I will look in to it thanks. Would the coked turbo cause hunting idle? I know if the turbo seal is bad it will allow oil burning.. I hope this is my issue. Funny because on highway she runs up to redline and will roll 100 mph no problem.

Step 1.Crack injectors and see which cylinders are NOT contributing. Quick tip, problem cylinder will clear up idle exhaust smoke.
Step 2.Do a compression test
If compression is fine you have a fuel problem to a particular cylinder. Injectors, maybe delivery valves

If compression is weak, well there's your problem with idle

You're going down the wrong path imo.

You mean inj. lines right? :cool:

Unlikely that a coked turbo would cause an idle hunt. Unplug the EDS solenoid and see if the hunt stops. If it does, it's probably the computer surging the idle (mine does this sometimes and it's really annoying, I haven't sorted it out 100% yet either). If the hunting continues, you either have a problem in the governor or some sort of fuelling issue. A weak cylinder, bad injector, or IP delivery valve problem will manifest itself as a "skip" or a "miss" but not an idle hunt.



My crappy turbo still had enough punch to get my car up to 113 at a car gathering a few weeks ago, it just looked like the DDT fogger running a crop-dusting run (it was bad!).

Yes

It has to be a mechanical problem, bad electronics don't cause an engine to smoke.

OK ..

Has anyone done an upgraded head gasket in a .971? My cylinder head is an #18. If so where do you purchase it? What is the correct inj.timing for a .971 and would the ip cause over fueling internally? My 971 starts like a champ, but lopes after glow plugs cycle and smokes like a locomotive after until warm. The body is beautiful, and I may 606 transplant her because the 971 may be hurt. It runs on the highway like normal but smokes in different instances. :( Any Merc, Mechanic live in CT who may be able to check it out for me? :)

Uncle Benzz, start simple / cheap (injectors) and then work up to expensive / complicated (head gasket). Don't over-think this. Don't fix what is not broken.

The oil usage is a problem, your engine is a rod-bender, you may want to start with a compression check and / or a leak-down test to establish the health of your engine. My 1987 OM603 with ~390k miles uses about a qt per 1200 miles, I had an OM617 that used a qt every 800 miles with about 360k miles, these engines do wear out. Leaks?

Injectors for your engine last about 100k miles, and then they are probably due for replacement. If you have no records and more than 100k miles on the odometer, start here (injectors). If you can't afford down-time, get a set with new nozzles (don't forget the heat shields for each injector - one-time use item) so you can swap them out in one day. I would not do anything else until you've got this step completed. Use the search tool - many many threads and advice on injectors. Quick start: your engine uses what is called inclined (or oblique) injection, so the injector bodies are different from earlier OM603 engines. Greazzer (member on this list) offers injector rebuild / balancing at a fantastic price, you may have a local Bosch diesel shop that does this or maybe a good MB independent mechanic that does that too. Testing and balancing of the injectors is required for a smooth engine and another 100k miles.

After injectors (the most likely cause of your smoke), your loping idle could be engine control (electronics) or delivery valve seals (which may also contribute to your occasional miss, if the injector service doesn't fix that).

Don't worry about turbo or EGR, given that you can reach 100 mph neither of those are causing an issue that needs to be immediately addressed.

Thanks for the In depth Reply. The body/Interior is really nice on this car. I would like to 606 Super turbo it If in fact the 3.5 is not good. I did have a #2 Prechamber leak and changed it out with a new Injector. Now its time to look at IP and the ETR. Does anyone have a pic of ETR? Also the IP and injectors are dry upon inspection. Would the delivery valves cause internal issues? I did a diesel purge 2xs the solvent/diesel was still dirty black on 2nd time. How many times will it need to be done till its clear:confused:

Problem Found
 

You said : "I did a diesel purge 2xs the solvent/diesel was still dirty black on 2nd time. How many times will it need to be done till its clear"

Until it's done .

I've had a few WS123's that required a full gallon of Diesel Purge before the returning fuel ran clear.....

When you discover a problem, any problem you must fix it before moving on to the next thing .

Has anyone swapped the 603 for 606 on the W140?
 

Pics for Attention ....:eek:

What exactly is the black in the fuel? Carbon/black death? I changed the fuel filters and will have to do it more.

The black stuff is algae/bacteria in the tank. From sitting or moisture got into the tank. Breeds microbes clogs filters and kills power.

I see, so drain tank,clean tank screen. New filters. I gather this can wreck the IP? Car fires and goes down the road well just smokes and crappy low rpm. Smooths out when raised rpm..