M119 with engine knock

[edwin.dario]

Hi everyone,

I recently picked-up a W124 body car which was converted to a 500E.

One of the previous owners spent hundreds of hours putting this project together.

I purchased the car with no information on the engine except for the video below. My seller was not the one that built the car and he only went so far as to try to start the car, as seen on the video.

I am therefore looking at doing some investigative work before deciding the next steps.

I started by removing the filter, that’s when I saw pieces of plastic. I removed the biggest from the filter.

There are some metallic shavings in the filter but very little.

I then read up on the chain guides failing and I thought to pull the valve cover to see whether the chain guides had failed.

The visible chain guides looked ok and complete (from my limited view, I could only see a top chain guide and another on the side from each side of the engine.

I then checked timing… timing was spot on without any deviation whatsoever.

Which brings me to the purpose of my post…. What would you recommend that I do next in order to troubleshoot the noise? Should I just button everything back up and then try to start the engine

 

[edwin.dario]

Btw, the cam oiler tubes are metallic (not sure that it matters).

 

[Alphasud40]

I would remove the oil pan and see what you find. Easy job might give more clues to what’s going on.

 

[nocfn]

yes whatever broke to find the filter must be too big to get thru and is laying in the pan. I had lost a guide on the 126 when I first bought the car and luckily the tensioner took up the slack. A big part was in the pan, and a slightly smaller part wedged between the metal surfaces and the chain. shaving off plastic. Surprisingly I did not break timing.

 

[gsxr]

Can you isolate exactly where the noise is coming from? It doesn't sound like bottom end (which is good). If all chain rails are intact and cam timing is correct on all 4 cams, something else is up. In the video it almost sounds more like the cam adjusters rattling.

Is oil pressure normal? I assume you have tried running the engine with the belt removed to confirm it's not a belt-driven accessory?

After all that... time to drop the lower oil pan to check down below.

 

[Eno]

Lower plastic chain rail guides needs replacing and rubber part on the bottom of the oil pump near the bottom of the oil pan.

 

[bicylindrico]

May be a possibility

 

[LameyerBobonov]

Since you’ve found plastic pieces and metallic shavings in the oil filter, it’s wise to do an oil change with a new filter. This will help remove any contaminants that may cause further issues. Before buttoning everything back up, check for any debris or leftover plastic in the oil passages, valve cover, and elsewhere. Ensure the oil pickup and screen are clean to avoid clogging when you start the engine.