HELP on '86 300SDL smoker

[Olbetsy]

I will be looking at a 1986 300SDL tomorrow with 235,000 miles on it. The guy says it’s a six that smokes whitish gray big time. Any ideas what I might be in for? Cracked head, head gasket or EGR valve?

[Brian Carlton]

Not the EGR valve.

Smell the smoke...........see if it's oil. You'll know right away.

If it is oil, there's a possibility that it's coming from the turbo. If you can get to the impeller after it cools down a bit, try and force it radially in the housing. If it moves any more than 1/16", the bearings are shot and there is a good chance that the turbo is the culprit. No great expense here..........maybe $500. or so.

Of course, there are other possiblities for oil consumption, and one of those is a bad head gasket around the #1 cylinder. If the turbo checks out, then this is the next possibility........but, the head must be removed to verify it.

Check it for blowby once it's warmed up. Remove the oil cap and see how much oil vapor comes out. A real good 603 won't produce any. A decent one will have a lazy column of vapor. A tired one will smoke like a train. If you find this condition, I would avoid the vehicle unless you can be positive that the oil consumption is not caused by the lower end of the engine.........impossible to do even for an experienced mechanic.

[Hit Man X]

Has the car sat for an extended time?

[Olbetsy]

Thanks Brian I check those suggestions out.

[Olbetsy]

I don't konw how long the car has been sitting, but the heavy smoking is constant.
Thanks Hit Man.

[Hit Man X]

Mine smoked like crazy before I started to drive it, the car had sit for around two years. It was as if the car itself was on fire.

[RAYMOND485]

1984 300d Turbo 136k
Remove The Egr Valve And Use A Hand Vacuum Pump And Use Carbon
Cleaner In The Valve The One On My Car Was Sticking, Binding, Smoke, Loss Power, Stop To Fuel Up It Would Close And Good Power
For 1/2 Mile Than Stick Open Again Lose Power Again, Also Did The
Valve Stem Seals The Kit Is From **************.com $75.00 Guide
Book, Seals, Tool To Install Seals, Extra Lock Nuts,install New Valve Springs Same Time $5.00 Ea =$ 50.00 2-6 Hrs Diy They Also Have Valve Adjustment Wrenches

[Hatterasguy]

Just from sitting these things will smoke like crazy for awhile. If you drive the heck out of it for a few days the smoke will go away.

Although it could be other things, Brian has pretty much covered it.

[t walgamuth]

if it is whitish gray then there are two possibilities.

first if it is steam then the "smoke" will vaporize and disappear pretty quickly. this means head gasket or cracked head.

bluish smoke can be either oil or unburned diesel fuel. oil is covered above in brians post. the diesel can be from a malfuncitoning injector.

so you will have to determine which kind of "smoke" it is.

if it is steam, that is the worst.

tom w