Sparta00

So i just bought a 92 with a 5.0 V8 and i took it in for an inspection and tune up right? well ive had some overheating and some white smoke coming out of my exhaust while idling or revving. The mechanics told me that im burning oil thats what the smoke is and that my pistons are bad. I am hardly mechanicly inclined at all could it be anything else doing this or did i just get screwed into buying a lemon lol. Also how can they tell its the pistons without looking at them, I will be taking it to another shop for a different opinion feedback from people on this would be wonderful on how to rule those out and see if something else is causing this. im just not sure what to do im a bit angry since i paid 4k for the car.

Sonix

iTrader: (1)

It can be many things, but "pistons" are highly unlikely.

If it's burning:
oil - grey smoke - smells like burnt oil
fuel (too rich) black smoke - smells like gasoline
glycol/water - white smoke- smells strange, sweet.

How much smoke are we talking about?
Does it leak anything on the ground?
Have you kept an eye on the fluid levels and checked to see how much of each fluid is disappearing over xyz miles?

Finding out exactly which fluid is burning is first priority. After that, you can figure out where it's coming from. Ideally it'd be valve seals, or a PCV valve or something. However head gaskets could be bad, or intake manifold gasket, etc.

Piston rings - while possible, are a little less likely.
How many miles are on the car?
Keep an eye on your oil level and quality above all else.

Sparta00

my oil levels have been looking good and i have no noticeable leaks that ive seen anywhere i had an overheat earlier this week and it hasn't happened since but i also live in florida and its been really hot this month and stuck in traffic that day, the smoke is a grey/white smoke mileage is only 117, XXX the guy had also put a fuel additive in there a few months ago to keep the fuel lines clear while it sat, i have had no leaks on the ground either the oil lvl is good and its that clear yellow that full synthetic is supposed to be the smoke has a burning smell but it doesn't smell like a car burning oil i can't really describe the smell

Guest

When is it smoking? Cold idle? WOT? Deceleration? All the time?

Sparta00

Ok so the smoke is grey i took it to another guy and he confirmed it saying that it is in fact burning oil and it is possible the piston valves or something of that sort the car only smokes when idle on and off it smokes big puffs when i rev it and it smokes when i acclerate i just want to know if there is anything else besides these as its an expensive fix and if it is the pistons should i rebuild or get a new engine all togethor any thoughts please, also if i run the current engine while its burning oil what effects will this have on the vehicle

Sparta00

also i checked the oil this morning the lvl was fine and its the color synthetic oil should be also i want to add that the previous owner had the car sitting in his driveway for about 6 months and told me in feb he emptied the gas tank and put in some type of additive to keep the fuel lines from getting gunked up while it sat. could it be this crap burning off ?

fireturd350

iTrader: (8)

Could be bad valve stem seals. The seals are on the top of the heads inside of the springs. Cheap fix if that's it but takes some time to pull it apart. I don't know if I missed it, but when is it burning oil/smoking? It's probably not the fuel stabilizer.

Confuzed1

iTrader: (4)

If you have a compression checker and know how to use it, it's easy to nail down whether it's valve seals or rings. All plugs removed (coil plug disconnected) and a fully charged battery, screw in tester and allow to pump 3 times. On the 4th spike take your reading.

Unscrew tester, and add in 1 teaspoon of oil in spark plug hole. Do same test on same cylinder. If pressures increase it's the rings. Done - move to next cylinder.

EDIT: A cylinder leak-down tester is used to determine bad valve guides and is a more involved test.

Sonix

iTrader: (1)

Yea, if it smokes when revving or when under power, it'd generally be rings. Not much you can do about it.
If it sat for 6 months + without an oil change, I might recommend starting with that. If the car is new to you, i'd also check the spark plugs (totally unrelated, but good to check).
I'd run a few tanks of gas through it, and determine how much oil it's burning per tank.

I also like to do a "top end clean" on a car that's new to me. Especially an older car, or one with ~>100,000mi. I just run a ~10' long piece of ~3/16" vacuum line from a "spare" carb port (or FI-vacuum port in your case), into the car, and cap it. Get the car good and warmed up, then climb a good long hill under heavy power, and get your helper to stick that hose into a jug of water, to get some water into the combustion chambers. It essentially steam cleans it. I run about a gallon through it. I also put some ATF into my first oil change, and run that for ~500mi, then change it again to flush out the crankcase. Also, you can run a fuel system cleaner (seafoam or alternative) in the gas tank.

Sparta00

I have had the car for about 2 weeks now and have ran about 4 tanks of gas on it and to be honest the oil lvl has remained the same when i check the dipstick so maybe i will just change the oil and see what happens i may just say screw it and drop an engine in with more horsepower anyway 170 is nothing and i don't like the idea of rice burners beating me at stop lights if it was burning oil though would my lvls be going down everytime i checked it with the stick, someone at work also told me when i change the oil smell the old oil and look to make sure it isn't black or smells burnt and also to see how much drains out.