumps.

[walky_talky20]

- HEPU pump with brass impeller is good stuff.
- Definitely go with the Litens unit and get rid of the hydro, if you are changing the belt.

/my opinion

[GTA]

- HEPU pump with brass impeller is good stuff.
- Definitely go with the Litens unit and get rid of the hydro, if you are changing the belt.

/my opinion

Thanks for the tidbit. The HEPU WP in my car now is 8 years old and I don't know if it sprung a leak by itself or the O-ring got contaminated with oil and degraded because of that. All I know is that I have a small leak on the front of the block, dribbling down and collecting motor oil residue with it and ends up on my garage floor. Not much but I don't like my car to leak anything.

And I've ordered the INA TB kit # ZD0546K from Rockauto yesterday. Definitely going with mech over hydraulic for the tensioner. Hopefully it'll save some time as well as sanity over the hydraulic tensioner. I remember it being pretty fiddly to install because of the spacing gap, etc.

Local prices for HEPU: CAD$80 + Tax & OE $145 + Tax. Eenie meenie. Haven't decided yet.

BTW, does anyone have experience with the GMB brand water pump? Rockauto has both a plastic impeller and a metal one.

UPDATE: After reading this thread: https://www.audizine.com/forum/showt...1#post11576227 I'm gonna go with OE Audi WP - plastic or not! It's not worth the hassle of tearing it apart again - especially in the winter months - for CAD$70 difference in price.

Plan to do it on the 23rd assuming I have all the parts in hand. Scored two sealed bottles (2 x 3.78L) of Audi/VW OE 50/50 coolant for $25 last week.

[Kevin C]

I have seen issues with the O-ring sealing when the surface of the block becomes pitted from corrosion. Clean the block to remove the pits or use a tiny shim behind the pump to change the location of the pump to a clean section of block. Based on the blocks I have seen it takes almost nothing to get past the pitting. You can also apply Loctite 518 to the face of the pump if the block is too trashed. the alternative is sand out the bore to get the pits out. That works as long as you still maintain good O ring compression. Sanding grit in the block can affect seal life. 18-20% O-ring compression is to the low side and a minimum.

[Gunnarrrrr]

Another thing to mention is that the OE WP impeller is plastic instead of metal. Weren't there horror stories about the plastic deteriorating and pieces scattering all over the cooling system and rendering the pump useless?

For the metal impeller pumps, I have two choices that I can source locally: GRAF & HEPU. Any opinions for these brands? The one in my car now is a HEPU.

horror stories of the plastic water pumps deteriorating are only because they were 10-15 year old pumps. People forget how old our cars are sometimes. personally I wouldn't trust even the metal pump to not have some kind of failure in 10 years. OEM plastic, or metal hepu/graf/geba. Just don't get a plastic aftermarket one. Either choice will be just as good, OEM probably being slightly better and more efficient. The only appeal of the metal pumps is that you're able to go cheap aftermarket with the peace of mind that the plastic won't disintegrate like a typical URO brand part or something. But if you get an OEM pump from a cheap source like oemvwshop or genuineaudiparts.com the price isn't much different. Whatever you go with, just make sure you swap it out again after 5-8 years to be safe

[GTA]

Kevin C: Duly noted and I'll look for any corrosion and definitely will clean the block and the around the O-ring seal on the block with plastic scrubbing pads. I'm assuming it didn't get as far a pitting the block as I only noticed it about in October. Before that, it was dry as I have my car up on a hoist a few times a year to do this and that and would've noticed the leak.

Gun: My car is nearing 300,000 Km so I don't expect too much more life out of it, though it still drives nice and the body is 99.95% rust free (I changed the passenger side front fender this past summer - typical rust on the bottom of the fender near the door) - even in the Canadian winters. If I can get another 100,000 Km and 8 years out of it, I'll be happy and won't have anything to complain about.

[EuroxS4]

I parted my avant out at 518k miles. I'd say you have plenty of life left. Also I only use factory water pumps. Never had one leak in between timing belt changes. Only times ive seen them leak is when the oring was cut when installing developing a small leak over time.

[GTA]

I parted my avant out at 518k miles. I'd say you have plenty of life left. Also I only use factory water pumps. Never had one leak in between timing belt changes. Only times ive seen them leak is when the oring was cut when installing developing a small leak over time.

A sign of confidence for sure. I'll be getting mine directly from VW this week.