Is #8 cylinder the closest to the throttle body? If so, the other cylinders are gonna flow differently especially with hyundai pcv system. The 5.0 might just be more prone to gunk up the fwd cylinders. A lot of folks go catch cans on these GDI engines for this reason.
Not trying to create more issues, but sometimes an extremely clean cylinder is that way from a slight water leak into the cylinder? Easiest way to check for that is with a coolant pressure checker. You could often borrow them from an auto parts store.
Stupid question of the day... Is it cool to do a compression test with the intake manifold, all plugs removed? Fortunately my tester fits but last time I used it was about 10 years ago on my bikes. I've never tested a car before.
Yes. Ground out the plugs or if this has coils on each plug I’m not sure but if you can just disconnect the coils that maybe all you need to do
Yep, disconnect all coils and normally the other plugs would be installed. 1 at a time and turn the engine over about 3 to 5 seconds
Plugs, coils and intake are all removed. Should I install the plugs or just "send it" as is.? Thanks for your help guys
There would be a noticable loss of coolant and usually runs hot. He hasn't mentioned anything like that yet
True, but I don’t think he has driven it enough to know. Hopefully it is not coolant related. I’ve seen forklifts with small coolant leaks (burning during combustion) that run for a few days between water fill ups.
I don't see any way coolant has access to the intake manifold or upper side of the valves. I have driven the several hundred miles, coolant level seems stable. I've replaced intakes on 300k+ Town Cars twice as the thermostat housing is built into the manifold and prone to leaking. I replaced them with Dorman intakes which apparently are of a better design.
Yep, your compression looks real good. So your gonna replace the MAP sensor, new plugs and coil then run the intake cleaner through?
I goofed around this morning fabbing a block/plate (wood) to attach with the OEM manifold bolts, over each intake. I picked up fine walnut shell, hopper and gun to clean out the intake ports with my compressor. That only cost me $80 @ HF. I'm nervous as fook to attempt this because I don't know exactly when the valves are fully seated. They're so grimy it's hard to see. Guess I could scrape the loose/wet oily gunk while simultaneously vacuuming out the particles. Or fook it, replace the parts ya mentioned and run the cleaner. Remove the manifold after running the car for a while verify the cleaner actually works. Removing the manifold is pretty simple. 8 bolts a few vacuum lines and 4 bolts for the throttle plate gizmo.
Man those things look gunked up. Whatever you decide...walnut or cleaner make sure you change the oil immediately afterwards