thompsoj22
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Bump, Back in the lineup!
2012 Yukon XL Denali 6.2L Cam Swap Thread
- Thread starter Geotrash
- Start date
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OP
OP
Love you guys - thanks for checking in. Got home from our 2,000 mile trip on Saturday and the old '07 with 211K on the clock did great hauling our camper. Sunday was unpack and clean, and this afternoon I'll finally get back into the project.
OP
OP
Alright gents, work has begun again. Oil pan is off, oil pump is off, no nicks or cuts noted with the O-ring for the pick up tube. Looks perfect, and I did install it correctly.
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OP
OP
I don’t! Thank you for the offer, but I’m going to have this thing buttoned up tomorrow I think. Out of curiosity though, what do they look like?
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OP
OP
Got the driver’s side cylinder head off and found one bad lifter so far. It was the #5 exhaust. That also matches well with the cam lobe that was the most damaged. That said, to my eye, none of the other lifters look like the rollers are damaged at all.
Thoughts? I’m wondering if maybe a bit of grit got in there and stuck the roller. Either way though, the cam was definitely trashed. On most of the lobes in fact.
One more thing… When I installed the pick up tube into the new milling oil pump, the O-ring was a much more snug fit than the one I installed in the factory pump last time around. I’m wondering if even though I got the right red O-ring last time, if it was undersized.
Thoughts? I’m wondering if maybe a bit of grit got in there and stuck the roller. Either way though, the cam was definitely trashed. On most of the lobes in fact.
One more thing… When I installed the pick up tube into the new milling oil pump, the O-ring was a much more snug fit than the one I installed in the factory pump last time around. I’m wondering if even though I got the right red O-ring last time, if it was undersized.
iamdub
Full Access Member
Got the driver’s side cylinder head off and found one bad lifter so far. It was the #5 exhaust. That also matches well with the cam lobe that was the most damaged. That said, to my eye, none of the other lifters look like the rollers are damaged at all.
Thoughts? I’m wondering if maybe a bit of grit got in there and stuck the roller. Either way though, the cam was definitely trashed. On most of the lobes in fact.
One more thing… When I installed the pick up tube into the new milling oil pump, the O-ring was a much more snug fit than the one I installed in the factory pump last time around. I’m wondering if even though I got the right red O-ring last time, if it was undersized.
Is that edge of the roller ground off, like it rubbed against the cam lobe or is it broken off, like the metal fractured?
OP
OP
It looks to my eye like a chunk came out of the metal, and then the roller got stuck and burnished the rest of it. The roller moves freely, so I suppose it could’ve been a chunk of debris in the roller bearing at some point, but hard to say.
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iamdub
Full Access Member
Or a fracture in the roller that missed QC or was otherwise invisible. The roller fractures and the metal goes through the oil system, scarring the cam lobes, journals and bearings. The chunk of debris that stopped the roller from moving could've been a piece of the roller itself.
iamdub
Full Access Member
This is what I'm thinking. Maybe a flaw in the hardening process?
randeez
Full Access Member
OP
OP
Oil pressure was definitely lower than before the swap so something was off, but I agree, the engine was likely getting enough oil. No issues anywhere else but the cam lobes. Even the cam bearings were fine, and the cam was dripping with oil when I pulled it out.
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OP
OP
New cam is in and the heads are back on. Timing marks are lined up and she’s getting ready to rock - hopefully later this week!
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OP
OP
Also, the Fel-Pro Perma torque MLS head gaskets looked like new when I pulled them out, but I used new ones anyway. Any opinions about reusing them?
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Agree. I’d find better places to try and save money. There is some money I can’t afford to save and this would be some of it.
thompsoj22
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Got the driver’s side cylinder head off and found one bad lifter so far. It was the #5 exhaust. That also matches well with the cam lobe that was the most damaged. That said, to my eye, none of the other lifters look like the rollers are damaged at all.
Thoughts? I’m wondering if maybe a bit of grit got in there and stuck the roller. Either way though, the cam was definitely trashed. On most of the lobes in fact.
One more thing… When I installed the pick up tube into the new milling oil pump, the O-ring was a much more snug fit than the one I installed in the factory pump last time around. I’m wondering if even though I got the right red O-ring last time, if it was undersized.
Yup, Ill second the opinion of soft/defective cam, Possibly the hardened rollers started destroying the soft cam material from the first startup. Shame how our perception of "quality" is based upon a small companys intent of putting out a good product but you might have an employee with a F'it attitude on a monday/friday and somthing like this happens. This project educated me, And when i do need to reman our engine i will only use OEM components. No hacking intended, It is simply getting so hard to find quality that is real as opposed to simply a verbiage marketing strategy.
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