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-   -   I am totally baffled with a oil burning problem...ugh (https://mustangforums.com/forum/classic-mustangs-tech/580175-i-am-totally-baffled-with-a-oil-burning-problem-ugh.html)

scootchu 01-05-2010 06:43 AM

I am totally baffled with a oil burning problem...ugh
 
Guys humor me on this one please.
I get no oil burning smoke on a cold running engine, but run the engine for about 45 mins and I then get smoke from the passenger side. I get this smoke when I come to a stop and idle or after a rev while idling.

It seems to be worse after driving on the highway annnnnnnndddddd it isn't always predictable.

What is also puzzling is that fact that my oil level really doesn't drop. I have read so many places that people don't see smoke yet lose oil through burning.

I have narrowed it down to one particular cylinder on the pass side and "think" rather than rings it's either worn guides or a leak on the underside of the intake manifold.

My theory is the oil thins when the engine warms up completely and then the high vacuum either pulls the oil in through the leak in the manifold or down through the valve guide creating my smokescreen. The valve stem seals were replaced over the summer, but they were still the crappy umbrella type.

I have also read that burning through the rings is less noticable as smoke because of the higher temps in the crankcase and through the heads produced more smoke.

The heads will be coming off soon anyway, but I wanted to post this for two reasons; one for my own sanity and the other to help anyone else that may have a puzzling problem.

The engine runs like a raped ape otherwise.

kalli 01-05-2010 08:58 AM

maybe ... just maybe, you're replacing the missing oil with petrol ?? vurning oil through piston rings and petrol leaking into oil through piston rings.
I'd try a compressiontest (dry/wet) just for a quick check

2+2GT 01-05-2010 09:00 AM

Do a wet/dry compression test. Then you'll know if the ring are OK.

scootchu 01-05-2010 10:04 AM

Sorry, I forgot to mention that I have done a dry compression test and I was around 130 on all cylinders. Haven't done a wet test.

Here is another strange one. It also can be made to smoke if the car is on an incline facing down.

The oil always stays nice and clean and doesn't smell like gas.

I am going out to look at the seals. I suppose I should look at the play in the intake valve stem too.

7 UP Mustang 01-05-2010 10:33 AM

Sounds to me that the drain down openings for the oil maybe blocked or stopped up. The oil may be accumulating, and not draining back down to the oil pan. Good luck.
LARRY

MonsterBilly 01-05-2010 10:34 AM

I am having a similar problem except that i lose oil quick. I just had it rebuilt and i go through about a quart of oil in a tank of gas. it is really annoying and i think i should take it back to the guys that rebuilt it and make them figure it out.
i have good compression as well. i think that it is leaking through the valve seals.

67mustang302 01-05-2010 12:53 PM

What color smoke? White = coolant, bluish = oil, black = fuel.

And are you sure it's coming out the tail pipe and not dripping onto the exhaust someplace?

scootchu 01-05-2010 02:23 PM


Originally Posted by 67mustang302 (Post 6731754)
What color smoke? White = coolant, bluish = oil, black = fuel.

And are you sure it's coming out the tail pipe and not dripping onto the exhaust someplace?

Who me. LOL
Yep it's light blue, more white-ish blue and I smell like I have been using a weedwacker. I just replaced the seals on the passenger side and while idling I had no visible smoke, but I can't take it for a ride because I am waiting for the cable guy to get here.

I had a more play on the intake valve of the suspected cylinder then the others. I am going to put a set of GT40 heads on soon so if it is worn guides, that problem will go away. I will see if I can get out for a ride later and see if I had a positive affect on the problem.

Gun Jam 01-05-2010 03:16 PM

It doesnt have a PCV valve on it does it?

I had a PCV act up and every time I let off the gas after accelerating hard it would blow a bunch of smoke out the back...replaced the valve no more issues.

-Gun

67mustang302 01-05-2010 04:11 PM

Check all your plugs. Could be an intake gasket, could be rings, could be valve guides/seals.


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