Cadillac Repair: compression test kits, o reilly auto parts, sears store

Question
We need to run a compression test on our 1989 Cadillac DeVille. Though we have a compression test kit from Harbor Frieght the fittings are not the right size. When we called we were advised that they do not offer other fittings. Is there a specific compression test kit that you know of that works on this vehicle?

Answer
Hi Liz,

     If you go to snap-on, mac, cornwell or matco websites they all have testers that will work. If you call your mechanic they will say what tool truck visits their shop and you could buy it from the toolperson. The downfall is that the tester could cost $300 or more.

     If you go to your Sears store they have one for $59.99  tool number 00947089000 that as several differant adapter hoses and fittings so the tool will work on many differant engines includeing lawnmowers and motorcycles if you need to check that also. Basically you want the screw-in end to look like the sparkplug threaded end. If the plug in your engine has threads on the plug that are aprox. 3/4" long. You can screw in an adapter that has 1/2" of thread and be ok. But if your plug has threads 1/2" you can't use the adapter that is 3/4" long or it might interfere/touch the piston and damage something. Hope that makes sense.

     If this is a 1 time thing and you don't plan to test compression on any other engines then auto zone, o'reilly auto parts and pep boys have free loaner tools. What you do is leave a deposit or pay for the tool and when you return it in good condition they give the deposit back.

     Hopefully that helps find a tester. Bill