Check engine light flashing - Cylinder 6 low compression

[Roach011]

Bronco is currently at the dealer waiting to be further evaluated by Ford. My favorite independent shop already ran a few test and ruled out plugs and coils for the misfire codes. They did the compression test and verified low compression on C6. Anyone else have experience here?

fwiw - called ford customer care and they comped me an additional 36k mile premium care. That's nice.

2023 WT 52500 miles 2.7

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[Ducati1098]

Bronco is currently at the dealer waiting to be further evaluated by Ford. My favorite independent shop already ran a few test and ruled out plugs and coils for the misfire codes. They did the compression test and verified low compression on C6. Anyone else have experience here?

fwiw - called ford customer care and they comped me an additional 36k mile premium care. That's nice.

2023 WT 52500 miles 2.7

Could be a number of different things, even if it is compression related. I’d be surprised if it is, but let the dealer do their diagnosis and see what they say

 

[BudgetBronco]

I clicked and hoped maybe it could be a loose plug, but apparently not the case. Was it running poorly? I will watch this thread, please post an update when you have one

 

[Roach011]

I clicked and hoped maybe it could be a loose plug, but apparently not the case. Was it running poorly? I will watch this thread, please post an update when you have one

it was, shaking and unstable. For sure.

 

[Roach011]

Could be a number of different things, even if it is compression related. I’d be surprised if it is, but let the dealer do their diagnosis and see what they say

Burned valve for sure, dealer still checking a few other things. Likely needs a new head but will potentially receive a new motor. Dealer is supposed to call me back this afternoon with a full "plan"

 

[Ducati1098]

Burned valve for sure, dealer still checking a few other things. Likely needs a new head but will potentially receive a new motor. Dealer is supposed to call me back this afternoon with a full "plan"

Wow, that's very interesting. Id love to know how it burned a valve. Cant say I've ever seen one do that before.
Glad to hear they hopefully have it figured out though.

 

[Roach011]

Wow, that's very interesting. Id love to know how it burned a valve. Cant say I've ever seen one do that before.
Glad to hear they hopefully have it figured out though.

Any specific question you would ask? I'm planning to dig as deep as I can with them. Lord only knows how long I'll be without my bronco....

 

[BlueWaffle]

Won't a bad vvt solenoid mimic/cause a low compression issue?

 

[Ducati1098]

Any specific question you would ask? I'm planning to dig as deep as I can with them. Lord only knows how long I'll be without my bronco....

I'd ask them what they think caused a burnt valve. That doesn't typically just happen out of nowhere unless something else caused it.
I'd also see if they can send you some pictures of it, because I'm assuming it's torn down already.

 

[Ducati1098]

Won't a bad vvt solenoid mimic/cause a low compression issue?

That wouldn't explain a failed compression test.

 

[abz]

tear-down of a volvo 4-cyl that has a burnt valve due to stuck oil control ring

 

[Roach011]

tear-down of a volvo 4-cyl that has a burnt valve due to stuck oil control ring

help me understand the relevance here

 

[abz]

help me understand the relevance here

both the volvo engine and yours have a burned valve

may or may not from the same reason (oil ring on piston not working properly in the volvo case), but that's something to check if the dealer does remove the piston in yours

 

[Roach011]

That wouldn't explain a failed compression test.

Got an update from the dealer - burned valve from running lean. no piston or cylinder damage, calling for a head replacement. All covered under warranty, looking into parts availability now. I'm supposed to talk to the actual tech at some point today. Anything specific I should ask? I'm mostly concerned about down stream effects of running lean for who knows how long.

 

[Brian_B]

Anything specific I should ask? I'm mostly concerned about down stream effects of running lean for who knows how long.

If there was no issues inside the cylinders, the other thing to worry about would be the catalytic. Lean burn means higher than normal temps, and possibly turbo bearings (although those are usually pretty obvious).

I'd be questioning why it ran so lean - unless you already know the answer to that one and just don't want to say it out loud.

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