86 W124 300D smoking black

[MBDFahrer]

Hey everyone. Recently my dad met a guy at a Pick-n-Pull yard who they became buddies. He has a shop and has allowed me to work there. As I was there to check it out, he has a 86 300D thats been in storage for 2 years.

He acquired the car for nearly nothing with only 121k miles . The problem with it (which is why its been in storage) is that when its running, it has thick black smoke. At first i thought it was a blown head (it does have the 14 head), but that usually results in white smoke.

I think next week we'll change the filters, drain the tank and put in a tank of fresh diesel, started it up and see whats going on. I'll take pictures and post them here for all to learn.

I think someone's 2.5 turbo was doing the same thing and was asking whether to buy it or not.

Thanks for reading, have a nice day.

[psfred]

Jason:

Has to be an 85 or an 86, no 300D in 1986, only the 300SDL.

Doesn't matter all that much though, if you get huge clouds of black smoke under load, buy it cheap, most likely the EGR is sticking open!

This will greatly reduce power, cause a funny muted rattley knock, and HUGE clouds of black smoke (no air, in spite of the boost, so LOTS of unburned fuel). Car behind will vanish if you kick it down, right?

Plate off the EGR (or replace it) and the smoke will magically vanish.

If it's not that, the timing is way off, and that could be a bad repair (the injection timer can slip on the 603 if you don't use the holding tool) or a bad IP. Bad IP is expensive.....

Peter

[MBDFahrer]

Thanks for writing Pete. I'm not intending to buy this car, just merely "trading knowledge", I'll be using his shop to repaint my car and other mechanical or body work, in return I'll be giving him tips/tricks on Mercedes diesel. He would sign up to the forums, but doesn't have a computer .

Other cars of his fleet is a 78 300SD and 2 W123 300Ds of unknown year doing body work.

If it is a diesel, usually, it is injector timing, bad fuel, or injectors are badly worn You need to replace injectors every 100,000 miles for good performance. Also check tming change and egr valve.

[Mr. FancyPants]

Originally Posted by yago

If it is a diesel, usually, it is injector timing, bad fuel, or injectors are badly worn You need to replace injectors every 100,000 miles for good performance. Also check tming change and egr valve.

Injectors don't need to be replaced every 100K! You might volunteer to rebuild them at 200K if one or more are nailing. Or at the very least, take them apart and clean them and have them balanced. Many here I've read have as much as 300K or more on original injectors.

Steve.........

[Hatterasguy]

Mercedes injectors don't need to be replaced every 100k miles, they should be checked at 200k maybe.

[gsxr]

Check the air filter first. If the car is a 1986, it's gray market, and probably non-turbo. Checking the EGR is a good idea. It's also possible the car blew the head gasket in front of the #1 cylinder into the timing chain cavity, and it sucking oil in - but you would smell burning oil out the tailpipe. Another possibility (on a turbo engine) is a cracked ALDA capsule, which would result in over-fueling at idle and low boost. Lots of things, really. You'll need him to get the car out of storage, fire it up, and provide more details. Oh, if you can get the VIN, we can tell if it's a USA or Euro model!