Engine knock :( (615 and 617) - Page 3 - PeachParts Mercedes-Benz Forum

barry123400 · #31 07-05-2012, 06:13 PM

Hopefully the rod bearing is still good. My fear was that in trying to establish what the noise was you might increase the damage if the rod bearing was going out.

That may be a piece of bearing material in the pan you found. A close up picture of it posted might help if possible to do and keep it in focus. It of course could be something else. It is never a total waste of time to check out the condition of the number one rod bearing especially on the four cylinder engines in my opinion. Less so on the five cylinder blocks yet still relevant.

Raptelan · #32 07-05-2012, 07:18 PM

Quote:

Originally Posted by DieselPaul

Pulling off a rod cap is the best advice you've gotten so far. Try it.

I'm not sure how to do that, yet. That's the part that can be done with the engine still in the car? I've got a lift but don't yet have a hoist...

Quote:

Also, if you put in a "US" 220D OM615, whats to say you can't put the Euro 200D manifolds on the US long block?

It has 616 manifolds like a 240D, actually:

I may end up opting to put in a 240D, at least temporarily to have a usable car. That would destroy the uniqueness of the car though. W123 200D's are actually not uncommon at all worldwide, but were never sold in the US and very few were imported since most would have opted for a larger engine.

kerry · #33 07-05-2012, 07:53 PM

It can be done in about 10 minutes now that you have the pan off. Get the #1 rod in the most accessible position, remove the nuts holding the cap on and pull the cap off. Keep track of the orientation of the cap and the orientation of the bearing when you remove it so it can be reinstalled in the same manner.

Raptelan · #34 07-05-2012, 08:10 PM

Quote:

Originally Posted by kerry

It can be done in about 10 minutes now that you have the pan off. Get the #1 rod in the most accessible position, remove the nuts holding the cap on and pull the cap off. Keep track of the orientation of the cap and the orientation of the bearing when you remove it so it can be reinstalled in the same manner.

Thanks, I'm sure this is all basic once you have a clue about it - I just don't yet. Would details about this be covered in the factory service manual for the engine (which I have)? Or do you know of good online resources that document the process with pictures?

kerry · #35 07-05-2012, 08:28 PM

Should be in the FSM. Just lay under the oil pan and look up. Identify the connecting rod. The one furthest toward the front of the car is the #1. It connects to the crankshaft with a bearing that is in two halves bolted together. You can see the bolts holding the rod cap half on to the half that is a part of the rod.

benedict · #36 07-05-2012, 08:48 PM

It would be great to keep the original motor in that car especially as it is pretty rare in the US (and here in Australia too, just the occasional personal import by expats)

That engine is obnoxiously loud and great for disturbing annoying neighbours during morning warmups

Putting in a 240 whilst you repair or even freshen up yours as you suggested, sounds like a good option.

If it was mine I wouldn't keep driving it because if something throws out, it could blow a hole in the side of the motor. And bit harder to get parts for a 615 I can imagine.

barry123400 · #37 07-07-2012, 09:51 AM

When and if you do pull the rod cap make sure to follow some suggestions that may be made. Even if it looks decent you will have to plastic gauge it.

This is basically squeezing a piece of plastic between the bearing surface andf the crankshaft surface. This to indicate what clearance is present if the bearing and crankshaft surfaces appear normal.

It is a bit premature to feel the engine has to be changed out. Presently you only have an unidentified noise.