Bought a 2025 yukon denali and have had it in shop multiple times. First intake manifold gasket then a lifter failure. Am telling them to replace coil and plug because they can't seem to fix the cylinder 4 from missfiring. What else would cause this? Computer, loose wire?
Cylinder 4 miss-fire P0304
- Thread starter steepz
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
blanchard7684
Senior Member
- Joined
- Dec 23, 2024
- Posts
- 247
- Reaction score
- 132
Fuel injector, spark plug, or plug wire, then past that it could be a wiring/connection issue.
Hopefully not any cylinder head issue: head gasket, valve, valve guide.
Bent pushrods can cause it also but I would think they would have checked this with the lifter replacement.
Hopefully not any cylinder head issue: head gasket, valve, valve guide.
Bent pushrods can cause it also but I would think they would have checked this with the lifter replacement.
viven44
Full Access Member
When you say shop, you mean dealership right?
Also what engine ? Assuming 6.2L as its a Denali -- Adding some details to your signature would prevent this question.
Also what engine ? Assuming 6.2L as its a Denali -- Adding some details to your signature would prevent this question.
viven44
Full Access Member
I wouldn't be surprised if is the same underlying problem on that 6.2L with all that is going on with 6.2Ls these day on the 21-24 year models... GM thinks the 2025s are safe, but who knows.
How many miles on your 2025?
What lifter failed? #4 cylinder?
To replace a lifter, the cylinder head needs to be removed, so anything is possible.
I would want the spark plug replaced, because it is easy and the porcelain can often be cracked and cause misfiring.
Has the dealer done compression check on the #4 cylinder?
It is possible a cam lobe for #4 cylinder could be damaged as well.
But the dealer should be able to determine if the problem is ignition, fuel or mechanical.
What lifter failed? #4 cylinder?
To replace a lifter, the cylinder head needs to be removed, so anything is possible.
I would want the spark plug replaced, because it is easy and the porcelain can often be cracked and cause misfiring.
Has the dealer done compression check on the #4 cylinder?
It is possible a cam lobe for #4 cylinder could be damaged as well.
But the dealer should be able to determine if the problem is ignition, fuel or mechanical.
While I wait for a specialist to look at vehicle from GMC corp, I talked dealership into replacing plug and coil and have had the vehicle for a few days now with no issues. Fingers crossed all is well but I will still bring it back in once i hear the GMC specialist is onsite and from what i am being told can perform a deeper analysis of the OBD
Similar threads
