Gasoline-Engine Camshaft Wear: The Culprit is Blow

[xtell]

Garak,

Both of those engines showed sever camshaft lobe wear on the lobes towards the back of the engine. The front lobes checked out fine. There was no sign of sludge build up and the oil and filters were changed on a regular basis. The oil pumps were also working correctly. Never could figure out why the wear was so bad in the same area on both engines. I replaced the camshafts and timing gear / timing chains on both engines along with new lifters (all AcDelco replacement items). After that, I got 100,000+ miles out of both vehicles with no further issues.

Do you have any incite as to why the wear would have been localized to the rear lobes on both engines? Both vehicles were purchased new and no internal work was ever done to the engines prior to tear down to replace the camshafts.

 

[Garak]

That's a very good question. In my experience with the taxis, the wear wasn't terribly localised, with a fair bit of flattening on a few lobes, but the back possibly good have been worse in some cases. It was a long time ago. And my experience, too, was, upon replacement, no further issues arose. Taxis would often have under 100,000 miles and zero power and the usual symptoms. Open things up, nice flat camshaft, replace it, and 500,000 more miles without a repeat.

 

[Silk]

The Holden 308 used to wear the lifter right through and they would collapse.