>Wally, by degreeing the engine, do you mean putting the dial indicator in the spark plug hole to find true TDC? Or are you talking about cam timing. I did have the strange floating vibration damper syndrome on my Volvo. I could not get it legally smogged because the guy could not check the timing, even though the timing was correct.


I would just try to find TDC. Take an old plug, knock the insulator out, and put a 6" carriage bolt in, with the head protruding into the cylinder. Make sure that the head will go thru the plug hole easily.

Pull #1 plug, screw the positive stop into the plug hole. Carefully and slowly turn the crank backwards until the piston hits the stop - you want to hit gently. (It is not usually a good idea to turn the engine backwards, but IF THE BELT TENSION IS CORRECT, there should not be a problem.) Use a scribe or razor knife to accurately mark the dampener at the timing pointer.
Rotate the engine in the proper direction until you again gently hit the positive stop. Again mark the dampener at the timing pointer. Remove the positive stop.
TDC is exactly halfway between the two marks. It should agree with your existing TDC or 0 mark. If not, your ignition timing and cam timing may well be off.


Reinstall the plug.

Wally Plumley
928 Specialists


The positive stop method is the most accurate. It is very, very difficult to get TDC with a dial indicator with any real precision - you would probably be lucky to get within three degrees. To get that close, you would have to estimate where the gauge stopped moving up and started moving down - and those points are several degrees apart.

If that doesn't seem reasonable, just think about degrees of rotation versus thousandths of linear movement. At five inches down in the cylinder, a few degrees of rotation make a LOT of thousandths of movement. Right at TDC, a few degrees of rotation make essentially no linear movement.