Valve cover gaskets: to seal or not to seal . . . that is the question

[milodub]

I'm a new owner of a 06 S4 Avant MT with about 66k on the clock. Really enjoying the car and now learning how to work on it! VCGs are next up. I've read a lot of posts and found some great DIYs (thanks to Jimmybones and Joeycurraco) but wondering if I should use any RTV sealant or just install them dry? Thanks!

[jvitelli17]

I have been debating as well, they were done by PO at 80K but at 111k im thinking about redoing them because i am going to get them powder coated. I will use RTV on the half moon's on each VC. I like to put a little on the major turns but i keep it off the straight parts of the gasket. This way, if you have to re-do the gasket your not scraping off old RTV for hours!

The way our VC looks i'd say put RTV on half moons and the lower corners because the oil will likely leak out the lowest point/corner. That is just my .02

[SprintBlueWorld]

Just did the passenger side last night on my 2008 s4 cab with 56k miles. From the factory it appeared to me they put a very small dab on the top rail corners. It looked to me like two differant pieces of metal meet there which could be slightly uneven and would explain why they gooped it. Other than that factory appeared like dry install.
Jhm recommended a thin even layer on both sides of the gasket which is what I did with permatex ultra grey rtv. The side facing the valve cover I only covered the top surfaces not the sides.
Rtv or not it will work. However, jhm and majority consensus seem to favor some amount of rtv as it will allow the seal to last longer although surface cleaning will be more difficult next time.
On a side note my coil pack seats were a pita. I used a small hammer and a chisel and gently went around them til they popped out. Just pulling them out seemed impossible as they appeared cooked to the vc seat.

[viridia]

Use RTV unless you want to do the job twice.

Either the gaskets weren't manufactured thick enough or the bolt spacers are too tall - something went wrong in the design. The bolts do not provide enough clamping force on the rubber for a good seal.

If 2mm of material was removed from the height of each bolt spacer RTV wouldn't be necessary.

[emcaha]

I RTV'd as well. Not going to hurt anything and if JHM recommends then it's probably best to follow their lead. Coil pack seats definitely take some elbow grease to get out.

I also did IM spacers while I was in there. Nice having a little extra room to do the VCG's and thought it was a good time to give the whole topend a lookover and cleaning. Overall, pretty straightforward and wasn't very hard.

Best of luck.

[Wiggler]

wondering if I should use any RTV sealant or just install them dry?

I did them dry 1.5 years and about 15kmiles ago, holding up fine so far. Gasket is a thick rubbery thing, didn't make sense to me to add goop from a tube some places but not others. That said, factory used the black high temp sealant at the corners, I cleaned that off.

[blocke]

I did mine at 55k or so for the first time. The factory gaskets were leaking on the front of both heads. I scraped all the factory stuff off, and used RTV on the entire thing. Both sides of the gasket.
Been checking them religiously since, and no sign of a leak, weep or otherwise.

[milodub]

Great info and I appreciate all the advice. I'll pick some up and take a good look when I get the VCGs off and go from there.

[SpoolBus]

Permatex "the right stuff" google, buy never do again

[audi49]

I did mine with a black perma-tex high temp rtv, about 3 years ago. No leakage whatsoever since. So i'm in favor of adding a very thin layer of sealant on both sides of the gasket. I do agree that it may be a bit of a bear if it has to be replaced again some day down the road, but I think it's worth it.
I'm presently replacing the VC gaskets on my older A4 and will also use sealant.

[luvsspeed]

I'm planning on doing this job in the next few weeks, I did not see a point in starting a new thread. Has anyone had any experience using this sealant?

https://www.permatex.com/products/ga...-gasket-maker/

[924Carrera]

I used this. https://www.amazon.com/Permatex-8218.../dp/B0002UEN1U

I do highly recommend using it especially on the stepped transition between the timing case and the cylinder head. Those surfaces look like they were intended to be flush, but at least on my car, they were not. Don't go crazy with the stuff, because too much can actually cause problems plus it becomes very difficult to remove the next time. However, if you put them on dry it's very likely you'll be doing the job again sooner rather than later.

[Terry.Reese]

https://www.europaparts.com/valve-co...OtURoCeTTw_wcB

I used RTV on the half moons, next time I will do the corners as suggested as well to help prevent leakage.

now to just redo the oil pan gasket as well....

[RPMtech147]

Just in the corners of the 1/2 moons...

[luvsspeed]

Hopefully I will be doing this tomorrow and I already have a second set of valve covers. I take it the general consensus is to do the corners and half moon seals on the block side of the gaskets?

[VinnysS4]

I swear by this stuff http://www.ebay.com/itm/like/1517628...&ul_noapp=true

When I did my covers, I didn't know about it. I used RTV all around on the gaskets. Wish I hadn't.

[Fourpoint282]

my thoughts:

do the work yourself....it only builds the relationship with the car :)
take this time to PC the VCG's. I did red and well worth the time and money. Cost is about $50-$100 depending on what they charge in your area. Really cleans up the engine and adds a nice pop of color under the hood.

i've had to do, redo, redo and redo my VCG's because I could never get a perfect seal on the head so there was always this slow (and smelly) oil leak. I used a small bead of black RTV in key areas of the gasket to hold it in place while reinstalling on the motor and solved the oil leak problem. Also, splurge on decent gaskets...dont get cheap ones or you'll just be doing the work again in a few thousand miles...and anyone who has done this before knows there are two PITA bolts on the back of the motor that make this job VERY challenging and time consuming = frustrating afternoon, a lot of swearing, and back pain.

Good Luck!

[Terry.Reese]

and anyone who has done this before knows there are two PITA bolts on the back of the motor that make this job VERY challenging and time consuming = frustrating afternoon, a lot of swearing, and back pain.

Good Luck!

especially when one of them was stripped, had to tap that damn thing to fit another size torx bit.. good thing I bought all new bolts, 5 total were stripped.

[Fourpoint282]

especially when one of them was stripped, had to tap that damn thing to fit another size torx bit.. good thing I bought all new bolts, 5 total were stripped.

Word, I had to use a cutting blade to cut the head of one off my bolts first time around. Sparks flying everywhere around an engine filled with 93 oct fuel....very fun afternoon! Total newb moment and boy did I learn that lesson.

[neilpaku]

Terry, what size did you tap that hole to? It's currently an M6 I think. I have the one on the passenger side stripped (new bolt though) and it's applying "some" pressure, combined with some sealer will hopefully not leak. But I really would prefer to fix the hole so I can tighten it to the prescribed torque. Was thinking of either fitting a helicoil if they make them that small, or just tapping it to M8 and then increasing the size of the hole in the seal bushing that fits into the valve cover so I could retain the original sealing method but with a larger diameter bolt.

[Terry.Reese]

we tapped the head of the bolt, not the hole. hammered a higher size torx bit into it and finally got it to turn correctly. the top of the bolt was stripped, sorry for the confusion.

[neilpaku]

Ah got it - oh well, I shall continue on my quest : )

[Bhee7]

Just did mine last Sunday, only rtv on the lower part of the half moons, for the left side problem bolt I bent a 1/4 in aluminum nut driver a few times until I got a good angle, cracked it loose no problem right side, 1/4 extension and swivel torx did the deed for me.



.

[Rol-co]

Old topic but anyone modified the vc bolts to get more pressure at the gasket? Want to try with stretching over a 2mm O-ring behind the rubber part.
It should get a little more pressure at it.

Have one leaking oil, even with a little sealant, doubt if there is enough force at it.

[Rol-co]

Added a O-ring behind the bolt rubber for 2mil extra pressure on it, fingers crossed! Hope no leaks anymore there.

[Matthewest91]

In my experience, it seems like there is always at least one of the bolts that does not clamp well. Not sure if they are partially stripped or what but I started to use rtv around the entire circumference.
Keep us posted if this works ?
Which o-ring did you use ?
So no rtv and just the larger o ring ?


Sent from my iPhone using Audizine Forum

[Rol-co]

In my experience, it seems like there is always at least one of the bolts that does not clamp well. Not sure if they are partially stripped or what but I started to use rtv around the entire circumference.
Keep us posted if this works ?
Which o-ring did you use ?
So no rtv and just the larger o ring ?


Sent from my iPhone using Audizine Forum

I put a 8x2mm O-ring behind the top edge of the bushing and rubber on the bolt, stretched it gentle over that top edge. Used some rtv at the half moon's and bottom corners.