compression testing how-to?

[GregCrabb]

I couldn't find a difinitive answer to this question so I'm posting it.
I think I will do a compression test on my truck just for curiosity sake since it has 193,000 miles on it. Do i need to pull all 8 glow plugs to do the test (my old VW rabbit said to take out the 4 injectors so the engine would spin faster) or just remove the one plug at a time to screw in my adapter? Seems to me that only one plug at a time to get real world test results would make more sense. It's not having any issues that I know of, just very difficult to start in the winter if not plugged in, even with the modified glow circuit. Summer, it starts within 2 secs. Thanks

[DmaxMaverick]

Pull all 8 plugs. The starter has a hard enough time as it is. No need to add stress. Be sure the battery is healthy before attempting. The goal is an objective comparison of the compression values. Not so much the values themselves. More critical is the block temp and cranking duration. The engine should be hot, and crank 6 puffs for each sampling. DO NOT add oil, like you might with a gasser (disaster waiting to happen!).

Enjoy, and good luck.

[GregCrabb]

Thanks, will do next stretch off. I'd heard about not adding oil from my VW rabbit days.