UkLegacyT

as title, the lower camshaft seal on the r/hand head popped out about 2 weeks ago, allowing oil to run onto the heatsheild and set alight.
so, i bought a new seal from subaru and fitted it, fitted perfect and was a really tight fit as it should be.

however, driving home tonight, smoke in rear view mirror so got home asap hose at the ready and the heatsheild is smoking and covered in oil, seal has popped out again!

thankfully on both occasions the only thing to be set alight is the heatsheild and nothing else.....but....this is getting a p1ss take now, the car could go up in flames if it happens again

i have built many engines and fitted numerous seals, so its not like ive fitted it wrong, and the one that originally popped out is visibly undamaged.

therefore, what is causing this to happen?

am i correct in think the cylinder head breather may be blocked and hence pressurising the head and popping out the seal?

any advice appreciated
ian

tweenierob

You have probably tried this but as a start.......
Is the cap that holds the seal in deffo tight??

When you push the seal in, is it tight?? Ie.socket needed to tap it in (tech speak that is)??

Rob.

ustolemyname??stevieturbo

iTrader: (1)

I cant remember exactly what it looks like in there, but the oil seal will be to stop oil from the cam bearing getting out. Is there a small drain hole? that allows the oil to drain after it exits the bearing?? The oil the seal sees should not be under pressure, but if the drain back into the head was restricted, it could be, forcing it out??
Did you use any sealer?? could a bit be blocking any drain hole??
Just a thought....

scoobyslut

When you fit the seal do you "release" the bearing cap first or simply "ram" the seal in?
I would release the cap, slip in the seal, then re tighten the cap down to correct torque setting.
You may have an "issue" with pressurisation, but it would be pushing other seals out as well, not only that but the breather system would also show signs of activity.
the first seal may of failed due to heat/ age, the rest sounds as though down to incorrect fitment [sorry!]

Pavlo

Most Nitrile rubber seals will vulcanise themselves into place if you fit them 100% dry, sliding them in can sometimes help. But would agree with steve, check the diagonal oil hole that leads from the seal end-cap area.

Paul

UkLegacyT

thanks for the ideas

i havent used any sealer, i fitted the seal dry, but just smeared some fresh oil on the inner lip ie the part of the seal that the cam rotates against.

the seal was a very tight fit, not enough to distort it or damage it in anyway though.

i didnt release the cam bearing as i fitted the seal with the engine in place, and to get to the cam bearing bolts would have meant removing the rocker cover.

the first seal that popped out has only been in about 6000miles ish, as this is when i rebuild the engine and fitted all new gaskets/seals.

its just bugging me that its the seal from the same place come out twice, therefore i would agree that the drain back hole needs looking at.

the seal is also fitted flush to the head as it should be, so will not be causing any blockage to the drain hole itself.

i am going to take the engine out this week as i am returning the car back to standard, so will be swapping bottom end/exhaust/gearbox and rear diff etc.
therefore i will have a good look at the head when it is off.

at least i have a few ideas now what to check.

thanks, ian

p.s. will let you know what i find, cheers.

Tony Shipton

Did you find out what was causing it? - I have the same problem...