e-class knocking

Hi Can anyone help? 1998 e-class 240. Intermittent knocking sound from around front nearside (RHD) at idle. Comes and goes. Can also be heard if engine revved to just above idle but goes then.

Any ideas?

Thanks

Peter

It's the engine?

Marty

Yes, there are jumper tubes on the heads that feed the lifters.......they blow out a plug and let oil squirt onto the head inside the valve cover....find which one/s are bad and buy new from the dealer.. Is your oil pressure low at low idle?

Hi Oil pressure is fine at idle.

I'll see if I can see anything amis with the plug you mention.