Smokey Downshift

[hanceformer 0]

Hi all hope someone can shed some light on this problem. I have a 406 turbo 2.0 8v in my 205. Just done a head gasket and cam belt. Runs great and feels just as fast if not faster than before but when I shift down hard blue smoke comes from the exhaust. Any suggestions greatly appreciated as always.

[rallysteve 22]

I would guess that if it only does it during hard downshifts then it is your valve stem seals. If it does it under acceleration then i would think maybe turbo seals. Does it smoke when you first turn the key?

 

Steve

[hanceformer 0]

Thanx steve. No not that I've noticed. It's only shiftig down not on idle or throttle. Could the engine be breathing?

[Pugs in Pieces 0]

does sound like valve stem seals, were they replaced with the head gasket etc?

[hanceformer 0]

No they weren't replaced sadly. Could it be something I could leave until it gets undrivable or could that have a catastrophic result on the engine? Thanx again.

[Pugs in Pieces 0]

it depends what you call undriveable.................

[hanceformer 0]

So smokey u can't drive it. Do u know if it's possible to change the valve stem seals without taking the head off? Thanx.

[Anthony 1,003]

Generally speaking, valve stem seals just get smokier and smokier as they get worse, but never really to the point you can't drive it.

 

The worse they get, the more you'll need to keep topping up the oil as you can get through a surprising amount.

 

It is possible to do the valve stem seals with the head on, but it's alot of faffing around in my opinion and certainly I've always just ended up removing the head - if nothing else, typically I tend to find that if it's done enough miles that the valve stem seals are worn and smoking, then chances are that the guides need checking and the valve seats will benefit from getting recut / lapped in which both need the head off.

[hanceformer 0]

I wonder if it's just as much faffing about to take the cam off and do it from above than it is getting the head off again. Would save me a new gasket set and also stripping the engine dropping it on a jack and moving it all forward to get to the manifold bolts. Hmm dilemma. Thanx for ur input Ant much appreciated my friend.

[smithy 1]

Doing it in situ is a pain in the arse in my opinion used to do it years ago when was apprentice at pug dealer.

On my own car I would certainly have head off and do it properly,by re lapping valves and shimming the top end etc.

[hanceformer 0]

ok thanx smithy