Mercedes-Benz Forum banner

1972 250c Engine noise

3955 Views 13 Replies 6 Participants Last post by  agillot
Just purchased a 1972 250c, overall good shape, however engine makes a knocking sound. The previous owner said that a head job was done (doubt it), but could it be possible that the job was done incorrectly? Also, what could be the most probable cause for an engine to knock?

If so, is this particular engine hard to rebuilt?

1 - 6 of 14 Posts
head job

Not sure what they did. Supposedly he spent 3k on the head job, but who knows what they did. If the head was indeed shaved too low, would I need a new one? Could it be possible that a valve is slapping on the top of a piston?

I think the previous owner did play with the distributor and points as well as carb work. But I will try what you mentioned since that is an easy and cost effective method.

Tried the method you suggested, it turns out that cylinder #6 I believe...closest to firewall is the culprit. Does this mean I have to tear down entire engine or just repair that cylinder?? If so, does anyone have a good motor?

FYI, it looks like someone changed the engine to a 280c since the head is stamped 280s on the side.
Interesting about the timing issue. It may be that the PO played with the head and had it installed or timed wrong. I see that a lot of Mickey Mouse was performed on engine (like changing one spark wire cable instead of all of them). And yes, I live in a hot weather climate. The engine is stamped 130.923 serial and the head 1300161201 with the 280s on the side. I am not too familiar with these gas engines, but could an early w114 have a 2.8L engine from factory? And I will try to get a video on You Tube so I can show what the sound it is making.
That would be great. I would like to find out if the engine in the car is the right one.
1 - 6 of 14 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.