Thread: Engine Smokes

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So i bought this 85 chevy and the motor smokes when there is a load on it. i know its most likely the rings are fried but do you guys have any other ideas what might be causing it ti burn oil and smoke

PCV system could be doing it.

Do you have a baffle on the underside of where the PCV valve plugs in?

Might want to check compression as well.

Anything that is supposed to keep oil out of the combustion chamber could be suspect.......rings, valve guides or seals, etc.

There was just a thread on another forum where a guy swears he stopped an old car from smoking by putting Bon Ami cleanser down the carb and it stopped burning oil! He said he put a small amount of cleanser into some gas and slowly poured the solution down the carb as the engine ran, and the cleanser "honed" the cylinder walls and rings enough that they seated.

I am not recommending it, but if it is a high milage car that you just want to get some more time out of.....................

BTW, he suggested changing the oil immediately after so that any cleanser that gets past your rings into the oil wouldn't hurt the bearings, etc. I don't know if it works, I'm just reporting.

Here is what he posted:
______________________________________________________________________

20 coca cola bottle, cleaned w/ carb cleaner
1 tablespoon of powder
the rest 89 octain unleaded.
Shaken not stirred ( just had to say that)

ran the car at aprox 2000 - 2500 rpm
fan to the radiator
poked small hole in side of bottle
dribbled solution into carb over a 10 - 15 minute period

Adverse affects = NONE
Smoke = NONE
had to adjust idle up aprox 1/2 turn (compression rising???)
Sounds better (isn't that scientific)
let it Idle for a minute

Shut her down, gonna let her cool, then test drive for the scientific seat of your pants test.

I will repull compression after she has cooled back down to the same temp as the first test.

Stay tuned.......



Then he updated it:

_________________________________________________________________________

every cylinder is AT LEAST 15lbs higher than the first test.

BEFORE
cyl 1 70 lbs
cyl 2 70 lbs
cyl 3 73lbs
cyl 4 71lbs
cyl 5 70lbs
cyl 6 74lbs

AFTER
cyl 1 85 lbs
cyl 2 87 lbs
cyl 3 86lbs
cyl 4 86lbs
cyl 5 88lbs
cyl 6 90lbs

There the answer , YES it works.



And his final update:

____________________________________________________________________


About 2700 miles, the first 2 oil changes as documented, pulled compression the other day, same as before 120ish. oil is clean, no smoke, no oil burning whatsoever. the plugs i put in right after experamint look perfect. (before i was changing plugs every 500 to 1000 miles.)

Starts fine, runs perfect, not much else to say. worked like a charm.

Absoulutly no adverse affects, and all positive.




Like I said, I'm only reporting............

Don

Could be stress. I've known a few people that smoke when the pressure is on.


ooops sorry, your talking about a motor.....

Thanks for that post Don. Who would have thought or guessed.

Could be the valve guides if just smokin at start up and under load ,not at idle ,could be the rings to ,but they usually smoke all the time ,even worse when hot.

Originally Posted by Itoldyouso

Anything that is supposed to keep oil out of the combustion chamber could be suspect.......rings, valve guides or seals, etc.

There was just a thread on another forum where a guy swears he stopped an old car from smoking by putting Bon Ami cleanser down the carb and it stopped burning oil! He said he put a small amount of cleanser into some gas and slowly poured the solution down the carb as the engine ran, and the cleanser "honed" the cylinder walls and rings enough that they seated.

I am not recommending it, but if it is a high milage car that you just want to get some more time out of.....................

BTW, he suggested changing the oil immediately after so that any cleanser that gets past your rings into the oil wouldn't hurt the bearings, etc. I don't know if it works, I'm just reporting.

Don

this is a old hot rod trick it i have been told it works this was done with chrome top rings to get them to hook up .never have done it i do not use chrome rings.moly like a wall that not to coarse of a hone if the walls did get glazed i can not see why it would not work just do not tell any one that you did it

Bon Ami does work and has been used as far back as I can remember

It was almost standard practice on early farm tractors with diesel engines
Of course this assumes that you have a good wall and rings and just need to seat the rings

Put it in a salt/pepper shaker so you can tap a llittle at a time into the intake air stream---varies as to how much or for how long----

Bon Ami polishes surfaces, its not abrasive and it probably wouldn't hurt the bearings if it did get there