This is for my friend again, he's got one problem after another on this car. The body is a '91 300D Turbo. He has a '93 engine in it that was transplanted over 1 year ago.

This car apparently runs so rough when he first starts it (after a full glow cycle) that it dies about 3 times before it settles down and is finally able to idle properly on its own (once warmed up).

The things I've suspected were the glow plugs - I've checked them for him 3 mnths ago and had to replace one and it was good for a while. Maybe another glow plug died and it's now running rough again. Also, I need to ask him to start keeping track of the oil usage in that car. He says the smoke on startup is blue/deep blue.

What else should I check for him?

__________________
1987 Mercedes 300SDL; SOLD
1985 Mercedes 300D; SOLD
2006 Honda Pilot - wife's ride; 122K;
1995 Toyota Land Cruiser - 3X locked; 182K

Smoke spells: OIL Burning

That,and the Rough Running at Start Up,Rings the "Compression (Rings) Klaxon"
[Worn Rings will cause lack of compression on a cold engine at startup,which
is PARTIALLY compensated for by warming engine]

Did the Donor OM602 ever run on ANY form of Veggie?
["Veggie" WILL Glom up the rings and make them Stick]

OR (Maybe Worse) Turbo Oil Seals.
[See if there's fresh liquid Oil in the Intake "Crossover"]

Bad Valve Train Components allow Leak Down of Oil into the Compression Chamber when the Engine is cool and at rest.

__________________
'84 300SD sold
124.128

We need do a compression check on this thing to see what it's like. Would Marvel Mystery oil be suggested right off the bet?! How long you have to let this stuff sit to hope for a positive change?!

Unknown history... bought the donor as a wreck... didn't seem to have any WVO junk in it at the time it was shipped to him.

Why is it 'Maybe Worse'?! Wouldn't a Turbo rebuild kit remedy this?!

I'm guessing a leak-down test would be needed to prove which of the valves is leaking, right?

__________________
1987 Mercedes 300SDL; SOLD
1985 Mercedes 300D; SOLD
2006 Honda Pilot - wife's ride; 122K;
1995 Toyota Land Cruiser - 3X locked; 182K

Could be multiple problems. Is the EDS controller communicating with the ELR actuator at the aft end of the IP? That controls idle speed. Failed head gaskets are unfortunately common on 602s. The timing chain of a 93 should hold up better than earlier 602s but maybe it's worn on this engine.

Sixto
87 300D

MMO ain't doin Nuffin for worn rings.

Some People have had "Luck" with H2O injection in the Intake "Curing" "Veggie"
stuck Rings.

As the expert (Sixto) says , Multiple causes could coincide to Obfuscate the
true cause(S).

A Leak Down (With A sidebar Compression Test) will Enlighten Y'all as to the
"Perp (S)".
[Consider,It may be the Valve Stem Seals and not the Valves themselves.]

(Translation: Y'all gots some Detective Work Ahead ,Before any "Treatments".)

__________________
'84 300SD sold
124.128

New Turbo Seals would fix it.

If it was Just Worn Rings ,I'd start running Straight 70 weight Racing Oil.
(That's a JOKE)

__________________
'84 300SD sold
124.128

Air in the fuel lines would cause rough idle but it wouldn't clear up much would it?

Uneven compression roughness would tend to clear up a bit as the car gets warmer so I have to agree there. Brand new or properly working glow plugs might tend to mitigate the issue I'd think.

The smoke, depending on what color, might reaffirm the poor compression and indicate rings as suggested. It could indicate too much fuel. How's the blowby?

__________________
Codifex
1981 240D ChinaBlue (Got her running with a donor engine.)
1983 300DTurbo w/sunroof.
1984 300TD manual sunroof. (Electrical Gremlins)

I don't suppose the '93 engine would need/require a valve adjustment?! Thanks - this gives me something to go on...

__________________
1987 Mercedes 300SDL; SOLD
1985 Mercedes 300D; SOLD
2006 Honda Pilot - wife's ride; 122K;
1995 Toyota Land Cruiser - 3X locked; 182K

I agree with everything thats been said... but start simple first : filters, fuel supply, lift pump, air filter

__________________

Nope. 1985 was the last year of manually adjusted valves. Everything after was hydraulic lifters.

__________________


~Michael S.~
Past cars:

1986 300SDL
1987 300SDL
1982 240D
1982 300SD


Current:

1987 300SDL

Having a 91 300D with 314,000 miles, and having had the exact problem I would suggest you check the glow plugs with an OHM meter. Should be about .1 OHM. When my car has a bad GP, it will run rough with ugly smoke out the back for a few seconds and then run fine. Another clue, when it has one or more bad GPs, the GP light will work just backward, off when it should be on and on when it should be off. However, it always starts. Best $1000 I ever spent.

Paul

__________________
84 500 SEL (307,xxx miles)

I can tell you that he USED to have this exact issue before we replaced the glow plug... after that the bad starting issues went away for a while, but now the glow plug light works just right but starting and keeping it running is difficult... We'll soon be checking filters, compression, and other things as mentioned above...

__________________
1987 Mercedes 300SDL; SOLD
1985 Mercedes 300D; SOLD
2006 Honda Pilot - wife's ride; 122K;
1995 Toyota Land Cruiser - 3X locked; 182K

Update: well, my friend came over with his smoking Benz on Father's day. We all had a picnic at a local lake - was fun.

Since the car sat in my driveway for about 5 hrs I was able to observe what it looked like starting out relatively 'cold'. He engaged the glow plugs for about 25-30 seconds then started it. It started out right away but was coughing and shaking from time to time. The tail pipe was emitting not blue but grey, white-ish smoke. It had a strong diesel smell, so I figured unburned fuel. Don't think it's coolant 'cause he's not losing any (he says).

It ran for a while, getting a pretty good shudder once in a while - every 30-40 seconds. It has a lot more clack than I remember from before. The smoke was visible until engine warmed up, then disappeared and exhaust was clear. After a warmup I had him rev it up hard: it was somewhat unresponsive to the throttle (delayed response) but when it kicked into high revs it would billow out a huge plume of black smoke now and then.

He finally told me he'd added some $hit to the tank - some kind of injector cleaner (I know know that detailed description of the $hit helps tremendously). I love my friend to death but his willy-nilly attitude about troubleshooting this car drives me nuts. I told him to run Molly Diesel Purge - he got some other $****... then he couldn't remember what the he&& this additive was called....

Well, white/grey smoke - I'm thinking unburned fuel, bad injectors?! I told him that he needs to fund an injector cleaning/balancing job. He's up for it.

What else - air in the lines?! Maybe since he'd added the $**** maybe it cleaned out the gunk from the bottom of the tank because every since he'd added it, the car started acting up. Maybe the gunk had plugged up the tank strainer and the lift pump is now struggling trying to get enough fuel from the tank and in the process, the air is getting sucked in somehow?!

Trying to make the most of this... thx in advance.
James

__________________
1987 Mercedes 300SDL; SOLD
1985 Mercedes 300D; SOLD
2006 Honda Pilot - wife's ride; 122K;
1995 Toyota Land Cruiser - 3X locked; 182K