My old, smoking car

My car has 343,000 miles and runs great. It has recently started smoking, but only does it when the engine is cold. I’ve heard that it could be the rings, and to buy an additive that I could add to the oil. I go through about a half a quart for every 500 miles. I’m not expecting the car to last forever, but I was wondering if it would be beneficial to buy the additive.

I’m not a big fan of additives but at 343K you could try one can of STP right after an oil change. If it works…it works. If it doesn’t then 1 quart every thousand miles is pretty good.

Aside from a total engine rebuild…if you wanted to try an additive…which is really just a waste of time with this many miles…the only additive I would try is ENGINE RESTORE…I believe it comes in a silver can…one for 4cyl and a bigger one for V8’s. This is the only product that actually has solids in it…the solids melt and then find there way to ring grooves and fill them in…“supposedly”. Any other product will not be able to compensate for the amount of wear you have on this enigne…because you do have wear. If it works it works…if not then you just found out the wear limit on that engine…BTW That car/engine owes you ABSOLUTELY NOTHING anymore.

Back in the day we would put 2-3 quarts of GEAR OIL in the engine…this is thick and clingy oil…if you rub it between your fingers it will produce strings when you pull your fingers apart…

If you live where the temperature is usually above freezing except for maybe an hour or two overnight, straight 30wt will stop the smoking within seconds of startup. You may not need all 5 quarts to be that thick. Try three. It’s cheaper than any additive.

I do not believe any additives will do any good. I’d try the straight 30wt oil instead. you can also look for a used engine for the car. Depending on the make and age of the car you may be able to find one for $500 or $600 plus installation.

If it only smokes at start-up, the problem is most likely cracked and hardened valve stem seals. They allow oil to drip into the intake and exhaust ports of the heads when the car is shut-off. This oil burns off when the engine is restarted the next morning, causing the smoke.

Try some oil leak additive that softens oil seals or try a ‘high mileage’ oil at the next oil change that already has the additive in it.

If it is the rings, the smoking will not stop as the engine warms up.

If it’s only burning at startup…it may just be the valve seats. But if you’re going through a quart every 500 miles it’s most likely the rings. As the car warms up it’s burning the oil more efficiency so you won’t see it as much.

You can try an oil additive like STP or restore. But it’ll only mask the real problem and slow down the eventual death.

Thats TRUE of it is at startup…But the smoke you will see will be more gray…than blue I believe if it is valve seals.

Quite a few companies make valve seal softener…look them up. Could work…WILL work if thats the source of it… If its rings…its time to rebuild or re-buy

Just to clarify matters, MikeInNH is referring to the valve guide seals, not the valve seats.

With 343,000 miles and burning only a quart per thousand, just keep driving and keep oil in it. Nothing else is cost effective.

I agree. A Corolla with 343,000 miles has earned the privilege to smoke a little bit. It would be as bad to try to get your Corolla to quit smoking as it would be to take the cigarettes away from a person who has lived to be 98. Let your Corolla go its last miles in peace without giving it additives or heavy weight high mileage oil.

You can try some of the additives talked about here, but why? I assume the engine runs fne, does not foul spark plugs, or have any other issues, right? Just top-off the oil once in a while and you’re good.

You could go out and buy a brand new car and have it use a quart of oil every thousand miles.

ive used the Engine Restore and it works great and doesn’t vacuum your wallet lol. we’ve got them in French (remetalissant) and German (Motor Kur) over here but its the same inside. Restore sells in 28 countries.
here’s a discussion on utube:
and they’ve got the support in the USA of Ivan Stewart (off road champ)

Not sure of the year of your Corolla, nor the weight oil you are using currently. Assuming you are using 5W-20 then a heavier weight oil will help. If you are in a cold weather area stick with 5W for cold starting oil flow, but go to 5W-40 or 5W-50 for less oil burning when the car is warmed up.

In the warmer summer weather you could go to straight 30W or 10W-40 or 15W-40 to see if you have less smoking at start up. Smoke at start up really isn’t a big deal to me. If the smoke is still there after the engine is warm, that is more of a concern. Adding a quart of oil every 1K miles isn’t a big deal especially in an older car with 350K miles.