Why have you ruled out the coil being the problem? I would retorque the intake in the proper sequence. The engineers who designed the engine knew what they were doing. Plastic flexes a lot.
No cause when the coil code comes up that's when I change them.
This is wrong for anyone who likes their car. First off, the PCM is really only guessing which cylinder is misfiring. Second off, the coils begin failing long before the first CEL comes on. Replacing them one at a time usually means you're running on at least one marginal coil all the time. This kills your cats.
Does anyone know if these are interference motor?
I don't think you quite understand the difference between interference and non-interference. An interference motor's piston at it's highest point enters the path of the valve(s) when the valve is at it's lowest point. Normally, the valves move up (close) when the piston is at the top, so there's no problem. If the valves get stuck or the camshaft stops turning and the valves are down/open, the piston will smash them when it comes up. That's the interference. A non-interference motor can have the pistons and valves in any position without risk of collision.
Point is, interference or not, having a foreign object in the cylinder will do roughly the same amount of damage.
When I first started the car I heard a couple of knocks then it went away I had low oil but if I did drop something inside could it had messed things up? Anyone have a quick how to do the compression test on these? Thanks
Low oil... knocking... fun. I know. I spun a bearing with low oil and a hard turn. I could have gotten thicker bearings from a Jaguar site, but if the crank and rod were damaged too much, the bearing wouldn't help and you can't get replacement cranks/rods. So I played it "safe" and just got a used junkyard motor.
I checked for the spun bearing with a screwdriver, straw with tick marks, and a ratchet to turn the crank. Remove all spark plugs. Place the straw in cylinder 1 and turn the crank until it reaches TDC. As you pass that cylinder's TDC, the straw should smoothly move back in. If you have a spun bearing, then the straw would have a delay at TDC and
then move. Do this for the next cylinder in the firing order. When you think you found the spun bearing, stick the screwdriver in the hole and push the piston. If the bearing is shot, the piston will move when you push it.
For the compression test all you do is pull the spark plugs, attach the tester to the spark plug hole and turn the engine. Then you read the gauge. It only checks the cylinders for leaks, not for vacuum leaks upstream of the heads.
