Author Topic: Valve cover gasket--extra RTV? (Read 3464 times)

BimwadM42 · « **on:** December 02, 2009, 09:23:11 PM »

Greetings,

Getting ready to replace the valve cover gasket once again due to oil seepage into the #1 and #2 plug chambers. It's been almost 10 years to the day since last time, though not many miles.

Have all the parts in hand (including the bolt rubber washers/isolators).

I recall it being a pretty straightforward job last time, except it took a couple tries before I could get the cover into place without having the plug gaskets slip off.

I know about the factory-specified black RTV for the rear half-moon cutouts and the front timing case intersections, but this time, I'm thinking about trying to get a little extra measure of protection, and using some on the plug gasket rings as well. Those are the only areas that seem to have the potential to seep on my engine.

I'm thinking about using a dab to help prevent them from slipping off while getting the cover into place, and a thin bead on the head surface to prolong their life.

I can't complain about the leak-free period I've enjoyed this last time, but a little extra prevention...

Any thoughts? Advisable or overkill?

Also going to do the chain tensioner at the same time. There isn't much room in an E36 to get the cap into place if it's "popped" before installation, like some advocate. Can it be reached and popped with the VC off after installation?

Danke.

nicknikolovski · « **Reply #1 on:** December 03, 2009, 01:08:04 AM »

Don't put any around the spark plug seals. That's what the seals are designed to do. Seals don't last forever so 10 years is pretty good.

There's just enough room to do the chain tensioner but you'll need a good 3/8" ratchet and I think it was 19mm socket. (Breaker bar won't fit). It will be very tight but you'll get it. Just watch out for the coils above. The A/C lines can also get in the way. When you fit the new tensioner in the cap, push it in the timing case and then start threading it in. If you are reusing a tensioner from your car, don't bother trying to compress it in the vice - I could never get it. Just put it on the cap and push it into the timing case as far as possible and then start threading it. Tighten up and done. Start the motor, chain will rattle for a few seconds and then smooth. Replace the washer on the tensioner cap.

BimwadM42 · « **Reply #2 on:** December 03, 2009, 09:51:00 PM »

Thanks.

I will remove the coils and wiring loom to get more clearance like I did before.

My concern was that it would be difficult to get enough compression on the new tensioner and cap, and still have enough room to start the threads without cross-threading. Last time I did the job, I recall having a difficult time with the rachet in that area, and abandoned the idea of a torque wrench altogether.

How should I "release" the new tensioner before installation?

I went looking for a specified tightening sequence for the valve cover bolts, but correct me if I'm wrong, there isn't any, just a very light spec. Now that I think about it, I think I just emulated the sequence required for the head bolts last time, and it seemed to work out fine.

nicknikolovski · « **Reply #3 on:** December 04, 2009, 02:47:04 AM »

Don't worry about torque spec for valve cover bolts. Make them tight but too tight as easy to strip the thread in the aluminium head.

The tensioner should already be compressed upon arrival. For releasing, not sure what your referring too. Just place the new tensioner into the cap and fit it in. Then tighten by hand and tighten will a ratchet or try a 19mm ratchet spanner if it fits. The tensioner will automatically tension the chain under oil pressure when the engine is started.
And don't worry about torque spec. Just make it tight.

AutoXSS · « **Reply #4 on:** December 04, 2009, 10:54:01 PM »

ah, just found this and brought back a post from the past. good thing i found this....

anyone have some good pics of the replacement?

nicknikolovski · « **Reply #5 on:** December 04, 2009, 11:55:51 PM »

BimwadM42 - found the torque spec for cylinder head cover bolts M6 - 10Nm

BimwadM42 · « **Reply #6 on:** December 05, 2009, 08:29:56 AM »

Quote from: nicknikolovski;82470

Don't worry about torque spec for valve cover bolts. Make them tight but too tight as easy to strip the thread in the aluminium head.

BimwadM42 - found the torque spec for cylinder head cover bolts M6 - 10Nm

Yeah, I'm well aware how delicate the threads are. I just tighten them by hand with a palm ratchet until they start to resist. The way BMW designed the valve cover, it's not really held down by the bolt clamping pressure anyway, so it's neither necessary nor wise to crank them down.

Quote from: nicknikolovski;82511

The tensioner should already be compressed upon arrival. For releasing, not sure what your referring too. Just place the new tensioner into the cap and fit it in. Then tighten by hand and tighten will a ratchet or try a 19mm ratchet spanner if it fits. The tensioner will automatically tension the chain under oil pressure when the engine is started.
And don't worry about torque spec. Just make it tight.

Normal practice (spelled out on the wrapping of the OE part I used last time) calls for installing the new tensioner compressed and then revving the engine for a few seconds at moderate RPM to build oil pressure to spring it. It makes an awful racket when you do this and probably isn't a nice way to treat the chain and its guides, especially old ones.

Thus, the "new" method I refer to as found here in one such post; the practice of installing the tensioner in the uncompressed state.

To do this requires:

1) the new tensioner, which is compressed as you describe, to be uncompressed by some unspecified method(?)

2) adequate clearance to allow one to insert the uncompressed tensioner into the bore, and then exert enough force by hand to compress the tensioner enough to properly thread the cap

I'm wondering whether the new method is even feasible on an E36, or worth the additional hassle. I can repeat the old, straightforward method fine, but I'm mildly worried the initial thrashing will do harm to the old chain parts.

AutoXSS · « **Reply #7 on:** December 05, 2009, 09:34:56 AM »

havent got to the tensioner yet, but im gonna try the uncompressed method if i can(i have an e36). Ive read alot on here that its just nicer to the m42

I found a Nm to ft-lbs conversion http://www.unitconversion.org/energy/newton-meters-to-foot-pounds-conversion.html does 7.3 ft-lbs of torque sound right, lol?

nicknikolovski · « **Reply #8 on:** December 05, 2009, 08:23:07 PM »

That sounds right for the torque. You can change the tensioner in the uncompressed method, but all you're doing is removing any oil from inside it and your actually re-compressing it when you put it into the timing case. So just fit the new tensioner the way it came from the packaging. Don't worry, the chain will survive from a couple of seconds of rattling along the chain guides.