Oil leak help

[beetos]

Hi guys, hope everyone is enjoying the festive season!

I have been tracking down a quite major oil leak and thought I nailed it. The rocker cover nuts were loose so I thought nipping them up would solve a leak from the front / top of the engine on the exhaust side. There was sign of oil stains from the rocker cover corner so I had my hopes pinned on fixing that.

Unfortunately, it still leaks like a bastard. Today I went for a run and popped the bonnet to find oil pooling and dripping off under the boss that houses the chain tensioner spring. I am thinking it might be the cam seal or upper cam housing.

There are some really good pics of the area, as well as others at this great site for anyone contemplating a turbo conversion with access to 745 bits.

http://www.islandia.is/smu/structure/645csi_project.htm

You can see one that site the donor motor had a shot cam seal and leaked like mine is doing, down the front/top exhaust side of the motor, so I am thinking mine might be fk'd also. Becuase I don't have a dizzy and just a blanking plate, I am assuming that all I will need to do is reseal the cam housing and not change any oil seal as such looking at the OEM picture

http://www.realoem.com/bmw/showparts.do?model=HD12&mospid=47382&btnr=11_1187&hg=11&fg=25


Can anyone advise on how difficult is is to change the cam seal and reseal the front housing? I would probably do it with a valve adjustment.

Cheers

Edit P.S. Oil/water look ok so I don't think its a blown oil gallery in the head gasket..

[pundit]

One of the most common (and misdiagnosed) M30 oil leaks is from around the larger of two bolts that retains the crank angle sensor bracket (http://www.realoem.com/bmw/showparts.do?model=HD12&mospid=47382&btnr=11_0144&hg=11&fg=10). (Bracket shown as No.10, bolt is No.12)
The bolt becomes loose and oil works its way along the bolts thread and out onto the bracket. The oil then drips down onto the crank pulley and is flung off either giving the impression that either timing cover seal is leaking or some other cause etc.

Here is a link re. this leak http://www.koalamotorsport.com/article-m30oilleaks.asp

I had this problem with mine! It's a bit tricky to get to but if you find the bolt is even a little loose then that's most likely your leak! - Good Luck

[beetos]

Great tip, thanks for that.

I'll look at that bolt first and then take it from there. I really hope thats the culprit.

[Kalevera]

The chain tensioner has a crush washer on it that may need to be replaced, but you'll have to re-prime the tensioner itself if you open it up.

How difficult is it to change the cam seal and reseal the top cover? That's gotta be a joke, right?! :) If you built that car, it should be an hours worth of work:

- Remove valve cover
- Pull distributor cap + rotor
- Pull cam end cap (a ~ 7 or 8 hex, if I recall correctly)
- 3 x 10mm headed bolts on each side of the top cover, plus two where it meets the lower cover. It uses a gasket on each side. Use a razor blade to really clean up both the aluminum cover and the block; carefully clean up the mating surface @ the head gasket and be very careful not to damage the head gasket. I use a TINY amount of RTV on the points where the edge of the lower and upper timing cover + engine block meet, with an emphasis on *tiny* -- you don't want that **** in the crankcase.

If you can work around the lower rad hose, it's an easy job.

best, whit

[beetos]

Sounds easy enough, thanks for that.

I have not poked around inside an M30 before as the previous owner(s) did the motor. I have have tore down plenty of other motors so there should be no drama. Cheers for the tips.


Edit: after inspecting that area, I found the M6 bolt on the lower cover, right under the chain tensioner boss completely loose. The one above it on the upper case (the lower of the 3 on the exhaust side) is stripped and wont hold any torque. With luck, nipping up the one that was loose should make a difference. Now I have to see if I can repair the thread on the head for that one upper cover bolt:(