Hi All, I think I need to do mine - my mechanic said that the car is burning oil and that the seals may need doing. Is this a difficult job, and can it be done without taking the head off? Cheers!
It could be done with the head on, you would have to connect an air compressor up to spark plug hole to keep the valves from dropping, then the hard part would be to remove the follower, and then even harder to compress the spring as theres nothing on the other side that you can use a valve spring compressor on. It might just be worth while to pop the head of and give it a good service while your at it, cam belt, head gasket, head bolts, check the bores etc. Then while it's of do the stem seals and check the head over.
Is he sure that the rings arent on the way out? You can usually cant tell if the rings are on the way out by running at high RPM and see if it smokes or do a compression test. For valves stem seals it will smoke on start up (when stood for a while) or on over-run when you lift off and re-apply the throttle (puff out a bit of smoke)
I am sure the rings are OK. High RPM is no problem - it is moreso when the car has been standing for a while.
I was reading something on the Pug 205 forum where they put a load of string into the cylinder through the spark plug hole and compressed the string using the piston. That way the valve doesn't make contact with the piston and you can compress the valve springs against the string, remove the collets and replace the oil seals in-situ. Not sure of the valve design on the Pug so don't know if it's possible to do this on a 16v but thought it might be worth mentioning.
would have thought that was unecessary effort, spark plug fitting for a compressor or even a home made tube run off your spare tyre will keep the valve from dropping. Keep the respective piston at TDC to make sure you don't lose it by accident. "you can compress the valve springs against the string" The springs don't push down on the valve without the collets. You can buy valve spring compressing tools that only work with head in situ, just a big lever. For the effort involved I would always take the head off. Take the whole lot off at once, inlet exhaust, downpipe etc, easier stripping them once off.
I've used this method before on all sorts of different engines, just make sure you remember to only do 2 cylinders at any one time, then remove string and bring the other 2 pistons to TDC and do those.
i have tryed this in situ and failed, top of valves are deep set , and its real awkward, the exhaust guieds will be ucked any how . take the head off and servise it properly ,
I've done it plenty of times and it's worked fine - but it's easier to take the head off as long as you give all the rusty bolts a good dose of penetrating oil (Plus Gas, etc.) every night for a few days beforehand. You can also use windscreen washer piping to pack out the combustion chamber. But as has been said, it's always going to be a better job if you take the head off and do it the "right" way!
Also taking head off will let you see if you have any other issues other than valve stem seals. ie.worn bores,valve guides etc.
As mentioned above Usually the guides are fecked on the 16v heads, so just fitting seals might not cure it 100%...
