Cam lobe wear

[yradave]

Hi folks.

I've had some problms with the hydraulic lifters in my engine. One of them failed and I'm worried it damaged my cam lobe, or that cam lobe wear caused it to fail.

How smooth should the surface of the lobe be? Any reference seems to be along the lines of 'check the camshaft for wear and replace if necessary' type advice, but I'm not sure what level of wear is acceptable.

Is it a case of visible marks that don't catch your fingernail are okay, or is it absolutely no marks and a mirror smooth surface only?

Obviously huge missing chunks would be a big red flag, but I don't really know the difference between a bit worn and completely unusable.

I know it seems a bit of a noob/dumb question, but I realy don't know of any rules of thumb for this kind of thing.

Any help would be great.

Thanks, Dave.

[Rich]

What car is it? What engine? If its common enough it might be worth sourcing one and replacing it for piece of mind. The best thing would be to get some pictures, then we can help asses your cam itself. Normally any marks you can feel are a bad thing, but a bit of discolouration and consistent use wear are ok as long as they are in line with the other lobes.

[yradave]

Ooops should have said, it's a VW Transporter T3 (or T25) with a 2 litre type 4 aircooled engine.

The cam is in the middle of the engine so it's pretty difficult to see, let alone photograph.

I've spotted a gouge on the lobe and marks on the face of a tappet today, so I think my cam is shot and the tappets are due for replacing as well.

It's a shame, as I'll need to strip the engine and split the case to change it.

[Rich]

Ahh, I see. You have to be careful with the be flat 4's anyway as one cam lobe Runs 2 lifters, opposed. (if you didn't already know that)