camshaft pitting

[slammin240tic]

I recently bought a 1994 volvo 940 turbo. & while changing the oil I noticed under the oil cap It's exceptionally clean, but their's pitting & scaring on the cam lobe's. & It makes a lot of noise on startup. what could have caused this? And is the bottom end possibly damaged from it?

 

[Volvo_ST1]

Is that a relative low mileage vehicle?

 

[slammin240tic]

It has 209xxx miles..

 

[Volvo_ST1]

There goes my theory. I thought that an older car that hadn't been driven much may be more prone to abnormal cam wear. The lobes could be just worn out (too rounded).

Is the pitting mostly on the nose of the lobe? Are all lobes affected? Stuck valves might cause metal fatigue and pitting.

Corrosion is possible.

Maybe someone did a shoddy valve stem seal job and didn't install the old lifters in the same position.

A photo would be helpful.

 

[mechtech2]

Over 200k on an old car?
Are you kidding?

 

[slammin240tic]

Yes the pitting is on the nose or high point on the cam. their flat tappet's could not enough zinc be a cause?

 

[QuadDriver]

not enuf oil to the head(s). It may be age related

that is the #1 cause.

Unless this engine was rebuilt improperly, Im not gonna consider spring bind or bent valve stems

cheapest fix: new cam and followers. or regrind the cam to a smaller base circle and relash the followers (if possible)

Hertzian loading? Is this worse that Avisian loading?