Trailblazer Compression Problem

[Fmcclure]

I have a 03 tb it ran fine then set for a few months now runs ruff scand it p3005 came up changed plugs and coils still ruff did compression test and #5 had only 30 psi all others had 175.Does anyone no how to fix without rebuilding.

[carriedi]

you should call around and see if there is a shop in your area or check with a tool place for the tool to do a cylinder leak down test. Do the test on the cylinder in question and see where the compression is going. see if it is a valve problem or a ring and piston problem and then go from there