Cadillac Repair Questions? Ask a Mechanic for Answers ASAP
Hi there, I am Cam. Can I get your first name please?With your truck, did you happen to do a cylinder leakage? I am wondering is there is even a slight chance the valve hit the piston and is slightly bent. Even the slightest bend or issue sealing will cause a misfire at lower RPM. To answer one part, no the compression test will not fully check the sealing of the cylinder. The leakage test will evaluate the piston rings and valves. The tool puts lower pressure compressed air in and then when setup the gauge shows a percentage. More than 25% is excessive and would indicate issues with valve or rings.