Oil leak

Tom W

Active Member
My car’s started leaving a patch of oil when I park up. It’s more than the usual occasional drop, so it’s something I need to sort. The puddle forms under the engine to bell housing joint. My first thought was that it will be the cylinder head o-ring, but the amount of oil on the side of the block doesn’t seem to be that much compared to the leak. There’s also a leak from one of the external oil pipes. I’ve got a box of assorted O-rings, so can try replacing that if the O-rings are a standard size.

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I had oil leak and found was in part from rear of inlet manifold gasket area. replaced gasket ( not a 5 min job !). and reduced. leakage but still need oil tray when parked overnight. now oil from front end of my 3500 engine area. not located as takes so long to drip down but as its very slow ..I have taken view that liek many old cars such as Land rovers.. they have a natural tendency to leak somewhere !


Well-Known Member
Yeah, that’s the head gasket o ring. It drains pretty quickly down the block when the engine is hot then pools afterwards. Bear in mind that the o-ring is on the pressure side of the oil system so will not show the full leak unless the engine is at sustained higher revs.

Tom W

Active Member
Sounds like it probably is the head o-ring then. It definitely drips more when the car’s driven quickly, over long distances.

I should probably refurbish the head whilst it’s off too, and convert it to unleaded.
I just replaced a very old, very thin, cracked valve cover gasket with a silicone one, and it seems to have significantly reduced my oil leakage, which I thought might have been something far more serious, given how much there was, and how it was blown all over then engine block by the fan. It might be worthwhile to give that a go, before going after the head gasket. As a bonus, the silicone gasket is re-usable.
I hadn't heard of silicone gaskets so will be interested to hear how it lasts. I did try a rubber rocker cover gasket once from one of the main suppliers but it turned out to be a piece of junk. When I removed the cover a year or so later I found that the rubber had perished and bits were coming off the inside.