VCG leaks from bolt grommets

[ATB88]

Ever since the first time I've dug into my valvetrain the first time 6 years ago to do my first valve adjustment and vanos lockdown, I've been having leaks from the various bolt grommets that bolt the valve cover down to the head. I've been careful to make sure that I'm torquing them down in the correct order to the correct torque spec, and have replaced all of the grommets, and yet, I've still always had leaks.

I'm wondering if I'm missing something in how I'm going about this, or if this is pointing to a larger problem (warped valve cover, abnormally high crankcase pressure)? Has anyone else had trouble getting this right and figured out a good solution?

I'll be doing a valve adjustment in the next couple of weeks and would really like to have these leaks sorted once and for all!

[maupineda]

Buy original/genuine. Alternative, you can add a washer on those grommets, they seal through the pressure from the fastener to squeeze the rubber to make the seal, if you add a washer you can apply a bit more pressure which would help. These bolts bottom out on the stud so you cannot go crazy or you snap them. When old, these grommets just don’t seal as they are squashed.

[Halftim3]

Yeah as above use original/genuine, but what is the torque spec and is there really a sequence? I just remember them bottoming out.

[ATB88]

Thanks for the suggestions. I did replace the grommets with new OE years back, and I am using the washers under the bolts, but still leaked.

The torque spec and sequence can be seen for example here in this DIY, step 19: https://www.fcpeuro.com/blog/how-to-...-cover-gaskets

I don't remember feeling them bottoming out, so, maybe I've just been under torquing? Would it be a bad idea to ignore the torque spec and tighten to bottomout?

[01SG]

Pictures might help. Are you sure it's leaking from the grommets and not from somewhere else and cascading to the grommets?

Only place I'd think it might leak with the proper equipment and torque is at the half moons where you ought to just a bit of sealant. That wouldn't make much sense that it travels up to the grommets though.

[sapote]

Lube the ID and OD of the rubber so no scratch when installing and turning the cap nuts. Torque unit nut bottom and stop. Lube using grease.

[eacmen]

1. Clean the sealing surface between the rubber and valve cover.

2. as others have mentioned these bolts bottom out so just take your time and torque in sequence until you feel it bottom out. Don't go crazy with it though.

3. stupid question but these grommets are directional. maybe snap a photo to make sure you're not installing them upside down? hard to do but i've seen it before

4. is your CCV clogged up? its the plastic bit that goes between the valve cover and intake. blockage could cause excess pressure in the crankcase

[ATB88]

Thanks, guys. Yeah I'm sure the grommets are facing the right way, and that the CCV pipe is clear. It's possible that my torque wrench is miscalibrated enough that I'm just not torquing them enough -- I've always torqued them to spec, not to feeling them bottom out. I'm just gonna go ahead and replace the full set of grommets, cap nuts, and washers, and make sure that the nuts (barely) bottom out.

[maupineda]

You don’t need torque wrench. A hand driver is enough and you can clearly feel when it bottoms out.

or… your cam cover is warped beyond acceptable. These are not perfectly flat.

[Cubieman]

You don’t need torque wrench. A hand driver is enough and you can clearly feel when it bottoms out.

or… your cam cover is warped beyond acceptable. These are not perfectly flat.

I have never had the grommets leak, but the tube seals are another story, I have genuine everything for seals and cyl. 3 leaks, I'll have to fix that soon.

About the valve covers and flatness, you are right, they are definitely not perfectly flat.
I was worried mine was warped as I could never thread in the banjo bolt for the drain line until I had multiple bolts secure to pull down the cover a bit.

I took out a staight edge and to my shock found that the valve cover was indeed not 100% flat.

I immediately spent ~$700 to purchase a new valve cover and found...it was indenitcal to my original cover and not flat.

Those were the early days when I didn't know much and spent WAY to much time and money obsessing over little things like that.