Checking out a 85 380SL

[shane83SD]

Not familiar with MB V8 gas cars, appreciate your kind feedback.
I had a brief test run of a 85 380SL. It has this solid feel, accelerates well.
Here are the obeservations/problems:

1. Idle seems high (750RPM). When blippiing the gas pedal at idle, blackish fume is observed at the tail pipe. Seems running too rich. Did this couple times and engine died. However, have no trouble re-starting it.

2. While idling, put my ear close to the valve cover, can hear faint valve tick. Good? Bad?

3. When accelerating or de-celerating, there is a metal clunking sound from the mid bottom area. Only clunk once per accel or decel. Strange.

4. Paint is shot along the side panels, but not trunck lid and hood. Rather strange. Different paint from the factory?

[jim16671836]

Put the car on a lift and then try to shake the main drive shaft.. If you can shake or move the shaft then this is your clunking noise. As the carrier bearing rubber Isolator continues to wear out the clunking will become 2 and then 3 and then 4 clunks etc..
The valve ticking can just be a matter of changing to synthetic mobil 1 oil and adjusting the valves...
If the car has mileage over 120K then I would pull one of the valve covers and check to see if the timing chain is a single or a double...the double will last a lot longer than the single and when the single gives up, you don't want to know the rest(it can be horrible).
It sounds like the trunk and hood have been repainted. Does the car come with clearcoat????Usually the hood and trunk deteriorate faster than the side panels due to heat and the hours of direct sunshine. JIm

[Scott]

The 380 SL is fun to drive, but not the best running car I own. I hear a slight valve tick too.

[KirkVining]

If it looks like the instrument cluster has been changed out on it, I wouldn't trust the miles. You may be getting into a lot more than you bargained for. I would get a compression test done.

At this point just about any SL from the 80's that has been a daily driver is going to have been repainted at least once. I bet the re-paint job is peeling - body shop applied paint usually sticks better on the horizontal surfaces than the vertical.

[shane83SD]

I think the side panels may still have the original paint, and is oxidized now. I do not pay too much attention to the "indicated" mileage but the condition of the car is where I'm looking at.

I think the fuel system is not quite right (black exhaust) and it'll die while blipping the throttle. It did passed the CA smog test several month ago, but the NO reading is near the high mark at 15 mph test.

I think the owner could'nt keep up with the proper care for the car. I'm not very confident with my skill regarding to MB gas V8 to bring it back to tip top condition. It is an intimadating thought that I need to hone my MB V8 skill on a 107 SL.

[ctaylor738]

The 1985's had a mod to the injection for better enrichment on acceleration, and this may have gone south and is over-enriching when you blip the throttle.

750 RPM hot idle is high and could be a failing idle air valve, the idle relay, or a bad coolant sensor, or a wiring problem. Or it could be a vacuum leak or bad injector causing a lumpy idle, so the coolant sensor leads were bridged to keep the idle high.

The valve tick is probably a rocker arm starting to wear or a hydraulic element in the ball stud starting to fail. You might be able to clear it up with a couple of oil changes and there are some flushes that sometimes work. It needs to be attended to promptly because it can lead to cam damage, which is expensive.

You have to buy this car right because the resale market is ruthless for cars with obvious problems. There are too many nice cars around.