any and all advice is welcome in this matter as it is making me a bit nervous!

i just bought a 1985 240DL w/ about 200,000miles on the od. it has an automatic transmission and fuel injection. it runs great most of the time, however on occasion, usually at higher speeds like on the freeway or when at the bottom of a big hill when i really start to hit the gas, i hear a rattling sound from the engine (kind of like bolts in a tin can... valves maybe?) and i get a big white cloud of smoke out of the exhaust pipe. sometimes it only happens once, sometimes a couple of times. the cloud is pretty big and thick.

does anybody know if this is common and/or what usually causes it?

should i be worried?

thanks in advance for any help!

 

Not sure what could be causing that but I would definately take it down to a good volvo shop and have them diagnose it. It is better to spend a few bucks and get it fixed now than to blow your engine and total the car later.