Replacing valve stem guides

Rob H

Rob H

Member +
It's a specialist job changing the guides it needs to be done by a machine shop. But if you mean the seals they can be done quite easy.
 
M

mork

Member +
Seals have been done but it still smokes when warm after pulling away from idle. Turbo has been rebuilt, but only with one of the eBay kits.
 
M

mork

Member +
Ok. Cheers guys. Out of interest, at what mileage do you think it's worth thinking about doing the guides?
 
Rob H

Rob H

Member +
Never had to do any not something that normaly wears out. The oil has to be getting passed the seals for it to cause smoke anyway. I don't think the guides will be your problem. I would be looking at the seals or the turbo again.
 
Texx

Texx

Super Moderator
If the valve stem to guide clearance is excessive then a new set of valve stem oil seals won't be able to seal sufficiently. An excessive guide clearance will allow the valve to move out of position slightly as it is opened and in doing so the stem seal will deform, instead of the seal scraping the oil off the valve stem as the valve opens it allows some of the oil to remain on the stem, this oil is then scraped off by the stem seal as the valve closes, the oil then runs down to the valve head and then either into the combustion chamber (if it's an inlet valve) or out of the exhaust (if it's an exhaust valve).

Replacing the valve guides is not something I would say is very common, however from experience the previous two 4E cylinder heads I've rebuilt have required new exhaust valve guides.
 
T

turbok79

Member +
I had new exhaust guides fitted when I had my head rebuild. I couldn't be assed to change them my self. Iv done loads when I worked at an engine shop. You have to warm the head up and knock them out using a drift. Same thing to fit the new ones then run a reamer down the. The guides are the same a ford zetec funny enough
 
Texx

Texx

Super Moderator
valveguidecheck.png
 
You must log in or register to reply here.
Top