? Valve guide stem seal issue?

[Taavinen]

Hey all. I have started to an odd puff of oil smoke on start up So i am assuming that my valve guide stem seals might be leaking. - though it was a bit odd, two cylinders appeared to have oil fouled plugs, then i took it for a 20 mile ride and checked after and no wet oil look on any plugs - maybe it seaps down overnight when a valve is open?

Would these get quite hard and brittle over time without much use? (1992 vmax with 14000km, probably sat for many years).

Besides getting into the top end being a PITA, how straight forward is it to changes the seals? And how expensive are they? I assume you would do similar as with a car and pressurise each cylinder as you decompress and remove the spring, collet and retainer to stop the valve from dropping into the cylinder.

Don't have a compression tester. I smelt the oil and does not seem to smell like fuel at all.

Cheers for all your help guys, i am trying to get thru all these teething issues

 

[MaxMidnight]

Changing the seals is strait forward - more time consuming.

Before tearing the motor apart are you sure it is necessary? I guess that if you have started to use more oil the the answer is yes. However, if it is just a puff as you start then perhaps you don't need to intervene just yet.
It may also be worthwhile getting someone to follow you and see what is coming out of the exhaust on acceleration and over-run.

If you do decide to go ahead you will need the following:

1 x Coolant drain plug washer
4 x Header O rings
2 x Head gaskets
16 x Valve stem oil seals
2 x Cam cover gaskets (you may be able to get away without these but don't be surprised if they leak!)

In addition to all the usual spanners you will also need:

Torque wrench
32mm socket (to rotate the motor when re-timing the cams)
Valve spring compressor
An old 35mm film canister (to make a shield to protect the valve bucket bores when removing and replacing the valves).
The Yameringha special tool to hold down the buckets when changing valve shims (Unless you are an extremely lucky person and they are all within spec!)
Feeler gages
A spanner to rotate the cams and to stop them from turning when replacing the cam caps - can't recall the size.
A long Allan key for your socket set to remove and re-torque the head bolts.

I think that is all but I'm sure other will chip in if I have missed anything.

 

[Taavinen]

Hi MM. Thanks for the input! I had my wife follow me yesterday. It was only once, but after heavy acceleration, when i would drop the revs, she saw smoke puff of 'grey smoke' out of one side. Otherwise there was no smoke. I will keep an eye on it for a few dyas and see how it goes

 

[MaxMidnight]

Sounds like stem seals will need doin' but if you're not using muck oil...

One other small, teeny, weeny matter that I forgot mention was that whilst (I am told) you can get the rear head off in situ, you can't with the front.

I have read that if you can remove the studs first then it will come out. When I removed the studs from my motor they were in 'kin tight! Wouldn't fancy trying to get them out twixt head and block with some Mole wrenches.

So, you are probably faced with removing the lump from the frame.

You can read how to do this in my article 'Fifty Seven ways to get a Hernia'. :rofl_200:

 

[Taavinen]

LOL. Not sure what you mean by 'muck oil' as in oil that needs changing?
Spoke with my mechanic about it. He stated the heads would have to come off, but it seemed to me like he was talking about doing it with the block still in the frame??

 

[rhoke]

Yes it can be done in the frame. IT IS A PITA THOUGH. The valve seal part is easy. Its getting to them that sucks.

Its a day job, if you have done it before, otherwise at least two days.


I had the same issue with smoke but, mine what worse than you state. Valve seals fixed the smoke problem. Got the ebay viton seals and they work great.

Roy