Anyone have a good cam/crank scope trace I can look at please?
2008 trailblazer 4.2
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Basket case. Questionable "rebuilt" engine installed by who knows and hasn't started since install. Been to three shops already, all with different diagnoses. I suspect its out of time. I scoped cam and crank and none of the rising/falling edges align. Fairly big job to pull valve cover and confirm.Comment
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Yeah but from what I recall you can't see the bottom timing mark on the crank. And you have to remove the oil pan in order to remove the front timing chain cover.
Which basically means engine out on this model...
It's interesting that someone installed a rebuilt motor that won't start and it's been to 3 different shops with 3 different Diagnoses.
What failed on the original engine that required a replacement?
No one from the other 3 shops wanted to work on it?
Owner doesn't want to spend any more money?
As mentioned any other diagnostics like compression test been performed? Any Codes?Comment
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Yeah but from what I recall you can't see the bottom timing mark on the crank. And you have to remove the oil pan in order to remove the front timing chain cover.
Which basically means engine out on this model...
It's interesting that someone installed a rebuilt motor that won't start and it's been to 3 different shops with 3 different Diagnoses.
What failed on the original engine that required a replacement?
No one from the other 3 shops wanted to work on it?
Owner doesn't want to spend any more money?
As mentioned any other diagnostics like compression test been performed? Any Codes?
Don't have any history or explanations.
Plus I don't want to waste anymore of my time if they aren't willing to pay to fix.Comment
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Tell them to hand over some cash before you can do anymore diagComment
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Interesting tidbits of data PID info for future reference.
While cranking Cam and Crank PIDs show RPM, however engine RPM PID shows zero. Also no coil trigger from PCM.
The engine in this vehicle had 7 tooth crank reluctor.
The 2008 model is supposed to have 58.Comment
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Hi,
I found this site not long ago has lots of ckp/cam correlation
scope patterns inc Trailblazer. https://rotkee.com/en/waveform-library?system=51
CheersComment
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