Oil burning

[Bio}{azard]

Minor but annoying oil burning problem with my 231

Nearly every time I start the car a bit of smoke puffs from the exaust, and no longer continues untill the next time I start it. What could be causing it?

[TheSilentChamber]

Valve stem seals, when the motor isnt running its letting oil seep past the valves, when you start it the engine it burns off.

[Bio}{azard]

Originally Posted by TheSilentChamber

Valve stem seals, when the motor isnt running its letting oil seep past the valves, when you start it the engine it burns off.

Thank you, sounds like a lot of fun too

[TheSilentChamber]

depending on the car it may or may not be hard to replace. Some people use an air adapter that screws into the spark plug hole and keeps pressure on the valve so you can remove the spring and pull the seal out, put it back together, all without removing the head... also can do similar to that with a rubber band or zip tie, if its an interferience motor you may be able to position whatever cylinder your working on at TDC and rest the valve on the top of the piston.

[CBFryman]

^never seen/heard what TSC is talking about but as a general rule valve work=pita

not complicated, just pita.

However it needs to be taken care of, i let if fly on my kart for a few months and next thing i know im relapping by valve seats because of all the carbon build up

[TheSilentChamber]

You know valve steats are made to be reground....

[CBFryman]

yes, but it is a pain in the ass when all you have is a stick with a suction cup on it and some grinding compound.

They where fine the time that i rebuilt the motor before that (about 6months before ti started smoking) then it started smoking and i just kept adding oil instead of addressing the problem and 3 months later i had leaky valves and exaust comming out of the intake on idle and a milimeter of carbon build up on both valve seats.

[TheSilentChamber]

Thats not grinding, thats lapping.

[Fotheringay-Phipps]

Issue:

I just bought a used car that turned out to be an oil burner (approx. 1 quart in 200 miles). The dealer has agreed in writing to rectify the problem within 4 days. What I am concerned about is how I will be able to verify that the problem is fixed. He seems amenable to having a mechanic shop do a wet/dry compression test to ascertain the source of the problem, and to show me the results. What I am concerned about is the possiblity that prior to doing the test he will load up the car with high viscosity oil and additives, which might throw off the test results. My questions are:

Is this a genuine issue? (IOW, can a burning problem this severe be temporarily masked in this manner, such that a compression test will have misleading results?)
In general, what can I do to verify that the car is genuinely fixed?

Thanks!

[bluevp00]

Originally Posted by Fotheringay-Phipps

Issue:

I just bought a used car that turned out to be an oil burner (approx. 1 quart in 200 miles). The dealer has agreed in writing to rectify the problem within 4 days. What I am concerned about is how I will be able to verify that the problem is fixed. He seems amenable to having a mechanic shop do a wet/dry compression test to ascertain the source of the problem, and to show me the results. What I am concerned about is the possiblity that prior to doing the test he will load up the car with high viscosity oil and additives, which might throw off the test results. My questions are:

Is this a genuine issue? (IOW, can a burning problem this severe be temporarily masked in this manner, such that a compression test will have misleading results?)
In general, what can I do to verify that the car is genuinely fixed?

Thanks!

Sit there and watch the mechanic, make sure he doesn't do anything shady.

When the engine is burning that much oil, it's near impossible to cover it up, even with high viscosity oils or additives. Truth be told, the only way for your dealer to really fix the problem is to swap the engine with a different [better running] one, or to replace the piston rings.

[Fotheringay-Phipps]

Thanks a lot.

Are you saying that this much oil has to be the piston rings and cannot be the valves? I was hoping it was the valves. I can't imagine the dealer will be able to repair the rings for the amount of $ that he is getting for the car. My understanding is that the valves are relatively inexpensive, especially for a guy who has his own mechanic. So if you are in fact saying that this amount of burning rules out the valves as the culprit, please confirm this.

(Actually watching the dealer is not a practical option under the circumstances.)

[bluevp00]

It could also be the valves, but im thinking it's a combination of the valves as well as the rings that are letting oil past. Using 1 quart of oil every 200 miles is a huge amount as far as oil consumption goes, however replacing some of the valvetrain components might correct the problem. I don't think that a simple valve adjustment will fix such a huge oil burning problem.

The compression test will determine if it's the valves or the rings that are at fault (or both). Then you/the dealer can decide what to do from there.

[TheSilentChamber]

That much oil is not going to be valve seals leaking. Unless all the seals were removed and the valve guides are whored out.

[CBFryman]

that much oil the engine is running halfway diesle

[Fotheringay-Phipps]

The plot thickens. I just got a call from the dealer and he says he had his mechanic (an indepent mechanic but one with whom he does a lot of business) did a wet/dry compression test and it shows no oil burning at all - engine compression is fine. He is going to give me the write-up from that mechanic.

Now the facts that I know are that I changed the oil myself last Sunday and the next day it was about 0.4 quarts lower and the next day about 0.5 quarts lower. Saw this with my own eyes. Could I be wrong? My mechanic also identified an oil leak in the valve cover gasket (the dealer replaced this) but my mechanic insisted there is no way that amount of oil could be leaking from that source.

I think to be safe I should change the oil tonight to get rid of any possible additives or heavier oil (the dealer claims he used 10W40 and no additives) and then have another compression test done. But this dealer knows I've had a mechanic look at it, and knows I will bring it back to the guy. So I wonder if there's possibly some trick I'm missing?

The whole thing is weird.