I am in the process of replacing the oil galley plugs & in doing so I have ordered new "stuff" for the valve covers...there are no torque specs in the Porsche manual in the directions for installing the valve cover....do you just tighten them down till the bolt tightens as I notice there is a flange on the bolt which would act as a "stop"....most valve covers I am acquainted with do not have this feature...also should I use any type of adhesive between the cover gasket and the head?
Thanks in advance for any input!!!!
10 Nm / 90 in-lbs.
be extra careful of the back-bottom bolts on each side, under the coolant tank and under the brake booster. Very hard to get at if the bolts get messed up. for me, on one side the head of the bolt stripped, on the other side the bolt broke while removing ( flush with the head :( ).
David R. Hendrickson
'88 S4 AT Silver Metallic
Leaking Cam Covers - Advice Please
1990 S4 Auto.
Since my inlet manifold refurbishment (new cam cover gaskets etc) my cam covers have leaked oil around the gasket seam. I've now got a new pair of cam cover gaskets, have removed the cam covers, cleaned all up and am ready to reassemble.
What sealants should I use where so that it doesn't leak oil this time? Any special 'tricks' I should know about?
Many thanks in advance,
You must put a good slather of Yamabond/Hondabond or RTV in the 4 corners, as shown below, points A. Other than that, I don't put any sealant on the gasket other than some real sticky goop to hold the gasket in the cover during installation. The gasket tends to pull out of the corners and can get pinched if it is not stuck well to the cover.
The factory installed some "spacers" between the thrust washer and the bolt on the lower bolts (points B) to increase the clamping force starting sometime mid 87. I don't think they continued this practice long. My 89 did not have them. However, many people have gone to installing them, some even do it to all the bolts.
Yes I should have also said: My cam covers did not originally have any of the spacers, and I reinstalled them the same way and they both leaked. I then added one spacer to ALL bolts (I had an equal number of spacers as bolts in my packet of new parts so I assumed...). But both covers still leaked so I added a 2nd spacer to the bottom row only and still both leaked. I'd also applied sealant to the 4 'corners'.
And that was with the engine nut and I still got it wrong - much harder with the engine in!
I'll follow your advice and see how I go.
PS JG If you are reading this and want to sell me a couple of hours on Saturday to help me nail this properly since you've done it once or twice (after our bike ride, weather permitting) give me a call. Tried calling you, no answer. :-)
Well, you already did the standard stuff I mentioned and went further with 2 spacers. Engine out, it's hard to mess this up, and so I'm not sure why your covers would be leaking. Maybe someone has some other suggestions. I don't. I assume you cleaned and inspected the mating surface on the heads.
Check the condition of the cover groove the gasket seats in. On mine the factory coating was flaking off and /or gone in may areas. I cleaned /scraped out all the remaining paint from the groove, degreased and applied a thin coat of Hondabond to the entire groove and to each spark plug tube surface as well as the four corners. No leaks at all.
Dave, see the thread "Experts: please school us on sealants, thread lockers, anti-seizes, and lubricants" http://forums.rennlist.com/rennforums/928-forum/592090-experts-please-school-us-on-sealants-threadlockers-anti-seizes-and-lubricants.html
Some of the discussion in that thread is related to sealing those gaskets.
Also, when you took out the old gaskets, was there any evidence that they hadn't been seated in the cover grooves properly? FWIW, based on some advice I came across here on Rennlist somewhere, I used dental floss to hold my gaskets in on the troublesome four spots on each cover while replacing the covers; that floss pulls out easily (before tightening the bolts very much) after it has done its job. Also used a small bead of YamaBond 4 between the gasket and cover based on advice from Mrmerlin.
'90 928S4 black/black
only use a small amount of RTV in those corners. Do not cover everything with RTV or it will leak.
Use only 1 spacer ring on each and every bolt.
I have done countless cars this way and dont have any leaks.
Anyone have a pn for the space rings?
I also have a leak, and it can cause oil smoke from the car.. Scary
900.123.144.30 (also known as N0138112)
I used a --thin-- film of Hylomar in the clean cover grooves to make up for possible gaps, roughness, defects, whatever, that might allow oil to sneak past. I used the same thin film on the plug well seals both sides, and on the bosses in the cover where the plug well seals fit. For the corners, Hondabond, Yamabond, SeaDooBond, or in my case a bit of Permatex Hi-Temp Gasket Maker RTV. An inch or so either side of the corners is plenty. Smeared the rubber bolt seals inside and out with the Hylomar too.
I used small/thin cable ties to hold the gaskets to the cover during installation. Those plug well seals do like to move around, so I used a small inspection mirror down the plug wells to verify that those rubber donuts are in the right places. Took a couple tries to get the plug well seals just right, while the gasket was perfect the whole time with the cable ties holding it. Once the covers was seated, I just cut the ties and pulled them out gently, as I put each bolt in. Middle bolts snugged to hold the cover and gasket down as I progressed from one end to the other with the cutters for the cable ties, following them immediately with bolts. Used the little mirror to verify that the gasket didn't move as the ties came out and the bolts went in.
No matter what, get out ALL the rags/towels/whatever that you are using to block the oil return galleys in the heads. Hopefully before you put the covers on for the first time. Not admitting guilt here, just sayin'...
Dr Bob '89 S4 Auto, black