I Need Help In A Bad Way!!

[Matt_ks]

So this past weekend I bought a 82 chevy pick up with a small block 350. The problem is it smokes. When I leave a stop light it leaves a gray cloud behind, and as in driving down the hiway it smokes like a 2 stroke motor, but it dont smoke on start up and while its idling. The guy I bought it from swears its just the valve guides and seals, but my father-in-law says its the rings. the kid also says that he had two mechanics look at it and the believe that its the heads also!! CAN u guys HELP???? I dont want to buy a new motor if I can just change the heads!!

[chevy72blu]

Originally Posted by Matt_ks

So this past weekend I bought a 82 chevy pick up with a small block 350. The problem is it smokes. When I leave a stop light it leaves a gray cloud behind, and as in driving down the hiway it smokes like a 2 stroke motor, but it dont smoke on start up and while its idling. The guy I bought it from swears its just the valve guides and seals, but my father-in-law says its the rings. the kid also says that he had two mechanics look at it and the believe that its the heads also!! CAN u guys HELP???? I dont want to buy a new motor if I can just change the heads!!

What do the spark plugs look like? Can you run a compression test?

[ChevLoRay]

There are a lot of "rules" when it comes to smoke. If you are seeing it in the headlights of the vehicles behind you at night....it's hard to say what it is. It could just be a rich fuel mixture. If it puffs out the tailpipe when you start it up after it has sat all night, it could be valve guide wear. That means that oil leaks down the stem of the valve from the top of the head and has accumulated in the top of the cylinder. It then burns up at engine start and smokes at that time. My wife's Lexus does a little of that in the morning. It doesn't bother me. If the smoke is white, it could be water vapor, meaning it shows up as steam, so to speak. Oil smoke is blue, fuel mixture is usually greyish but may be black if it is really rich. White is (as I said) generally water vapor.

Seeing "smoke" when looking in your rearview mirror at night may not be a biggee. There are those who will tell you that doing a valve job without getting deeper into your engine will improve the vacuum to the point that it starts pulling more oil from the engine into the combustion chambers and burning it....so more blue smoke all the time.

Run a compression check. See how your engine looks in that respect. If the pressures are within limits, and you aren't using more than a quart between changes at 3-5K miles, I wouldn't worry about a thing. If seeing that haze behind you bothers you, get rid of the mirror or don't drive at night. If you aren't fouling plugs, what else do you want to find wrong?

[Matt_ks]

I know its in fact oil that is burning!! but does it sound like heads or is it deeper?

[Matt_ks]

I havent pulled the plugs yet im kinda affraid! LOL

[ChevLoRay]

Originally Posted by Matt_ks

I know its in fact oil that is burning!! but does it sound like heads or is it deeper?

In order for the oil to "burn" it has to get from the pan to the combustion chamber. An internal combustion engine is first, and foremost, an air pump. It takes air (and fuel) in, applies heat (a spark) and the compressed mixture exits the engine (the pump). Of course, there is power created by the process.

So, the vacuum created by the exiting exhaust can pull an oily vapor from the crankcase, in a worn cylinder, past the rings and into the combustion chamber. Does this mean that you have a worn engine? Probably. Does it mean that you have a worn-out engine? Maybe. Chances are that as long as it has enough compression to start on its own and isn't laying out a fog like the kind you see on a mountain top, and you aren't adding a quart of oil a day, you are not looking at having to put an engine in it next week. Does it mean that you can drive it like you stole it? Depends on how quickly you want to replace that engine.

How old are you? Is this your first truck? What people told me when I was new to this driving business is "you can buy a whole lot of oil for what it will cost you to rebuild/replace your engine".

[HavinSomeFun]

Replace the PCV valve first. It could be sucking oil into the carb and creating the smoke. It that doesnt fix it then the rings are shot.