Heitmann

iTrader: (1)

Hi there

Could use some help to determine if this could be seal or guide....
I guess seals and guides will smoke in same way...?

It did smoke at times so I knew something was wrong, so removed exhaust manifold to have a look, and looking at cylinder 3 made it quite obvious that something was not right there.
There was also a small trail of oil in the manifold port 3, but just a little bit.

Is it just a matter of trying to put a new seal on that valve and if that doesn't help it must be guide? - or is the picture indicating which of those it most likely can be?

Cylinder 3


The others:


thanks for looking

matthewpickup

i think its a guide thats gone as i think if it was a valve stem seal would it not smoke as you let off the revs ? rather than smoke all the time

Turbo Zetec

iTrader: (1)

cossie guides suffer badly from wear, could even be rings. basically you won't know until you take it apart. you could probably make a tool to change the stem seals on the car, but for the effort, you might aswell take the head off.

AstoN_B

iTrader: (1)

Compression test should give indication as to whether its the rings or not.

Heitmann

iTrader: (1)

Guys thanks for your input

One thought though - I see two valves in the picture, only one covered in oil. To me that means it can only be guide or seal.

And it didn't smoke all the time - symptoms was pointing at seals/guides
I believe the smoke would be pretty much the same if guide or seal ???
But i wondered if the amount of could tell if it was likely to be the one or the other

Thanks again

AstoN_B

iTrader: (1)

Couldn't see at great detail last night as iPad screen was turned down.

Surely if the guide was worn then the seal would still stop oil getting down there?

Sounds more like seal to me but I'm not a cosworth expert.

Heitmann

iTrader: (1)

Thanks Aston

Sounds plausible the way you put it for sure - hadn't looked at it this way before....im no mechanic (obvious I know )

But if the seal is stopping oil from getting to the guide normally, then why do I see these questions about if worn guides is causing oil smoke ?

Not questioning your input in anyway - just wondering this

doga-ot

iTrader: (1)

Bent valve

AstoN_B

iTrader: (1)

I could be way off, my experience is of CVH's.

But the stem seal is there to stop oil running down the valve and limit gas blowing back up. Without seals the oil will simply run down the valve guide since it does so little to stop it happening.

Best if someone with more cosworth experience comments for sure cause I'm speculating.

doga-ot

iTrader: (1)

Either way its a head off jobbie bud best remove and take a gander, I also couldn't see pic properly this morn on phone on underground, I said bent valve now i'm home does look like seal.

WES

Turbo Zetec

iTrader: (1)

could also be a loose guide... it does happen, its rare though. cossies have circlips on top so it shouldn't fall through and do any damage in theory, but deffo worth taking a proper look.

coswurv

iTrader: (8)

I'd say its looks like the valve guide seal on the right hand side valve, it's defo more moist at the bottom of the guide compared to the other, plus being the same cylinder your always going to get it on both valves obviously, if it was worn guides I'd hazard a guess that the other cylinders would be showing sign of wear and by the pictures they seem dry enough. There is a thread on here somewhere of a tool a guy made to change valve guide seals in situe so I'd copy that and change all of them and try that, it may take a while but beats paying for new headgasket, head bolts, fresh oil etc etc

Heitmann

iTrader: (1)

Thanks everyone

I think as the first step I will just change that one seal.
With a little luck that could be all. If it doesn't cure the smoke - then head off.

AstoN_B

iTrader: (1)

I could be way off, my experience is of CVH's.

But the stem seal is there to stop oil running down the valve and limit gas blowing back up. Without seals the oil will simply run down the valve guide since it does so little to stop it happening.

Best if someone with more cosworth experience comments for sure cause I'm speculating.

Heitmann

iTrader: (1)

Thanks - agree on the guides that the others you would think they also would show sign of wear

actually I left out one information - I did change the seals about 4000 miles ago and it has become worse for the last 1-2000 miles. So I could have messed up that one seal when changing. So I have the tools to change it with head in place, so that is what I will try as a start.