Easy Rawlins

My father in law has a 1981 240D with over 400K miles. He has smoke at start up, vibration at start up but it runs relatively smooth at speed.

His mechanic says the number 3 cylinder has low compression. I would like any info/advice on engine replacement or overhaul. This car is my father in law's "baby" and he was going to sell but couldn't bear it. The car is in Jacksonville Florida.

Thanks!

Easy

StevieBenz

I know you probably ruled these things out being the car has 400k on it but are you sure the smoke at start up isn't just a bad glow plug or injector? And does it vibarate when it idles or just at start up? Could be bad motor mounts. If the engine is bad and your father inlaw doesn't mind spending the money, check out [url] There site says they have a rebuilt motor for $2500+shipping and core charge.

Goodluck!

Outre

As the Valves wear in their seats the Valve clearances become tighter. This can make a compression reading inaccurate.

Ideally before a compression reading is taken the Valves clearances should be adjusted and the Car a bunch of miles and then do the Compression test.

The expensive items on the Engine are the Pistons, Valves and the paired set of shafts ($400+) that drive the Fuel Injection Pump Timer and the Oil Pump.

The main thing about rebuilds is you need to tear the Engine down and inspect and measure the components and see what needs replacing before you make a decision.
You might try instilling a 1/4 cup of Marvel Mystery Oil into each of the either through the Glow Plug Holes or the Injector Holes. However, in order for it to work the Car needs to sit for at least a full Week. And, it would be better if you rotated the Engine and repeated it for another Week.
At the end of the soaking time the Engine should be cranked without the Injectors or Glow Plugs installed to blow out any liquid Oil.

Replace either the Injectors or Glow plugs.

Do an Oil Change to get rid of the Marvel M Oil the dripped into the Oil Pan and take the Car for a ride on the Freeway.
The idea is to free up any sticking Piston Rings.

After the above do a compression test again; or if the bad symptoms went away just drive the Car.

I gave the above infor because of the mentione compression issue.
As the other member said check the Glow Plugs.
But, worn out injectors can also cause you to smoke and vibrate until the Engine is worn.

Easy Rawlins

Thanks for the info... A little clarification... even when the car is warm when he comes to a light or is at idle he has the vibration and smoke. It still smokes at speed but not as much.

Easy

StevieBenz

Heres the site http://www.remanufactured.com/Mercedes_Engines.htm
Sorry about that don't know why it wasn't in my original post