I'm looking to buy an 87 SDL and I have some questions that I hope someone will be able to help me with.
First here is some info on the car. The car has been sitting for some time. i dont now excatly for how long, perhaps a month. Body is in excellent condition, it has been serviced at a MB dealer for most of its life.There's a leak in the fuel line under the drivers seat. fuel flitters, dont appear to have been changed in some time. The primary fuel flitter looks black inside. Engine starts fine but emits white or white-grey smoke very faint.
I've been searching and reading previous threads on the 603 engine and I am concerned about possible head failure. The whitish smoke is faint but did not disappear even after driving for 20 minutes. Reving the engine only produces slightly more then at an idle. The engine temperature did not exceed the low 80's, even after idleing for some time. There is no oil, in the coolant reservor. After running the car for about half and hour the upper rad hose was hard, and then after letting it sit for 30 min, the upper rad hose was soft.
The engine idle varies. It idles normally then drops down to just above a stall. At no time did the engine stall, even when driving.
Now to the questions!
1. Is the small amount of whitish smoke an indication of possible head problems, OR something else? contaminated fuel, fungus, fuel leak
2. Could the idle be a large electrial draw? Fuel related?
This is my first diesel, and any help would be gratefully appreciated.
Frank

Brian, where are you???????

The guy that knows SDL's can answer your questions better than I. I have the 87 300D, which also features the very same 603 diesel. Everything sounds good except the obvious white smoke and rough idle that you mention.

I too would be concerned and I'll try to help. White smoke can also be associated with fuel system supply, including fuel filters, injection pump, and injectors.

Other possibilities may include, but not necessarily include a bad head gasket leaking coolant into combustion, or even a cracked head, worse case.

You mentioned checking hoses and the only thing that I'm not real sure about is a deflated hose 1/2 hour after shut down....Seems to me that mine stays hard for at least a couple of hours, the time it takes the engine to cool down. Still this doesn't mean anything. Just a thought!

So, no coolant loss, no oil in the reservoir, no hard hoses after 3 minute cold start?

Running rough, or up/down idle may have to do with algae-up fuel filter, and even a dirty air filter....my mileage goes up when I put a new air filter in.....so there are several possibilities for issues unrelated to the cracked head syndrom............Only about 20% of original heads are known to crack...............to buy or not to buy............How much are they asking?

If the car has been sitting a while, its possible there is moisture in the fuel and engine intake. This could produce some white smoke/steam but once the car has been run for a while it should go away.

You really need to run the car for about 30 minutes then leave it overnight to try the Rad Hose to check if it is hard or soft. A Head (or head gasket) leak will slowly pressurize the cooling system.
The fact that there is no sign of oil in the coolant is a good sign, but did you check the oil for signs of coolant?
If the car checks out otherwise I would recommend a longer road test and if possible a pre-purchase inspection by a M-B specialist with a compression/leak-down test. Its worth the money for peace of mind.

The rough idle could be a number of things, but probably not electrical unless the A/C compressor is loading it up or the A/C Clutch is misbehaving.

__________________
1991 M-B 560SEL Arctic White/Grey 99,000 Miles
1987 M-B 300SDL Ivory/Palomino 229,000 Miles (sold but never forgotten)
2006 Volvo XC70 Blue/Beige
1999 Porsche Boxster Arena Red/Savanna Beige
1986 Porsche 928S Goldweiss/Brown

Mine smoked hardcore before I got to drive it... it had been sitting for over a year. Inspection on mine was last done in March of 2003... last oil change sticker was from April 2004. So I presume he sat between May/June 2004 to July 2005 when I picked Karl up. It would smoke even more when giving it some fuel at idle. After about 30-40 minutes of driving it went away.

I did check for the obvious stuff such as oil in the coolant or vice versa, and the timing chain still there as I bought it without driving it. Big risk I know. Yet I did find receipts for lots of PM in the past, new starter, new glow plugs, etc. So it was worth it to me to throw the dice.



My idle was messed up due to the ELR being plugged in backwards. Apparently the IP is controlled electonically. There's a small knob up by the fuse panel so you can try to turn it and see what happens. Mine just took a quick flip of the wrist to fix.



Do the vac locks all work? Sunroof? Turbo spool up and seem to operate? Trans shift properly?

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

I'm just curious, but where does the pressure generate from that will pressurize the cooling system overnight?

I wouldn't be concerned with very faint gray/white smoke on a vehicle that has been sitting around for a lengthy period of time. The 603 can get thoroughly clogged with soot if it is not run hard very frequently.

On mine, I saw it blow out a cloud of smoke after it passed 4K rpm and it continued on up to 4400 until I let it shift to fourth. And this one gets a good highway run every week.

If you can go back to the vehicle the next day and squeeze the upper hose, it should feel soft. Also, take a careful look in the expansion tank and make sure there is no oil in there.

The idle on the SDL is maintained by the computer, independent of load. It's adjustable via a dial right on the firewall, and, typically the engine is set quite low.......about 630 rpm. However, if the system (EDS) is working properly, the idle speed is maintained without regard to the a/c or any electrical load. So, if it is hunting, there is definitely an issue with the EDS or the injection pump.

If you can arrange it, a proper prepurchase inspection with a compression test will tell you the condition of many items on the vehicle. It's difficult to make a solid judgment of a smoke condition by wire and we wouldn't want to steer you wrong.

As I understand it the compression in the cylinder(s) that is there even after the engine is switched off (unless valves are open of course) can find its way through a leaking head or gasket into the cooling system and pressurise it.

Thanks for everyones fast replys.I'll try to fill in some blanks.
209k miles, asking $5900 CAN,tranny shifts smoothly,vac system working, MB replaced oxidizer and turbo.
I too thought that a rad hose would have stayed hard longer than 1/2 hour but it didn't.The motor was up to operating temp.
I did check the dip stick for water but it looked normal.Is there another way to chech it short of draining the sump?
I really like this car so I think I'll find someone to do a leakdown test,
Thanks again for your help. If you have anymore comments please post away.
Frank

Where are you located?
Maybe someone here can recommend an independent specialist in your area.
The price is certainly reasonable if the car is in good condition.