So my 07 G35 coupe was turbod at 44k and is currently at 46k miles. Ever since it came out of the shop it has had numerous problems and no mechanic can figure out what's truly wrong. The following are my issues.

-Codes P0300 and P1078.
-Idle jumps from 800-1400 rpms and never stays steady.
-AFR jumps from 13-17 constantly.
-Low oil pressure around 10 psi when car has been running for 20 minutes at 800 rpm.

I've had a compression test, leak down test, check spark plugs and everything checked out fine. Had bank sensors replaced and issue never resolved as well as the intake valve cover solenoid. Now they're saying I may have a blown head gasket. My car doesn't overheat, blow white smoke, or have any funky smell and I've been driving the car for over 2k miles. They indicated that it maybe that since I have milky oil at the bottom of my cap and little oil in my coolant tank and radiator.

They also may think the issue is occurring due to a faulty GT MAF or bad tune. Had Church do the tune with Osiris.

Anyone ever had similar issues or know what could truly be going on?

Also do you think if I go back to NA, the issues would resolve?

 

if your oil is contaminated with coolant, you can be doing some serious damage to your motor. At any case, you are looking at some serious repairs to your engine. I doubt at this point removing the turbo system will fix your problems.

 

milky oil under the cap is not as big a deal as oil in the reserve tank, but they are together they are sure signs that you, indeed, have a blown head gasket.