[flyingspirit55]

Hello all, new owner and new to this car. Car runs rough. Car had misfire #6 and random misfire codes on all cylinders except #2, did the usual stuff first, coils, injectors and plugs etc. has 200k miles. Don’t know any of the history. Always ran rough. Like a bucket of bolts. Goes into limp mode as well.

Checked compression, the numbers:
1-180psi
2-175 psi
3-170 psi
4-180 psi
5-150 psi
6-90 psi

Pulled the valve cover and it’s hard to tell since the cam covers don’t give much access to the rockers but the #6 exhaust side rockers feel real loose unlike #1. Like 2mm of play.

Also has blue smoke but wasn’t doing that until I changed the oil, possible overfill by half a quart. Smoke no consistent. It Does backfire as well.

So what could cause this? Collapsed lifter? Bent valves? Worn piston rings? Stretched timing chain?

Deciding wether to pull the head or just the cams?

Some direction please.

[flyingspirit55]

Also, I believe I have ruled out the injector seal on #6 by switching out some injectors.

The low compression between #5 and #6 maybe a blown head gasket but I haven’t seen any over-heating issues. Could a blown head gasket cause all this? Burnt valves?