Ya I should do the test I'm almost 100% sure the drivers side is ok but I'm a little worried about the passenger side. What do you do to do the test? I'm pretty sure I have the old style because I would need new coils and plugs if I went to the ford heads.
If you haven't changed your heads, and your car is an 07, you have the old style heads. Even if you didn't, it's just a matter of getting the right adapter for the compression test kit (which you can rent from AutoZone/Advance/O'Reillys). The kits just don't come with either the 16mm (old style) or 18mm (new style) adapter.
So if you want to borrow my kit, it has everything you need. Everyone seems to have their own unique way of doing a compression test, which is highly dependent on
why you're doing it (to check cam timing, to check for proper valve operation, to check piston health/ring wear, etc...). Here's how you do it:
- Remove the fuel pump fuse/relay so the fuel pump doesn't run
- Fully depress gas pedal and crank the engine for a few seconds, to clear any fuel out of the engine
- Remove the COPs and all 8 spark plugs
- Starting at cylinder 1 screw in the gauge hose with the correct adapter (it has a push button to relieve pressure... I'm OCD, so I always press it a few times before I take a reading)
- Get in the car and crank the starter, with the pedal
fully depressed for a set count (4-5 seconds is good... just keep it consistent).
- Go out, read the gauge, and write down the reading for that cylinder
Normally, you would do all eight cylinders, but like I said, you can just pick a cylinder from each side and make sure they're close. At our altitude, you should get a reading of between 130-140psi if your engine is stock (9.8:1 CR).
If your cam is off on one or both sides, that number will be really low. In my case, I was only getting 90psi on all eight cylinders. Turned out the crank gear had somehow moved on me, which affected both banks.
Also I went out and started it today. It seems as the check engine light would come on after every other start. Started it up it came on. Shut off cleared code ran fine. Shut it down and restart came on. Shut it down and cleared and start no code. I read a thread that said when you change cam sensors the car needs to run for about 20 min for ECM to readjust.
Mine ran pretty well, considering. I took it on a test drive, and it built boost and everything. We actually went out to eat, and on the way back, it just didn't feel like it had the low-end oomph it should have. I started datalogging and noticed my fuel trims were all over the place. That's when I decided to do a compression test and found the cams were off.
As for running it for 20 minutes, I've never had to do that. It may be some archaic step in the FSM, but I really doubt that's why you'd see a code. I could be wrong, though....