some problems with 1979 450sl

[ac12491]

hey everyone,
i was just wondering...

a good friend of mine sold me his 1979 450sl a while back and i haven't had alot of time to work on it until recently. the car drives with what i hope to be some minor problems including:

-when i start it up and drive it, everthing seems fine, but when the engine warms up and its idling(stop sign or traffic light) the oil pressure drops, engine idles at very low rpm, and usually engine stalls, but once i accelerate the pressure goes back up. (to help it to not stall when im at a stop light, i switch into neutral and rev the engine a little to keep it just below 10)

-engine seems to run very hot. im scared it will overheat

-when i start the engine after it has cooled down, ALOT of exhaust smoke comes out of the exhaust pipe. when the engine warms up then not as much smoke comes out.

if i could get an answer to some of these problems it would be great. thanks guys!

[ctaylor738]

You can try adjusting the idle with the giant screw in the middle front of the engine. Turn it clockwise a bit and see if that helps.

You might also check the timing.

If the low idle is lumpy you could have injector or fuel distributor problems.

The smoke could be valve seals/guides.

[ScottinSoCal]

Originally Posted by ac12491

-when i start it up and drive it, everthing seems fine, but when the engine warms up and its idling(stop sign or traffic light) the oil pressure drops, engine idles at very low rpm, and usually engine stalls, but once i accelerate the pressure goes back up. (to help it to not stall when im at a stop light, i switch into neutral and rev the engine a little to keep it just below 10)

Adjust the idle higher. Big screw in front of the air filter housing, a little to the right of center.

-engine seems to run very hot. im scared it will overheat

Where is the temperature on the gauge? Anything from 175 to about half way to the red is normal, depending on driving conditions.

-when i start the engine after it has cooled down, ALOT of exhaust smoke comes out of the exhaust pipe. when the engine warms up then not as much smoke comes out.

What color is the smoke? White? Black? Blue/grey?

[ac12491]

ok thanks a ton guys. i'll try to adjust the idle and let you know how it goes. ctaylor738 im not a major mechanic but is checking the timing hard? scottinsocal the smoke is white, and what happens is when its coming out and you walk to the rear of the car you can hear a sound coming from the exhaust pipe kind of like a "sssssssss" sorry i dont know how to really describe the sound...

[roncallo]

Originally Posted by ac12491

ok thanks a ton guys. i'll try to adjust the idle and let you know how it goes. ctaylor738 im not a major mechanic but is checking the timing hard? scottinsocal the smoke is white, and what happens is when its coming out and you walk to the rear of the car you can hear a sound coming from the exhaust pipe kind of like a "sssssssss" sorry i dont know how to really describe the sound...

Unfortunately that sounds very much like a head gasket or head. I wouldn't drive this until you have it checked out.

John Roncallo

[Nascar Fan]

Turn it clockwise a bit and see if that helps.

Are you sure about this. Counter clockwise would allow more air. It's early, so pardon if I
'm mistaken.