The V8 Owners Forum -

Hi folks,

I'm in the process of dismantling my rover v8 engine for fitting new piston rings (see previous topic on oil consumption), and i've noticed that almost half of the valve stem seals have popped off the top of the valve guides. It's random between inlet and exhaust valves. See photo (see the valve on the right!):



It's an old SD1 engine that originally had the crap umbrella type seals, but during the first rebuild I fitted the late type valve guides and proper neoprene valve seals. There is no valve retainer to seal contact going on, and it's got a stock 3.5 cam.

Any idea why they might have come off, and how I can stop them coming off in the future. Can they be loctited on for example?

Cheers,
Jeff

were they a tight fit on the heads

ian.stewart wrote:were they a tight fit on the heads

Seemed like a tight-ish fit. I used a socket to push them on, and it took a firm thumb pressure to get them on. The seals themselves came from ebay, but were supplied in a land-rover branded packet, and looked to be good quality and geniune.

They've only been fitted for a few thousand miles too. Can't do the valve guides any good with that seal bashing up and down, can it?

I'm tempted to fit the old rubber washer type seals instead, but are they a complete waste of time?

Jeff

They obviously havent gripped the top of the valve guide pproperly. But I would think they would still act like the old washer type even though they have come loose. When the valve is down, they will probably still hold back a bit of oil. I've just fitted these to my new engine. It will be interesting to see how they are after a few months when I pull it out for a check up.

Or, they were dry when installed. Maybe they were stuck to the valve when it returned to it's seat?

Did you lube the valve stems when you fitted them?

Boosted.

I used some oil and a rubber mallet to get mine on. Bloody tight they were!!

That happened to me when I pushed them on firmly with a socket thinking they were 'home', later found that they needed a very firm tap to get them on and all I'd done was get the edge of the seal onto the very end of the guide. I suspect that you mad the same mistake.

GreenV8S wrote:That happened to me when I pushed them on firmly with a socket thinking they were 'home', later found that they needed a very firm tap to get them on and all I'd done was get the edge of the seal onto the very end of the guide. I suspect that you mad the same mistake.

I couldn't have got them on any further, since they are touching the step at the top of the guide (flush with the head). I was thinking that maybe the guides are incorrectly fitted (ie too low), and therefore are preventing me from pushing the seals down as far as they should be. Basically, the 'step' in the valve guide is flush with the head. How should they be installed?

Cheers,
Jeff

The guides have the step so you can't press them in too far.

I once witnessed an apprentice knocking the 7 bells out of the guide fitting tool. When asked what the prob was, he replied " a cannae get it right in".
I had a look & the guide was "home", but he had mushroomed the top of the guide.
He was taken aside & i explained that sherpa van stubs were for anger management, not valve guides.
Sorry went a bit off topic there

When I was having my 4.6 engine built, I asked the Range Rover Engine builder about the valve stem oil seals. He said that they have a tendancy to come off in use, and that nearly every engine that they serviced where such were fitted, they had come off.

He also said that many of the post 1994 10 bolt cylinder heads that they received brand new from Rover never had the valve stem oil seals fitted. It seemed that the factory had stopped fitting them.

Ron.

How about a touch of glue when they go on?

Hi Jeff
Some years ago I bulit a RV8 for a mate of mine and we used Vauxhall CIH valve stem oil seals as we did not have a complete set of Rover ones supplied in the gasket kit.I used some Loctite Threadseal 2701 and to this day the seals are still in place.Whether this is because the seals are'nt the proper ones or whether it was because of the thread seal I don't know but it won't do you any harm to try the thread seal route.
Just make sure that the fluid is completely dry before you fire up again.
Hope this is of some help.
Cheers Paul