This forum has to be the best source for information on the 113 cars. I have had mine since last October and find the info hear addicting. It is my 1st 113. To make a long story short, I probably would not have bought this particular car knowing what I know now. It was totally misrepresented by the seller in many respects. After driving it home 800 miles with no problems and adding a quart of oil along the way, I took it to my local independant Mercedes mechanic for an inspection. He seemed to be very knowledgable about these particular models and actually had 2 others in his shop for service while I was there. He went through my car and came back with a list of recommended services. Included was a tune-up, trans service, and replace all belts and hoses. I asked him to do a compression check to get an indication of how healthy the engine was which he agreed was a good idea. He came back to me with the following readings:
Cylinder 1 - 150
Cylinder 2 - 130
Cylinder 3 - 130
Cylinder 4 - 140
Cylinder 5 - 95 - (goes over 200 with oil in cylinder and valve clearance)
Cylinder 6 - 150
He says you will need to rebuild the engine and he can do it between $8-9000.00
This news is of course very depressing to me so I start exploring my options. Even thought of throwing in a can of "Engine Restore". 95 in cylinder 5. Um, not good right? One option was to find another motor perhaps even from a 280se. So I find a guy locally who has a 280se for sale which he says runs well. Now keep in mind my engine also seems to run well. I do not see any smoke when it starts or is running. I decide that before I will buy another engine, I will do a compression check on this possible replacement motor.
I go to the parts store and purchase a shiny new compression tester with the 14mm fitting. Since I have not used one of these in a very long time, I decide to try it out on my own 280SL 1st. I start the engine (after battery charge). It starts right up after sitting since November to let it warm up. I read here that the compression test should be done on a warm engine. Again no smoke. After about a 10 minute warmup, I take out all the plugs, disconnect the coil wire (forgot to remove the fuel pump fuse) and start my test. Here is what I came up with:
Cylinder 1 - 180
Cylinder 2 - 170
Cylinder 3 - 170
Cylinder 4 - 180
Cylinder 5 - 135
Cylinder 6 - 184
I call the mechanic who thinks he did his test cold. He also asks if the car sat for a long while. I think it did. He says when a car sits, one cylinder will have its valve open whick allows humidity to enter the combustion chamber and may have caused the rings to stick. The compression differences are relatively consistant across all cylinders but now I am thinking that 135 is allot better than 95 and I may just stay with what I have.
Do you think it would be worth while to put some diesel fuel (I believe it is fuel and not oil correct?) in cylinder 5 an let it soak for a while with the hope of freeing up a potentially stuck ring?
