Oil leak advice

[Doddsy]

Can anyone please advise how I should stop the following oil leak. I finally managed to identify the source of an oil leak from my engine. It isn’t pouring out but is enough to make quite a mess. The culprit is one the bolts that secures the alternator bracket to the engine. It also secures the water pump and passes through the timing cover. Looking at the Timing Cover diagram (25.23) in the Parts diagram I think it is UCB131/30R (there are two) - the upper one. I have removed the bracket a few times on various projects so I presume it is something I have unwittingly caused. The oil seems to be coming out from around the bold head. There is a domed washer installed but nothing else to seal this. Lots of time on my hands currently to sort out a few issues! Thanks Nigel.

[politeperson]

Have you examined the 5/16th head studs that point downwards at the front of the head?

They are tensioned by half inch nuts that pull through the thin section of the head gasket around the timing chain. I think their are 6 in total, 2 at the front above the water pump and 2x2 either side.

Are they tight? worth checking with a spanner.

I have stopped leaks in the past by giving them each a quarter of a turn.

If the leak is from a water pump stud then you could undo the bolt, paste it and the washer with gasket compound (Wynns?) and re tighten it.

[angelw]

Hello Nigel,
There is a rubber plug just above the right hand end of the water pump, just inboard of the Alternator Bracket; this plug is to gain access to the timing chain adjuster. Clean around that thoroughly and observe the area around there to see if it oils up. When oil leaks from there and its a common problem, it migrates down onto the Alternator Bracket and gives the appearance that its leaking from around various bolts.

I have a car in work for an oil leak from the general area of the Alternator Bracket and that's where it was traced to. Should that be the case with your car, care should be taken when removing the plug. They seem to harden over time and the two lugs (on most, but not all of the plugs used) that resist the plug from working forward, are easily broken off and fall into the timing cover area.

The safest method I've come up with, is to screw a small diameter, self tapping screw into the plug out towards the circumference of the bore into which the plug fits and then cut that sector out (like a helping of a round pie) and extract it with the screw. Screw a self tapper into the remainder and you can collapse the plug enough to safely pull it out.

Regards,

Bill

[lowact]

If you lose any of the rubber plug into the timing cover, don’t worry about it, there is nothing in there that would be in the slightest bit compromised by a bit of (short-lived) gnarly old rubber. Which reminds me, I’ll be needing a new one, thx.

Yr problem cannot be the bolt hole, that bolt clamps a gasket (C29337-RH) that separates coolant at water pump pressure from oily air (behind the timing cover) at atmospheric pressure. For anything to leak out of the bolt hole the gasket would need to be broken, if it was broken it would be water leaking out, and not just from the bolt hole.

Don’t drop the screw.

Also check yr crankcase ventilation system if the filter (C3674 on 26.21) is fouled, yr more likely to be getting oil leaking from the subject rubber plug (C30470 on 25.23).

[Ole-xke1974]

My timing chain access plug was hard as a piece of coal when I worked on the valve clearances a few years ago. I fitted a new plug and added a small spring loaded "clamp" to keep the plug from weeping oil.
Under the aluminium bracket is a spring pressing on a washer.

[Doddsy]

Many thanks James, Bill ,Colin and Ole. Your advice has been most helpful. I managed to get into/under the car today and found that the cylinder head front stud/nut immediately above the alternator bracket was loose, embarrassingly so!

A quick fix to tighten this up and a warm up on the drive (Im not in favour of going out in current circumstances). The oil Leak from here seems to have stopped completely. James, you certainly know your V12 oil leaks!

Only problem now is that there is definitely a water leak from the same are, probably the water pump gasket. However there is also a more substantial oil leak from the oil filter. I have installed the Coolcat Spinoff adapter which has been problem free for five years or so. The drip appears to be coming from the adapter to filter head o-ring. I have just emailed them for info about the seal replacement.

Ole, I too fashioned and installed a spring steel plug holderingee. Never managed to photograph it as well as you. It is still in place and doesn’t appear to be leaking (yet).

Anyway lots of time on my hands right now to learn even more about my car (which I have had for 38 years!). Thanks all again, great forum….

[Doddsy]

A quick update of my lockdown efforts to stop/reduce the various fluid leaks that have been messing up my garage floor for too long and a request for one more piece of advice.

The new seals for the spin on adapter arrived from Coolcat. I cannot recommend Coolcat highly enough. Mike, if you are reading this a massive thank you. Great service despite the challenges of the crisis. I was able to fit the new seal easily and have now filled up my car with new oil, new filter and run her up to temperature All is good, not a leak in sight.

Looking at the old seal you can see that it wasn’t twisted (the edge of the adapter can be seen all round one face). The only things that I can thing is that it seems to be a bit hardened compared to the new or more likely that it could have done with being fitted a bit tighter. The bolt undid quite easily.

Having washed my garage floor I was pleased to see that almost all is now foreign fluid free. The only exception is a small leak at the back of the gear box (I have refilled the gear box). The upside is that this provides a self lubricating system to the rear gear box mount! My question is whether it is possible to replace the rear gearbox seal insitu or is this an engine and gear box out (why didn’t I do this before when the engine was out? Ho hum). If it is possible then any recommendations. If not then I will continue with the annual gear box refill for a bit longer.