I just recently bought a 1982 380sl, so far I love this car, but I'm having small (which might be major) issues with the engine. It runs very good above idle, but at idle, was running very rough. The car was in storage for about 7 years and does have over 150000 miles on it. At first I thought it was just the old fuel, so I changed out all the fluids, and added Seafoam to the gas and ran the tank down to 1/4 and added fresh fuel. It seemed to improve, but still ran poorly at idle.
The P.O. stated he did a tuneup on it, but I think he ment 7 years ago, so I changed the plugs and found they were very old looking and one plug looked like it wasn't firing at all. So I did a compression check. It read 60 at idle and did increase with exceleration up to about 110/120. I figured either the valves are carboned up or the rings are gummed up from sitting so long (at least that's what I'm hoping).
I added some more Seafoam and Lucas engine cleaner and have been trying to drive the car on the expressway as much as I can to try and clean or free up the valves and rings. It does seem to be improving at idle and runs great at speed.
Does anyone have any other suggestions on how to clean the rings and valves and also freeup the rings. I know an engine overhaul would solve all this, but I don't have that kind of money at this time and to be honest, the engine runs great, but just idles poorly due to the one cylinder. I'm hoping that freeing up the rings and cleaning the valves will solve the problem. Also, it doesn't burn or leak a drop of oil, so I do believe the engine is in fairly good shape.
Any one have any other suggestions on what type of engine conditioner to use. I've read about ENGINE RESTORE as a possibility.
thanks