[29Hersey]

What causes the right hand camshaft to lose a cam lobe?
After pulling it apart the oil feed tubes were not obstructed.
Possibly not the correct oil?
I only drive in summer I was running Castrol GTX 20w50
Too thick? No zinc? Weak hardening process?
You guys are the pros thanks in advance
Only 128,500 MI on car
would like to drive it a while longer
I would like some advice on oil and change intervals.

 

[29Hersey]

Still no takers? I was hoping someone would have an opinion about this. I almost have it back together

 

[Dikdaan]

How was your oil pressure before you discovered the damage? Could be many things. Failed hydraulic compensator will bugger up your clearance then the rocker arm will chew up the lobe chop-chop.

 

[29Hersey]

I never noticed the oil pressure down or fluctuating, I had a lifter tick that would come and go, and then it was there all the time. I pulled valve covers off and found rear cam lobe right side gone.
I haven't checked the hydraulic rocker arm ball stud yet

 

[ianrandom]

Wasn't the restrictive and unbalanced US style exhaust set up thought to affect the right bank like this? Or am I mis-remembering.

 

[Dikdaan]

I never noticed the oil pressure down or fluctuating, I had a lifter tick that would come and go, and then it was there all the time. I pulled valve covers off and found rear cam lobe right side gone.
I haven't checked the hydraulic rocker arm ball stud yet

Yup classic sign of lifter having gone tits up. You will need to pull all the lifters and inspect. Use this opportunity to clean all sludge out of the oil galleries.