red70stingray

I bought a 69 vette a few months ago with 150k miles. Car ran nice so I decided a full tune up and an oil change. Now the car is a smoking mess, it leaves white smoke every where , idling and upon acceleration . What did the previous owner put in the oil to hide this problem during the sale?

AkrHack

I used to work at a used car lot back in the day and the car lot owner would buy a product named "Motor Honey" by case. It increases the viscosity of the oil in the crankcase in order to stop high mileage engines from smoking. Perhaps the PO of your Corvette used a product like this in your car.

dar322

well at least its not blue smoke. i had a transmission modulator valve go bad on me. White smoke everywhere. check your anti-freeze.

tokim

White smoke, typically is caused by a blown head gasket, cracked head, etc. Is the oil milky colored?
People use products such as silverseal, Barsleak, K&W Block Seal, etc. in an attempt to solve these issues.

John485garage

time for motor overhaul, you'll be just hiding the problems with those sealing products. crate motor would be the way to go.

AdamMeh

Little early in this process to be spending money on a new motor. Find out what's going on before you throw money at the car, but do check this out before you drive it again. If it is an internal coolant leak and is bad enough, you could hydraulic a cylinder and that never ends up well.

Rent / buy a block tester and see if you have exhaust gases in your coolant. Very simple to do and cheap. You can rent them from some of the auto parts stores like Orielly and / or Auto Zone. Here is a Youtube vid that shows the test being done. I think it was about $10 for a bottle of the fluid, and you'll get your money back on the rental tool as long as you return it undamaged. There are better vids about this, but this shows what you are looking for quickly
Check your oil. Is it clean, or as mentioned above a milky color? Is it over the full mark like antifreeze has added to the volume?

Are you sure it's white smoke? Do you have a sweet smell from the exhaust?

What do your plugs look like? Do any of them show an indication of coolant in the combustion process?

If the smoking is as bad as you say, it seems unlikely that an additive was masking that. More than likely it's coincidence in the timing of changing your fluids.

Let us know what you find out on the items above.

Adam

Easy Mike

Possibly nothing. White smoke is often coolant burning, a condition which could have occurred after you purchased the car.

lurch59

Well, a small block chevy with 150k miles needs a rebuild anyway. The good news is they are cheap and easy to rebuild....

red70stingray

The oil is clean, I have been checking for the white foam build up and there isn't any. I also have not lost a drop of coolant. I did buy this car because I have multiple show cars covered in the garage and I bought something I can actually enjoy and not go down the same road the others brought me. I will see about thickening up the oil with additives, and i'm going to continue to drive it hard and have fun!!! when the motor blows, then i'll replace it, till then i'll try and hide the motor smoke with my tires burning up smoke!!!!!

Billem

Another possibility is bad valve seals. You could do quick check for bad seals by taking off the valve covers and seeing if there are "hard, plastic parts laying atop the head". Turns out, in my case, the "hard plastic parts" were crystallized (sp?) umbrella seal remnants. Everyone have a very Merry Christmas, Bill

TEXASDESERTVETTE

One morning I had white smoke coming out of the exhaust pipes... At first I thougth is was transmission fluid pucking out of the dipstick tube... Then possible coolant loss... Turned out to be a stuck closed butterfly choke...disconneted it and unjammed the butterfly's ... "She" still runs "Fine and Dandy". Some will say "Bull-Hocky"...but it "Was what it Was"

phat87

There is no thing as an EASY way to do valve seals. But some are easier than others.

If you don't have oil in the water or water in the oil I would suspect the valve seals.

Just out of curiosity what weight oil did you put in? ( old engines like straight 30)

The13Bats

I love the range of viewpoints and opinions in this thread,

I believe some pieces are missing from this puzzle,
While a 150 miles screams rebuild time to some, if the engine was maintained well it could still have many more miles of life as a fun driver,

I have seen people use all kinds of "engine honey" but never seen it get rid of 100% of the smoke,

The OP says the car ran fine and while I wonder why fix what isn't broken he did a tune up and oil change,
When I read that my first thought was what did the owner do to cause this,
Like TEXASDESERTVETTE says and I agree it doesn't mean yet the engine is toast toss it out it could be some silly little something.

Start with a compression check, if that checks out then you likely just mucked up something when you tuned it....

dugsgms74

Is this a auto or manual trans car?