Compression Test Results - PeachParts Mercedes-Benz Forum

#1 04-26-2002, 11:57 AM

From my '72 107 M116 - 170, 160, 160, 160, 135, 150, 160, 150

OK, I'm not a mechanic but I'd like to know a little bit about this before I send it back to the shop, if I have to. #5 looks real low and #6&8 look low. What does the low compression mean to the engine and could this be causing the following: Car starts fine, idles a little ruff while cold. I start down the street which gets the car to 3rd gear (auto). I've got a stop light there and everytime I have to stop the car blows dark/bluish smoke and studders like it's missing until I get it to crusing speed, say 40mph. After it warms up it's fine.

autozen · #2 04-28-2002, 12:10 PM

Steve,

I wouldn't worry so much about the compression readings as long as the car idles and runs well warm.The cyl with 170 may be pushing some oil. Find a good shop to diagnose your problem. There are too many possibilities to do on the internet.Again by the way to even out those comp readings will cost more than the car is worth. Put that money into a new heater box to correct those jammed heater levers you are experiencing.

Good luck,
Peter

#3 04-29-2002, 08:42 AM

Thanks for the insight Peter,

"heater box and jammed heater levers" ? I'm not tracking on this though.

autozen · #4 04-30-2002, 11:37 AM

Steve,
The heater on the earlier 107 cars was turned on and off by a valve mounted on the firewall opening and closing. As soon as you move one of the red heater levers up slightly, the valve opens fully. You control the amount of air passing over the core with those levers. Each lever controls a flap in the heater box. Over time the hinge on the flaps go kaputin and you can't control the heat.The whole dash and heater box have to come out. I've never found a way to repair one.
Good luck,
Peter

daddiojiggy · #5 04-30-2002, 09:01 PM

autozen,why do you say the cyl reading 170 maybe blowing oil?i thought the higher the number the better

autozen · #6 04-30-2002, 10:30 PM

Oil seals rings which is why you do a wet test on low cylinders during a compression test. You squirt oil into a cyl, and if compression comes up dramatically,there is a problem with rings. You can't seal valves with oil.

Peter