i have a 95 240 with 170k miles and theres a noise near one of the two back pistons somewhere inside the valve cover. it sounds kind of like a spark plug firing, but its loud enough to hear over the engine noise...

just wondering if anyone else is experiencing the same, or knows what it is?

 

I'd say exhaust leak...blow cigarette smoke near the exhaust manifold and if you see it shoot away from the engine, you know its leaking...if it's inside the valvecover...ya gotta open it up to see what it is. But if its that loud...id say take off the heat sheild and look at the exhaust manifold.

 

the exhaust manifold sounds like a good idea but i put a screw driver up to the intake side of the valve cover and thats where i think its coming from... but ill check the exhaust too

 

Check the valve lash bro...or.....Have someone check the valve lash bro......

-Joe

 

valve lash?

 

play in valve movement.... could be too lose and slapping...

 

oh ok thanks