Another Valve Cover Leak Thread

Hi All,

I have decided that the lower CCV delete isn't the best for oil leaks... My valve cover is leaking worse than ever despite my best efforts, and the blocked-off vent on the crank case is probably not helping. I will be replacing all the upper gaskets along with reinstalling the lower CCV vent tube and PCV.

This is my fourth valve cover gasket job I've done and it has leaked every single time. I have a NEW valve cover and all gaskets, but the valve cover leaks in the same place every time, at the cover/head junction behind the middle nut. Is there a proven way to banish these leaks once and for all?

Another forum thread mentioned using hylomar on the mating surfaces... I'm willing to try pretty much anything at this point because I have spent so much on gaskets for this car.

Thankfully, the engine isn't leaking from anywhere else...

On a ahu? Really?
You must be doing something wrong or something is causing you issues. I had the lower blocked off for 60k and running 30 to 32 psi. Never once saw the gasket I got from ID parts leak.
Have you replaced the standoffs or ensured the cover is not bent?

I think I made the mistake of nicking the sealing surface on the head with a razor blade at some point. Given that the leak is always in the same spot, that could be the culprit. I’ll smooth it down with some high grit sandpaper.. That doesn’t account for the bolt holes always springing a leak. I hate this design along with all the rest of us...

Does anyone have any suggestions on this? I have the same car and issue. I haven't dealt with it yet, but I have heard it is more than just replacing the gasket.

h.ubk

Just put a tiny dab of rtv on the spot you nicked
See how it works.

Are you replacing the upper and lower stud seals?

I’ve also installed washers on top of the cupped washers. This will allow a bit more tension at all metal to rubber points. You just need to ensure the washer’s inner ID is larger than the hex part of the double ended studs.

-Todd

h.ubk said:

Does anyone have any suggestions on this? I have the same car and issue. I haven't dealt with it yet, but I have heard it is more than just replacing the gasket.

h.ubk

Click to expand...

You need to use a little RTV at the corners of the cam caps along with new washer seals. Everything needs to be installed DRY. The cheapest I have found everything is from IDParts.com.

ToddA1 said:

Are you replacing the upper and lower stud seals?

I’ve also installed washers on top of the cupped washers. This will allow a bit more tension at all metal to rubber points. You just need to ensure the washer’s inner ID is larger than the hex part of the double ended studs.

-Todd

Click to expand...

I've done the same, the flat washer I've used has a large enough hole to fit over the hex and it helps to apply a little more pressure on the gasket.

I've also gotten some valve cover gaskets that I don't think were very good. I believe the brand was elring but I'll have to look to be sure. The packaging was a name in a red circle IIRC. I'll check and see what brand to be sure, I kept the gasket and package as a warning for the next order.

Steve

Steve Addy said:

I've done the same, the flat washer I've used has a large enough hole to fit over the hex and it helps to apply a little more pressure on the gasket.

I've also gotten some valve cover gaskets that I don't think were very good. I believe the brand was elring but I'll have to look to be sure. The packaging was a name in a red circle IIRC. I'll check and see what brand to be sure, I kept the gasket and package as a warning for the next order.

Steve

Click to expand...

I’m confused. Are we talking about putting a washer on the stud below the lower sealing washer so it pushes harder up into the valve cover? An extra washer under the upper nuts will do diddly for the same effective torque... at least by my limited understanding of physics.

FWIW, I have only used Elring gaskets thus far and all have leaked. Is the OEM different, like a Reinz?

garciapiano said:

I’m confused. Are we talking about putting a washer on the stud below the lower sealing washer so it pushes harder up into the valve cover? An extra washer under the upper nuts will do diddly for the same effective torque... at least by my limited understanding of physics.

FWIW, I have only used Elring gaskets thus far and all have leaked. Is the OEM different, like a Reinz?

Click to expand...

No, just the opposite, a washer on top of the cap just below the nut. That way there is slightly better pressure on the cap and rubber bits and it forces the VC to seal better.

Steve

I thought Elring aka Elring Klinger were an OE supplier. I’ve used these and other aftermarket brands and didn’t notice any difference.

It’s a poor design. I don’t reuse these or the actual gasket. Not worth my time or the headache to try and clean and reuse these, to end up with a leak. The washer trick cured my leaks.

I’ve used Hylomar, and while it works, it’s murder to clean off. Permatex used to sell Hylomar under their branding, but I was told it was too expensive to source and ship from the UK. They now market their own version, called Permashield. I’ve used it and it’s like Hylomar blue.

-Todd

Steve Addy said:

No, just the opposite, a washer on top of the cap just below the nut. That way there is slightly better pressure on the cap and rubber bits and it forces the VC to seal better.
Steve

Click to expand...

Do the stock nuts bottom out on the studs to bring the assembly to full torque? I am actually not sure. If so, then adding washers will work. Interesting, I’m guessing I’d need washers with at least a 10mm inner diameter to not contact the hex portion of the studs.

garciapiano said:

Do the stock nuts bottom out on the studs to bring the assembly to full torque? I am actually not sure. If so, then adding washers will work. Interesting, I’m guessing I’d need washers with at least a 10mm inner diameter to not contact the hex portion of the studs.

Click to expand...

Yes, that's part of the problem, the nuts bottom before putting sufficient pressure on the VC to seal. I believe the washers I used have at least 10mm center and are probably 2-3mm thick.

Steve

Those parts are like $10 on IDparts website. Just replace them

Mongler98 said:

Those parts are like $10 on IDparts website. Just replace them

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Not sure what parts you're talking about. I've replaced the rubber bits on the valve cover hold downs, they're available from VW, or at least they were last time I ordered them, but that was insufficient in solving the problem with the gasket, hence the reason for the washers.

Steve

The rubber cones on the head that the valve cover sits on. Reguardless, that's not where its leaking is it? It's where you damaged the mating surface right?.

Mongler98 said:

The rubber cones on the head that the valve cover sits on. Reguardless, that's not where its leaking is it? It's where you damaged the mating surface right?.

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It’s leaking from All three of the bolt holes and the perimeter of the valve cover.

You might want to check your compression. And that your puck on the top is free flowing. It sounds like you have a lot of CCV (crank case vent pressure)is there a mess of oil around the dip stick? Take the dip stick out and put a rag over it with a rubber band or ziptie. Get it warmed up on a short drive. If it's a normal amount, good. If its soaked, you have an issue that the gaskets are not going to handle

I wouldn’t be surprised if I have a lot of blow-by. This engine has 300K+ on it and some oil usage. Hence my thought about going back to the original CCV... I certainly feel like it leaks just about the same as before with the lower vent deleted. The original intent was to decrease the number of leak points with the delete but obviously this hasn’t solved the issue.. Let me try the gasket/washer method and if it doesn’t work I’ll try reinstalling the stock CCV...

No leaks at dipstick.

dont worry about the CCV bits from stock or not.
i ran a block off plate and a strait into the turbo inlet pipe with no puck.
30 PSI and lots of head lift but never saw a leak at all.
more to add to note, at that milage the valve guides get a lot of play in them and if you don't have a perfectly sealing valve, that can also cause a lot of pressure up at the valve cover. probably not your issue, just worth noting.
honestly, i would put a dab of RTV over the area on the outside of the cover and then put the nuts on. a thin washer can help, still, use some rtv to double down on it.

A couple updates - I pulled the valve cover and to my eye there were no nicks in the valve cover sealing surface. Cleaned everything thoroughly and applied some beads of RTV at the cam cap corners, and used 3/8" ID / 2.5mm thick washers over the cupped washers and under the nuts. Torqued to 10 Nm per the Bentley. No leaks thus far, although time will tell... I think the only thing I have to add is that when tightening the nuts you need to ensure the extra washers are perfectly centered so that they don't interfere with the hex portion of the studs.

Thank you for the help and tips.

great to heat.
OH btw a pro tip on gasket juice!
use a paint brush (plumbers flux brushes work great) this makes sure you use the bar minimum and prevents excess from entering the engine. ALSO apply it to the rubber gasket after cleaning it with some alcohol and rub a small film of oil on the engine parts its going to contact. let the gasket maker set up for about 10 minutes then install, this makes a dry skin on it. now install normally. this way you get NOTHING stuck to the engine parts so when you take it off you don't have a PITA job of cleaning the surfaces. only the gasket will have it stuck to it. works like a charm.
i'm sure whatever you did there was fine. MORE IS LESS>

Mongler, what was your idea behind a complete CCV delete? Doesn’t that either burn a lot of oil, gum up your intake or increase the chances of runaway? If I was going to do anything I’d vent the CCV into the exhaust somehow...if I really, really hated the environment.

You can block off the lower ccv breather hose on the block. Take the pipe from the valve cover and use an exhaust ccv extractor ventury valve adapter.
No more into the turbo with that mess.
Cant strait up delete it lol.

As an update, it appears that sealing my valve cover led to other leaks in the block, namely one on the front of the motor that I cannot quite pinpoint, but I suspect is the intermediate shaft seal. This is a brand new leak... There were previously no leaks on the belt side of the engine (all new seals done 40k miles ago.) The leak sprung up after I managed to property seal the valve cover. My only guess is that closing off the valve cover increased pressure in the block to the point where the ALH breather alone was insufficient to deal with the crank case pressure and it is now seeking the point of least resistance, in this case the intermediate shaft seal.

My hypothesis is that as these engines age and create more blow-by, they rely more heavily on the crank case breather to vent the fumes. Additionally, it is important to keep in in place to allow oil to freely drain from the turbo. So the block-off may be fine on a newer engine with fewer miles, but has caused several leaks on my engine which has at 300,000+ miles on it.

Long story short, I will be removing the block-off and going back to the stock PCV system, and I suggest keeping the stock crank case vent in place. VW engineers know what they are doing... most of the time.