High oil pressure and rear oil seal leak.....

[French Collection]

From searching the forums, people are obviously more concerned with low oil pressure.

However, I may have the opposite problem. The oil pressure gauge is off the scale from cold and stays that way most of the time. Admittedly, I have only done 40 miles on the road so most of my observations are based on running the car in the garage.

The engine has been completely rebuilt as part of a complete restoration. I have filled the car with Millers running -in oil. I also fitted the Barratt spin-off filter conversion and had the crankshaft machined to accept the modern rear oil seal (more later).

I know the oil senders are not very accurate, but I have tried 2 (one supplied by Ken Jenkins), with the same result. Gauge has also been re-furbished.

I do suspect that my alternator is over-charging. Could this affect the oil-pressure reading? There is a voltage stabilizer to prevent this I think?

Could there be a problem with the oil filter conversion? How does the pressure relief valve work in these?

Now to the rear seal....

Maiden voyage, 40 miles, went well. Everything worked, nothing fell off. Except that there was oil burning on the exhaust. First I though this was oil blowing out of the oil breather (engine was a bit overfull), as I have pancake filters at the moment and left the breather pipe open.

However, further inspection (with the front of the car jacked up and engine hot) revealed a steady drip (one drop every 5 secs or so) from the drain hole at the front of the bell housing. It doesn't smell like gear oil, so I am sure it is leaking from the rear seal.

Did I make a mess of fitting the new oil seal? Or is the oil pressure really too high and forcing the oil past the seal? I don't think the fact that the car is jacked-up should make a difference?

In theory, as the seal has a split and is retained by a spring, the seal can be replaced in-situ by removing the sump. Has anyone got any experience of replacing these seals in-situ?

Thanks for reading and any advice and suggestions.

[Moeregaard]

I would verify your oil pressure by temporarily fitting a modern mechanical gauge (VDO, Stewart-Warner, etc.). Unfortunately, I have no experience with the rear main seal modification and cannot offer an opinion here.

[cactusman]

And if a modern hydraulic gauge shows the pressure as very high I would guess the bypass pressure relieve valve is either stuck shut or mis-assembled. It is in the base onto which the oil filter screws on.

[288gto]

Also, quote "(engine was a bit overfull)" this won't help. I'd drain the oil and put the correct amount in.

Simon

[64etype]

I inspected the clamshell design kit and the Terry's two part GM seal kit before selecting the latter. I doubt the seal in either kit could be replaced with the engine in the car. But Terry Lippincott at http://www.lippincottsgarage.com in Reading, Pennsylvania could tell you for sure. He has successfully installed a number of both versions. I have run the rebuilt engine in my car for about ten minutes without leaks, but the upcoming road test will tell the story.

Are you sure the leak is not originating at the cam cover seals or the cam oil feed banjo fittings?

[French Collection]

Hi Eric,

The leak is not from the cam covers or camshaft oil feeds. The drip is clearly coming from inside the bell housing which means either rear crank seal or gearbox seal.

Since I posted my query, I changed the oil breather assembly with parts supplied by Ken Jenkins in the UK. I don't understand how exactly, but this new arrangement which has a plate with 2 x 1" (approx) holes instead of the gauze filter inside the breather assembly on the front of the cyl head prevents / limits a build-up of crank case pressure.

I ran the car up to temperature and no drip so far. Let's see what the next road test brings....

[French Collection]

Also, quote "(engine was a bit overfull)" this won't help. I'd drain the oil and put the correct amount in.

Simon

Hi Simon,

I did drain and re-fill with the correct amount of oil.

Brian

[64etype]

[quote="French..]]

Since I posted my query, I changed the oil breather assembly with parts supplied by Ken Jenkins in the UK. I don't understand how exactly, but this new arrangement which has a plate with 2 x 1" (approx) holes instead of the gauze filter inside the breather assembly on the front of the cyl head prevents / limits a build-up of crank case pressure.

[/quote]

Interesting...that baffle is the one depicted in parts manual for early 3.8 breathers (mine has the screen). Hope it works. Let us know.

[French Collection]

Yes, Ken said it was the arrangement used on earlier E-types.

If it stops raining by the weekend (yes, it does rain in the south of France), I hope to get out for the next test drive.

Will certainly let you know how it goes.

Brian

[Hugo]

[quote="French Collection"]Hi Eric,

The leak is not from the cam covers or camshaft oil feeds. The drip is clearly coming from inside the bell housing which means either rear crank seal or gearbox seal."

No matter where the leak originates, it will drip off the lowest point! Don't be fooled.

[French Collection]

Eric and Hugo,

Eric was right, there is some oil leaking from the camshaft feeds. I have tightened these again so hopefully it will eliminate one leak. Still have a leak, but not as bad as before so the new breather arrangment seems to have helped.

Brian

[French Collection]

So, I finally have a leak-free car (well, more or less).

There was still a leak from the blank on the bag of the RH cylinder head which had the wrong O-ring fitted. When I replaced the O-ring that solved the remaining engine oil leak.

The gearbox oil leak, on the other hand, got worse. As it didn't seem to be coming from the rear oil seal I decided to remove the exhaust so that I could have a good look around the back of the gearbox. When I was taking the exhaust off I found a small bolt sitting between the 2 silencers. I proceeded to feel around the back of the gearbox and eventually found the corresponding washer sitting in its place above a hole on the oil pump on the back of the gearbox. Refitted the bolt in the hole, cleaned up all the oil and topped up the box. End of problem!

[64etype]

Good news. Thanks for following up.