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Discussion Starter #1
Hello 123 Enthusiasts,

I just found out today, the cause of my engine running rough. I did a compression test and Got some pretty appalling results. Car is a 77 230 W123 carburetted. M115.954 engine.

DRY test: #1 60 #2 55 #3 30 #4 58
WET TEST: 185 180 175 180

Anyone who knows half a thing about engines knows that PISTON RINGS are in order.

Now I have decided to rebuild the engine as I need to do one for my class and what better first than an MB engine eh:)
That said, I am not looking to build a rocket out of it, just a reliable daily driver. This car has about 175k miles but was used around town mostly from new. I plan to do rings, rod bearings and head-gasket. I don't plan to delve into the head, unless to change valve stem seals maybe?. The valves have already been adjusted prior to this discovery and the car has had tune up and fluids changed matter of fact i put it for sale on the classifieds but I WILL NOT sell a car with such poor compression. I care about my integrity too much to do that.

What I need from you guys is input on things i should check, and watch out for, sources with good prices for engine gaskets and such. This will be an economy rebuild, i am not looking to dump a ton of cash into it. Thanks in advance for your help.
 

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Considering the Mileage on the Engine you would think that it is worn out too soon.

This makes me think that the City driving has caused stuck Piston Rings.

You might try removing the Spark Plugs and pouring in some Marvel Mystery Oil and letting it soak for a week, rotate the engine 180 degrees and repeat the process.

After that with the Spark Plugs still out crank the Engine to blow out any excess Oil before getting your Engine ready to start.

The above soaking worked for me on a Volvo Diesel that had sat not running for 1 year and the Thermostat was opening too soon. I had hazy gray smoke all of the time.

After doing the soak and driving for 3 days the hazy smoke went away.

I have also read that after using Synthetic Oil and after driving 200-300 miles will also free up stuck Rings.

The MM Oil is cheap and it seems to work if carbon is causing the stuck rings.
 

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Discussion Starter #3
As at today by 4pm the powerplant is out of the car. Next week will be interesting and we will see what kind of wear is in there, i will try to post pics
 

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what did you have to remove to get the head out? I have been working on mine for two days and it seems like there are endless obstacles to overcome; a bolt here, a bolt there. did you have to remove the power steering unit or the ac unit?
 
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