Bad lobe
Thread Starter
Cruising
Joined: Feb 2010
Posts: 12
Likes: 0
From: Redding CA
Bad lobe
My 10 yo was making a ticking sound. I knew it was going to be an expensive repair. My retired mechanic neighbor thought so sure it sounded like a bad valve lifter. So I wasn't prepared for a broken lobe. "Sorry about that. That's awful.", blah blah.
Has anyone seen anything like this? (Local GM specialist repair shop said it's most likely a manufacturer defect.) Thanks so much for any help!
jjasper
Has anyone seen anything like this? (Local GM specialist repair shop said it's most likely a manufacturer defect.) Thanks so much for any help!
jjasper
Drifting
Joined: May 2007
Posts: 1,547
Likes: 210
From: Huntersville, NC
it looks fatigue crack and it looks like the origin is an inclusion in the cam. I would doubt you would have a recourse with GM over that. There are always small inclusions in steel, and just your bad luck. It is unusual to see one participate in fatigue, but who knows what the root cause is. The fracture face has what are called "beach marks" which are sometimes attributed to the crack propagating. If you can see them, they seem to get smaller in diameter as they get to that inclusion, so that's a rough guess of the origin. Unusual to see one start in the material, and not at a surface or a notch, but maybe the inclusion served as a notch.
you would have to have a lot of proof that there was a manufacturing "defect".
you would have to have a lot of proof that there was a manufacturing "defect".
Safety Car
Joined: Apr 2007
Posts: 3,582
Likes: 137
From: SoCal CA
No biggie? Till you find the all that metal went through all the bearings. Then he'll be wondering why he has 15psi of oil pressure after his "hot cam" upgrade.
OP, thoroughly have your motor checked out and every bit of that metal drained out. Cut your filter open and see how much metal it trapped.
OP, thoroughly have your motor checked out and every bit of that metal drained out. Cut your filter open and see how much metal it trapped.
Last edited by C5Natie; Sep 21, 2014 at 08:00 PM.
Race Director
Joined: Mar 2008
Posts: 12,413
Likes: 502
From: Rio Rancho NM
No biggie? Till you find the all that metal went through all the bearings. Then he'll be wondering why he has 15psi of oil pressure after his "hot cam" upgrade.
OP, thoroughly have your motor checked out and every bit of that metal drained out. Cut your filter open and see how much metal it trapped.
OP, thoroughly have your motor checked out and every bit of that metal drained out. Cut your filter open and see how much metal it trapped.
fwiw: 15psi at idle depending on temp is within spec per gm/manual
Safety Car
Joined: Apr 2007
Posts: 3,582
Likes: 137
From: SoCal CA
Yeah, i wouldnt go off GM's oil pressure specs. Lol. I lost a motor due to a chewed up cam lobe. The last two days of its life I was seeing 15psi till it went to 7psi. Thats why I said that.
OP, good luck. Hope damage is minimal and its an easy fix.
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