Well, I got the dreaded misfire codes. Spark plug tube 3 was full of oil so I replaced all my plugs, tube seals, and valve cover gasket. I still feel a miss at idle. So I ran a compression test. Results are as follows
1 - 80psi
2 - 150psi
3 - 70psi
4 - 140psi
I find it odd that the paired cylinders are reunning within 10% of each other. Maybe a timing issue? The previous owner took horrible care of this car as I'm learning

 

Those don't look good. A healthy cylinder should be >200psi; as a reference my 04 w/26k miles was within 4 psi of factory new spec on all cylinders (240psi).

Have you checked the coolant for contamination to rule out a blown head gasket? Given how bad those numbers are, I'd do a leak down test before speculating.

 

I'm planning on doing a leak down over the weekend.

 

Leak down test it but something is WAY off. Typically you're looking for consistency between each and to be around 180-240.

 

That's what I'm saying. It doesn't make sense that its THAT low but is still running. I work for toyota but idk anything about these engines

 

I messed up on my compression test because I didn't open the throttle body. New results:
1- 140
2- 200
3- 200
4- 80
Did a leak down and 1 was coming out of the throttle body. Did a leak down on 4 and it came out of cylinder 1. I'm stumped. No bubbles in the radiator, no air from the dipstick tube or oil cap. I don't have a clue

 

The only thing logical answer I could come up with is valve train. I don't think a valve is closing all the way on cylinder 4.

 

Do a leak down test. my s ran 190 all 4 cylinders but I'm a mile high here in Colorado and temp affects the numbers. My thoughts are your rings are getting a little toasted... But i could be wrong so leak down and know for sure before putting anymore money into the car.

 

I would strongly suggest you check your valve and ensure they're within spec. Maybe they weren't done at 100K. Easy and cheap.

 

He already did the leak down....