jpc647

Alright Folks, I've got a 1972 Cutlass "S" with a factory 350 and 4bbl carb. I've had the car for about two years and have a unique problem. It seems to use a lot of oil, but it doesn't burn it, or leak. Once in a blue moon there is a little spot underneath the car, but not very often. I don't beat on the car a lot, but it seems to go through a quart or two between oil changes. Burning this much oil, I would think the car would smoke, but it doesn't. Even under full acceleration there is no blue smoke out the tail pipes. Is this common? I run Mobil 10w-40 for oil. Any suggestions? The car runs good and starts right up, never had a problem with it.


Car wasn't leaking or burning oil. Was a small leak in the back of the aftermarket intake that came on the car, allowing oil to squirt out near the distributor, and was burning off from the heat of the exhuast or whatever.

Fixed this long ago, just editing my OP for reference.

Warhead

How many miles on the engine?
*****Important...Have you checked the plugs?*****
Is the car oily underneath?
There is only so many places the oil will go.

JMO
Jim

jaunty75

You don't say how many miles you go between oil changes, but consumption of a quart of oil every 3000 miles would not be considered excessive. Two quarts, yes. But not if you're changing every 6,000 miles. As was asked by Warhead, how many miles on the engine? If it's anything at all, you've got a high-mileage engine that uses some oil. Very normal.

But look at the engine closely underneath. Just because the oil doesn't drip on the ground doesn't mean it isn't seeping out of a million places and coating the underside of the engine and then evaporating. I had a '75 Chevy Nova once that, after about 50,000 miles, looked like the underside of the engine had been dipped in oil.

jrsixx

but consumption of a quart of oil every 3000 miles would not be considered excessive

Heck by new car manufacturer standards, 1 quart per 1000 miles is normal!

jpc647

I usually got about 2500 miles between oil changes, give or take a little. The bottom of the engine, pan, or underneath of the car does not appear to have any oil or oil remnenace on it. But the car doesn't appear to burn it either.

Warhead- I will check the plugs tonight, I was busy organizing the new garage last night, and the toold were buried under piles of stuff. The engine has I believe 141,xxx miles on it. As far back as I can go with previous owners, no one drove it much. It is possible it is 41,xxx original miles, but I'm not assuming that. I've driven it the most out of anyone the past 15 years.

jaunty75

I think you have an engine that just uses some oil. An engine with 140,000 miles on it will do that. It's normal. It doesn't burn it enough to make the exhaust visible, but it is certainly apparently burning it as you have no leaks.

But it is not excessive consumption, and putting a quart of oil in every 2,500 miles isn't a terribly large expense compared to tearing down the engine and rebuilding it. You might want to do that at some point, of course, but this isn't a reason to all by itself, in my opinion.

jpc647

Thanks. I'll have to watch it, I know the otehr day I put a little over a quart in and now its full. I'll watch it. I thought I already added a quart this oil change, but I could be wrong. I feel like if the car was burning more than a quart or so I would see it smoking on a regular basis, right?

jaunty75

You're talking about rate of consumption. I'm no expert, but I think that those cars you see sometimes putting blue smoke out of the tailpipe constantly and smelling awful are burning oil at a huge rate, like maybe a quart every 500 miles or less. In other words, I think your car would have to be consuming oil at a much higher rate (five or six time the rate now) before it would become visible in the exhaust.

lshlsh2

I had a 307 in a custom crusier that burned 5 quarts in 1200 miles. Never saw any blue smoke never any oil under the car. Car was under warrenty so I told them I wanted a four-stroke engine not a two-stroke. They found the problem was a crack that let oil into the intake where it vaporized and was burned evenly drove them nuts trying to find the problem. A new moter was installed at no cost. Never had another problem with that car I wish I still had it.

Larry

jpc647

Wow... Yeah, I'm hoping I don't have a crack in the intake. It's an aftermarket intake thats probably ten years old, so one never knows.

Lady72nRob71

My 72 also has the 350 4bbl with 155K+ miles. It burns about 2qt of 10W-40 in 3000 miles.
Engine hasn't a trace of oil on its outside, so it must be drinking it. No smoke at all though.
My Caddy burns about the same about of 10W-30 (85K miles) and I hear that is somewhat normal for the northstar. Seems crazy for a "new" car, but I have to live with it - those engines are not rebuildable in my opinion.

For now I will just add a quart to the Olds at 1500 miles and change it at 3000.
I will save the rebuild for WAY in the future...