Hi Gents, I recall some info on here about an O ring on the oil pressure safety / relief valve that could be the cause of a leak and also the O ring of the oil pressure switch. I know where the oil pressure switch is but not the pressure safety valve, guidance appreciated.
Also, if the rocker gaskets are replaced is there any need to renew the inlet manifold gasket ?
Finally I've tried my selection of metric sockets on the outer bolts of the rocker but none fit - is it non-metric ?
I have a nuisance leak - steam clean on the way.
Thor 4.0

Rocker cover gaskets are a common leak source. Bolts are 8mm but 12 point not 6 point like you normally find so you need a 12 point socket. No need to replace the inlet manifold (aka Valley) gasket unless for some reason you decide to take the inlet manifold off, which you don't need to do to change rocker cover gaskets.

They're Bi hex 8mm..

Mine leaks like a sieve..

Thanks for the quick reply - any info on where the pressure relief valve is, or was I reading about a Gems ?

Pressure relief valve is part of the oil pump.

No were near the rocker covers ;)

Thanks - the fan blows the oil everywhere, difficult to locate the source - hence steam clean

The valley gasket can also be the source of leaks (well really the rubber seals either end can be). If your going as far as rocker cover gaskets trying to remove a leak its worth a look at the front and rear end of the valley gaskets as your most of the way in there by the time the upper manifold is off anyway. You can see both ends of the valley gasket from above - look for the metal plates, the rubber seal sits under that. (Disco 2 with Thor here, but its the same engine). Rear one is likely to be dripping around/onto the starter motor, I would guess the front one would end up dripping down onto the oil filter area, possibly onto the same area around the pressure switch.

Mine had gone completely brittle on investigating and the rear one was leaking badly. Thats now only stopped part of it, looks like the rear crankshaft oil seal is also leaking, as having stopped the leak from above, it can be seen dripping from the bellhousing now.

Had the leak from the oil pressure switch a few years back, though that was down to someone prior to me not doing it up properly as it wasn't even finger tight when investigated.

Where is the worst of the oil appearing?

Rocker cover bolts as said above, I ended up buying these
https://www.halfords.com/tools/hand-tools/socket-sets/halfords-advanced-11-piece-3%2F8in-drive-deep-socket-rail-611610.html

But you might be able to just find an 8mm socket cheaper. I needed them there and then as we already had the upper manifold off.

Mine leaks oil out of everywhere!

Might be your front cover of Valley gasket.

Mine leaks mainly out the valley..

The fan does blow it everywhere!

Thanks Brian, can the seals be easily replaced - or must I remove the valley gasket to access them ?
Apologies for being so thick - but it's a job I've never done before.
I checked YouTube for the rocker gasket repair and that seems not too bad a job.

We managed to get in there and get most of it back together in the same day. If your only running petrol (no LPG) it might go back together in the same day. Valley gasket needs to come out to replace them (the bolts go through the gasket at either end as well as the seal, seal sits under the gasket).

Seals are number 7 on the link below
http://new.lrcat.com/#!/1234/90127/90555/7181

Photo of the rear one on mine, you can see the obvious leakage

There are two welch plugs on the oil pump body. One near the oil filter and one on the opposite side. They are o-ring sealed. After a while the o-rings give up. Mine did and within a week I went from reasonably oil tight to leaving a patch of oil on the ground the size of your hand every time I stopped. I thought it was the filter gasket as the oil was dripping off the filter and the front engine cover.

The one on the filter side is a pain, but not difficult. Oil filter off, bottom radiator hose off, circlip off, plug out CAREFULLY so as not to have the relief spring end up somewhere in the garage (you might have to push the plug in against the spring a few times to get it moving), new, very thin and special o-ring (best get the right spare before you start) and then put it back together. Whilst there, change the o-ring on the oil pressure switch.

The one on the LHS is the same procedure, but a lot easier to get to, and as is Sod's Law, rarely leaks.

Great info - thanks for the schematics link. I'm on LPG (fitted by Simon and working admirably).
The RR is my daily transport - looks like an 8am start is on the cards

What year is it? On a GEMS the rocker cover gaskets are pretty straightforward (having done mine a few weeks ago) but did a Thor last week and the solid coolant pipes and alternator make getting the RH one off difficult and they both have to come off.

On the issue of non-metric fasteners, there seems to be quite a few SAE bolts on the engine itself, I think still a carry over from it's Buick origin.

Gilbertd wrote:

What year is it? On a GEMS the rocker cover gaskets are pretty straightforward (having done mine a few weeks ago) but did a Thor last week and the solid coolant pipes and alternator make getting the RH one off difficult and they both have to come off.

It does say Thor on the bottom line of the first post, and your mentioning this reminded me of the same. No A/C compressor on mine, but the alternator did have to come off to get the manifold off. Left the solid coolant pipes in place on the manifold on mine, just disconnected the rubber pipes. Having seen the state of the coolant pipes there, I would have replaced them if I'd known they were that bad there and then. Might be slightly different on a p38 as I'm not sure the setup is identical for plumbing.

If your going to go that far I'd at least have a look before you order bits to see if the seals are leaking, as your already most of the way there then. And label the lpg pipes so you know what your putting back to each injector before you pull them off, as if they are in the lower manifold you can't tell which one is which after the upper one is back on (assuming your injectors are ontop of the upper manifold and the pipes go through the webbing to the lower one, which is likely if Simon has fitted it as thats the way he recommened to me).

Missed that. If taking the lower inlet off then yes you can leave the metal pipes attached to the manifold bit if only taking the rocker cover off, then at least one of them needs to come off (the one from the inlet manifold) or you can't lift the cover clear of the rockers.

Cheers for the info Gents, I have to say at 71 yrs old I'm not looking forward to the job - if you see a Y Bordeaux on eBay then...........

I'm 65 so not far behind you. Spent all of yesterday working on my car and doing a headlining on another at the weekend. It's what keeps us young.....

You'll find it helpful to superglue gasket to rocker cover before refitting

Simple thing to watch out for when you do get to the rocker gasket, mine had gone so distorted that the metal inserts dropped out of the rubber (theres one round each bolt). You obviously don't want them to drop anywhere in the engine but if your aware they are there, at least you will know to watch out for them. One of mine dropped down somewhere in the valley and was retrieved with a magnet pickup tool.