P0302 and P0307
Asked by Edward Jan 05, 2019 at 10:28 PM about the 2003 GMC Yukon XL Denali 4WD
Question type: Maintenance & Repair
03 GMC Denali 6.0L. Had the first code P0302 that
wasnt bad, the engine light would even shut off at
times. Had a heavy foot one day and ran up to 4k
rpm and now its throwing P0307. Shop is telling
me its valve train, $1500. The truck has 230k and
has little noise when cold start. Revving the engine
while in park it sounds good with no noise. I dont
have the money to replace this and that. Does
anyone have an idea of what to try to fix first?
4 Answers
You have bad lifter. .and I hope just lefter because if camshaft collapse you need engine work...
It still runs and drives good... Could I just replace all the lifters and be ok or should I replace rods as well? If they are bent they would need to be. Is there somewhere recommended to buy a full set of lifters?
My frend the misfire people they check it and they replace every thing you know ...spark,coil,check the connector but ...there is common problem with gm...if tow piston not working properly that means not all the rods and lifter are bend or stuck ..
Fixed it! Kept thinking about the #2 and #7 cylinder how they are on the ends of the fuel rail... So I checked the fuel pressure regulator and found a tear in the rubber! Soon as I fixed that vacuum line the engine lights where gone and its running 100%
