1997 S90 with DOHC Timing Mark
JBrown » 1997 s90 with DOHC.. nonturbo… I am doing valve repairs after a broke timing belt. while I have the head off I can see that the timing mark on the crank dose not have the number one piston at TDC. it’s really about half way down in the cylinder. is this the way it sould be for cam timing?
billofdurham » The piston may not be on the compression stroke so you need to get it to that point.
Remove all the spark plugs.
Stick your thumb OVER the #1 cylinder spark plug hole. Rotate the engine until you feel pressure on your thumb. That’s the compression stroke and TDC is at the top of this stroke. The timing marks should now be aligned.
DanR » When the crank is on it’s mark, the piston is not at TDC, since it is an interference engine, the mark lowers all pistons so the valve cams can be rotated without hitting any pistons.
Last Updated on August 19, 2020
