Hi there - 1980 320is

[WrenchRat]

hi,

i got my car for 500 bucks from a guy who didn't know how to change a tire. the sparks were fouled up so badly the gap was almost gone. the spark cables could barely hold onto the plug - they were busted and threadbare. the O2 sensor was black with charcoal. the thing still ran on the interstate - these engines are amazingly tough.

so i replaced the junk stuff, change the oil, and it runs so smoothly now. but the idle won't stay still after it starts up. it oscillates between 500 1100 rpm until it gets nice and warm, then it steadies out around 900. why does it do that?

see you all round the corner!

[witeshark]

That's awesome so far, best of luck on sorting the rest!

[WrenchRat]

thank you!

while i was working on fixing everything so far, i noticed some oilyness on stuff between the engine and the cabin firewall. i wasn't sure what this was so i just left it alone and bought soem degreaser to clean it all up. but before i could do that, Im driving it on the highway and it suddenly starts to lose power and sounds like a motorcycle.

i pulled over in a shopping mall and left it there to cool down. i'll bring it home tomorrow. but it seems like the oil on the firewall was coming out of a small gasket leak in the head gasket, and it finally turned into a gaping hole in the gasket. so i'm going to pull the engine and replace the head gasket. i hope that is all that is wrong with it. it was literally on the way to get it to the smog station!

and i think it is running much smoother with copper sparks than platinum.

i'll post with an update after i get the engine out.

[witeshark]

I would check carefully for the oil splash. The motorcycle noise tells me something about the exhaust header/manifold gasket.