2013~2016 Compression Test Results?

[Austin_Mull]

My wife’s CX-5 threw a cylinder 4 misfire code on her way home from work and she had to drive it home in limp mode. Knowing it’s high mileage (264,000) and she poorly maintained it (I’ve come home from overseas to find it bone dry on oil multiple times) I figured I’d run a compression test before even bothering to try other causes. We’d already decided that we weren’t going to sink money into significant repairs anymore since she wants a new car. Anyways, I ran the test and I don’t really know what to make of the results. Cylinder 4 is the lowest by far, and the numbers get higher as you get further away. This would suggest a warped head right? I’m not sure if I’d consider this a compression issue though. Cylinder 4 is a little more than 10% variation , but barely. I wouldn’t consider this drastic. Anyone have any thoughts on if this is a compression issue and if it’s worth diagnosing the misfire?


*This was a warm test

 

[ruthrj]

Signs of a Blown Head Gasket Here is a very similar thread, but their cylinder 4 numbers are much much lower. I’d give this a read for suggestions and troubleshooting. They’re digging in and trying to fix the engine but from the sound of it, doesn’t sound like it’s worth the trouble for you if your wife isn’t keeping up with maintenance and wants a new car.

Cheap and quick items to check would be spark plugs (when were they last replaced, look fouled at all?). Could be the gaskets suggested. May be that simple as your compression numbers aren’t too bad. They look to be near nominal to my admittedly untrained eye. Other numbers I’ve seen were 130-150 but maybe that’s cold vs your warm test? Guessing cheap gas is being used too if oil levels haven’t been checked, fuel injectors could be fouled.