[abkonsta]

New to me, 2009 BMW 335i, with 59k miles on it.
Has a strong metallic top end "tick", like in all the videos I looked at. Tick can be heard with the plastic engine cover on and the hood closed/

Today I took the valve cover off to take some pictures. Here is what I found:

This pair is the two exhaust valves, #4.
On the left is what I presume a normal rocker.
The one on the right appears to be crooked and also very sooty.
Is this / can this be the source of my tick?
What are my next steps?





Also, there was a lot of sludge around ##4, 5, 6:

[Smgs1992]

Well you need a walnut blast but a tick is normal for a direct injection engine assuming that is the ticking noise you're referring to.

[abkonsta]

Originally Posted by Smgs1992

Well you need a walnut blast but a tick is normal for a direct injection engine assuming that is the ticking noise you're referring to.

Maybe "tick" is too mild a word. Its the kind I can hear in the house when the car is idling outside, or the kind reflecting from the walls of buildings when I drive close to them.

It is also the kind that occasionally triggers the knock sensors like this guy here described:

https://www.e90post.com/forums/showthread.php?t=1520525

[///Motivated]

That rocker is annihilated. Probably need the lash adjuster, a rocker and a camshaft. Does the rocker flop around when you touch it?

[abkonsta]

Originally Posted by ///Motivated

That rocker is annihilated. Probably need the lash adjuster, a rocker and a camshaft. Does the rocker flop around when you touch it?

No, not really, but that may just be because of the position of the cam... I am in the process of removing the fan, and then I will turn the motor and watch what it does.

Waiting on the timing tool from Amazon, should be here Wednesday.

[abkonsta]

Got the fan out, rotated the motor maybe 10 degrees, to let the valve stem "top out". Yeah, that rocker is super loose.

[abkonsta]

Here is the rocker that was destroyed:



Bad rocker next to the one that was alright:




Only one destroyed rocker.

Replacing the rocker and its lifter, although, honestly, I couldnt see anything wrong with the lifter either

The camshaft lobes didn't seem to have any unusual wear either. I measured the max lobe width with calipers, on both sides, didn't find anything out of the ordinary.

[abkonsta]

New rocker, new lifter just in case.
Since I couldn't see anything wrong with the camshaft, I put the old one back in.
Put everything back together. 100% improvement - no knock, been driving it around for a couple of days, engine knock code has not come back... I think we're in the clear!

So, exactly as in ///Motivated's case, my top end knock (bad rocker) was occasionally setting off the detonation knock sensor.

[///Motivated]

Late reply here. The lifter didn't look bad, but the reason the rocker messed up was because the lifter didn't pump up to remove the lash. When there is lash the cam lobe smashes into the rocker (roller) and eventually beats up the bearing to where the roller won't roll. Then the sliding friction wears down the roller until things get all messed up. The lifter that didn't pump up was the root cause of the rest of the failures.

[stewbets]

Thanks for the explanation!

[VccE92m3]

Originally Posted by ///Motivated

That rocker is annihilated. Probably need the lash adjuster, a rocker and a camshaft. Does the rocker flop around when you touch it?

My motor has had the same strong ticking sound and when i opened it up 2 of the rocker arms would flop around and were missing some of the retention spring would that cause a ticking/knocking sound ?