1995 Other Isuzu Models Compress Test - 1 cylinder at less p

GREY GHOST

MEMBER
1995 ISUZU
4 CYL
2WD
MANUAL
110,000 MILES

One of the spark plugs blew out on the engine with a loud bang. No threads left. Mechanic put "adapter" of sorts to place it securely back in. Its secure for sure. It runs just fine now. However, he did a compression test, and one cylinder is at 25 or 40 points below the others. I cant tell by driving it, as it runs pretty smooth. Is this engine headed for death with this "lesser" cylinder or would it possibly just keep running well indefinitely? I've driven it for like a month now as is. Thanks for any help.

1 Reply

MHPAUTOS

MECHANIC
31,937 POSTS

Hi there,

You will need to know where the compression is being lost, this can be done with a wet and dry comp test, with a small amount of oil in the cylinder the comp is tested and as the oil will seal the rings, if the comp stays low it will be a valve problem if comps are up it will be a ring problem, if valves they will slowly continue to burn out and a miss fire will start and rough running and power loss will begin, so get this simple test done first.

Mark (mhpautos)