1987 W124 300D rough idle and smokes
 

I had the fuel injectors rebuilt, new timing chain,new glow plugs, all filters and fluids changed. Last month I put new tires on the car with updated mercedes wheels. The a'c has never worked but the heat works great. Recently the car started to run a bit rough at idle and would smoke. I had the problem diagnosed as a bad fuel pump. I promptly had the fuel pump rebuilt and properly calibrated ( Over $1000 for this job) and the car still acts the same way. The car drives great on the highway. It's just at idle the car smokes......Valve seals, maybe???????

The following additional questions please:

1) Describe the color of the smoke. I'm presuming white smoke, correct?

2) Will it smoke at idle without any rpm's applied? Will increasing rpm's cause the smoke to worsen or get better?

3) Smell the smoke. Does it smell like fuel,or like oil, or like antifreeze?

4) What's the oil consumption rate?

5) What's the coolant consumption rate?

6) What's the fuel economy? Can you compare the current fuel economy, accurately, to the fuel economy prior to the "event".

Brian, I've been having the same problem and here are the answers.
1) smoke is black sometimes after warm it has a blue tint
2)less smoke at high rpm's but only after the car gets to 85c
3)smoke smells like diesel and very strong
4)one quart of oil (rotella 15w-50) every 3500 miles
5)coolant consumption is perfect. I replaced the radiator and aux water pump 4000miles ago and since it has not come off the mark in the tank. Yes i do have the #14 head coolant is perfect color and tests to -30.
6) I had a shop adjust the injection pump timing and the alda. As I found out the alda and the turbo overload switch were not properly hooked up. I have had a furious decrease in fuel economy since. I am also scheduled to have the Trap recall done this feb. I have been through the EGR post and have done the "BB" fix yet I have not taken the egr off to make sure it is closed all the way.

To better describe the smoking. I have been around every gas 6cyl in existance and when the car is warmed up it sounds like it is misfiring at 700rpm when I bring it up to 1500 it smooths out nicley. I am understanding that the trap may be part of the problem and The EGR was not helping. I have been having fun with the miteyvac and have noticed that EVERTHING runs lower pressure than what the service manual calls for.

I forgot to add that the car runs very slow off the line especially before it gets to 85c. As i'm told it is bad practice to get into the turbo untill it is fully warmed up and I stick to that thought. I also just did a diesel purge and have new fuel filters as of 2 weeks ago.

"I am also scheduled to have the Trap recall done this feb."
Nasty Trap! I had an '87 300D turbo that ran so BAD after rebuilding the engine I almost gave it to charity. Turned out the trap was plugged.
There seems to be no end to problems associated with the trap.
The turbo can also give similar sluggish and fuel rich exhaust symptoms, and the turbo wastegate can get jammed up with carbon and thereby allowing boost to go out the opening and that will make a 603 run very poorly.
You probably have an exhaust related problem, I'd bet either the turbo or the trap or both are involved.
Also don't worry about "getting into the turbo until warmed" These engines like to be driven hard, maybe the oil needs to warm up if your real cold (as it is most winters in WY, right?)
this is also referrd to as an Italian tune up. The worst diesels are those driven by a conservative driver who never lets it rev up good!

don't get me wrong, I'm not afraid of the good ol' redline I just try not to do it till it is warm. I am curious if it is possible to get a new head in the recall as the dealer told me there are three phases to the recall depending on the severity of things;) you may be able to see my motivation (#14 head)

The fact that it does not use oil or coolant is a significant benefit and rules out a bunch of things.

Clearly it is using more fuel than needed and putting out less power than acceptable and shows a rough idle. These first two symptoms are usually mutually exclusive. My thinking is that one, or more than one of the injectors is dripping or putting out a horrible pattern and the fuel is not burning anywhere near proper.

Pull all six injectors and have them tested for pop pressure and spray pattern. If you can't find someone local to do it at a good price, one of our members will do it for $3. per injector. He did mine on the 617 and found one that was NG. He couldn't fix it and I had to get another one. Now, this bad injector didn't cause too much havoc with the 617, but, I'd bet the 603 would be far less tolerant.

Having the trap on there is another variable that is unknown. Get that taken care of ASAP. There might be backpressure in the exhaust causing an issue.

Make SURE that the turbo is checked for bearing clearance and/or damage to the impeller blades. The dealer replaced the trap on the '87 of mine but did not do the turbo. The trap damaged the turbo to the point where it was not rotating. The oil consumption was astronomical.

Thank you

white smoke
 

can someone help me with mine? 1987 300td no recall to exhaust done yet.
i got white smoke only during start up,i also do have some high pressure in the coolant bottle even when cold,the level goes down a bit not much,acceleration is pretty good .

Don't forget engine mounts... shot mounts can cause a very rough idle. They are simple to replace.

New 1987 300D/TD owners should read this, too:
http://www.w124performance.com/docs/mb/articles/124.1x3_buying_tips.txt

:cool:

off with the head:eek:

Sounds like a gasket or head issue.