jchau123

Took my car into the shop as soon as i heard ticking for a valve adjustment. These are the pics they sent me. Any thoughts?

dagle

those are scarred cams for sure and will need replacing but first you should probably drain your oil and inspect the filter for metal shavings. cam scarring usually occurs from oil starvation and usually scars after the crankshaft in the bottom end suffers damage first. i've taken apart 10+ spun bearing long blocks over the years and have yet to come across one with cam scarring, i'm sure it's possible to scar the cams without rod bearing failure but i've seen the opposite case more often than not.

Billman250

Cam scarring is not from oil starvation. It is from a retainer contacting the roller.

You have broken retainers 100%. Only the last picture shows it.

Slowcrash_101

So the retainer stops the roller from rolling, causing the cam to drag on the roller?

Billman250

The retainer raises up far enough to contact the roller. The roller scrubs powdered metal from the retainer, and presses it into the camshaft.

dagle

there you have it, that works too (though i've never seen it)

Car Analogy

Good thing this is being caught now. Replacing retainers is not especially difficult.

Risk of not having retainers replaced is retainer fails completely, valve drips into cylinder, engine completely destroyed.

The fix is update to ap2 retainers, which don't have this issue. Direct fit to ap1.

Issue caused by a mechanical over rev (aka money shift, accidental downshift when attempting to upshift near redline). The rev limiter doesn't help here, as engine is forced to overrev by cars momentum. Wheels turn diff which turns trans which turns crank which turns cam, which breaks ap1 retainers.

Then sometime down the road, without warning valve drops and engine toast.

So definitely want to have this done asap.

Car Analogy

Billman, does he need to replace the cam? It sounds like you're saying its not scoring of the cam, but rather deposits on the cam that are causing the marks. Did I understand that correctly?

So can he just polish the marks off? Does he even need to?

Since the deposits are from metal from the rollers, does he need to replace the followers?

Is this a remove camshaft scenario, or just replace retainers and done scenario?

Billman250

Powdered deposits are from the retainer. The hardened powder is pressed into the softer camshaft. It leaves the etching/spotted line right down the center.

Will need retainers, cotters, and possibly a cam. Needs to be polished to see if the cam is useable. Followers are fine.

Car Analogy

Good to know!

Is it possible or worth it to try and polish cam in place? Could be a diy for some without the knowledge and confidence to pull cam, and still save a lot of $.

Pay a shop to replace retainers, which is a prerty normal and understood service, and diy cam polish, which would be expensive to pay a shop to do, and less of a known service procedure.