#6 exhaust eccentric wear

[Cabriolet]

So my dad and I do tons of valve adjustment for local e30s. Something we've noticed and replaced the most of, by far, is the eccentric on the exhaust valve of the 6th cylinder. does anyone know why this one would wear so much?

75,000 mile engine:


*we did not replace this one this time but it will need to be replace at 100k miles.*

[TobyB]

Interesting.

Wonder if it's a geometry problem...

t

[whodwho]

Not sure which end the oil supply is for the oil bar but maybe less oiling at that end

I would look into replacing those headbolts before one lets go ;)

[jlevie]

I'd guess on low oil pressure or a clogged spray bar.

[Cabriolet]

I'd guess on low oil pressure or a clogged spray bar.

But why is this happening on nearly every m20 we work on? ... like 15-17/20 of the cars we've done.

Not sure which end the oil supply is for the oil bar but maybe less oiling at that end

I would look into replacing those headbolts before one lets go ;)

not my car so, the owner will have to do that.

i wonder if there is an m20 starvation issue. they arent usually dry.

[jlevie]

But why is this happening on nearly every m20 we work on? ... like 15-17/20 of the cars we've done.

Quite possibly because the car's aren't getting the maintenance that is appropriate to how the cars are used (timely oil/filter changes and the correct oil). That kindo of wear can also result from seriously exceeding the valve adjustment interval.

i wonder if there is an m20 starvation issue. they arent usually dry.

M20 engines won't experience oil stavation in coreners on the street, but will if used in the stock configuration on track.

[M3 Ryan]

Looks like a fairly normal wear pattern. There is metal on metal movement there every time the rocker moves. Some wear is to be expected, hence why we do valve adjustments...