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Hey guys, i'm a little confused with some of the info i am getting about this... I have a 4cyl, 1.6L DOHC and i am puffing some smoke on start up, so i want to replace the valve seals. What i am confused about it, do i actually have to take the head off of my engine for this, like the dealer says? or can i just do it with the head on? Thanks!

Depends on the engine.. the 1.6L DOHC valve spring retaining clips would be very hard to remove with the head still on the engine.. I am not saying it cant be done.. but it would be VERY difficult and require some specialized tools to do so. You would also need an air compressor on hand to pressurize the cylinder (via the spark plug hole.. 15psi should do the job) so that the valve doesnt drop back down into the cylinder once the retainer clips are removed. You dont want to use too much air pressure since that will just cause the bottom end to spin.. but honestly.. the valve seals are under the valve springs which are held on by the retainer clips which are under the HLA's (lifters) which are of course under the cams.. and are recessed down into the head a bit.. So while I am sure its probably possible.. its definately a LOT easier to remove the head and do the job on a bench. Oh and getting the valve seal off while the valve stem is still in place would probably require some sort of slide hammer rigging.

Now there are indeed engines where you can do this job far easier without removing the head than the DOHC 1.6 allows. Thats why it should be noted that this answer should be applied only to the DOHC 1.6 engine. One last note.. when installing your new valve seals make sure to use the supplied nylon sleeve over the tip of the valve stem.. this will prevent the valve stem from accidentally ripping the inside of the new valve seal as you slide it down over the edge of the valve stem. If your kit of parts did not include such a sleeve (most do but not all kits include this) you can use a straw from McDonalds or Jack in the Box and just cut off a portion to cover the valve stem. Hope this helps.

Tunes67

One more thing.. assuming you do the job on the bench.. before you remove the retaining clips.. use a scribe or sharpie to make a mark across each valve face and the bottom of the head. This will allow you to ensure that you are putting the valve back into the same position that it was in to begin with (this will help keep it seating properly). Also do one valve at a time.. this way you are sure to put back each valve in its original location. If you find valve damage to the point where they have to be replaced.. make sure you get a grind job done on the head as well.

Tunes67