Brat's engine and blowby problems...

[Mr. Carb]

My Brat, aparently has suddenly developed so much blowby in the oil that it now runs the oil pan down by 3 quarts in the course of 400 miles.... This, as far as I know, is not normal behavor, as it used to never lose any oil, at all until it was oil change time. But 2 months back, it started burning oil badily, it's not leaking oil anyware, no puddles under the car, but it's losing a quart of oil per tank of gas now. I'm asuming the rings in the moter have expired and gone to the other side at this point. Time for an engine rebuild!

[Ross]

Generally, rings etc wont cause oil burning suddenly, so maybe you should check your PCV system first.

It could have broken a ring though.

[Mr. Carb]

Generally, rings etc wont cause oil burning suddenly, so maybe you should check your PCV system first.

It could have broken a ring though.

 

I'm thinking it's probably a broken ring, or it just suddenly progressed. It had a little bit of blowby previously. It's a really old moter to my understanding so I think the rings just hit that point in life where they completly die.

 

I think I'll check the pcv valve though... when it's daylight out.

[NorthWet]

Blowby doesn't cause oil consumption, unless the PCV system allows oil to be pushed into the intake tract. Blowby is compression leakage (tending to push oil away from combustion chamber) past the compression rings, or exhaust gas leakage out the valve guides. Damaged oil control rings would allow more oil to get past the compression rings into the combustion chamber to be burned.

 

So, are you getting oil forced into the intake tract (most notable in the air cleaner box) and is your compression readings down? Or is your compression still good and your sparkplugs showing oil fouling?

[Mr. Carb]

It beltches blue smoke when I get heavy on the throttle for instance, getting on the freeway. No oil is actually around the air filter... or in the intake pipe. So it's getting in around the valves or past the piston rings.

 

Blowby doesn't cause oil consumption, unless the PCV system allows oil to be pushed into the intake tract. Blowby is compression leakage (tending to push oil away from combustion chamber) past the compression rings, or exhaust gas leakage out the valve guides. Damaged oil control rings would allow more oil to get past the compression rings into the combustion chamber to be burned.

 

So, are you getting oil forced into the intake tract (most notable in the air cleaner box) and is your compression readings down? Or is your compression still good and your sparkplugs showing oil fouling?

[MorganM]

That's some seriouse blow by man. Mine has it pretty bad but I dont use nearly that much oil. I'd say you have a broken ring or a valve guide went bad; something broke

 

Run a compression test.

[ccrinc]

A leakdown test is far more reliable as an indicator of failed rings.

Do a leakdown test first, then if indicated, a compression test.

 

 

Emily

http://www.ccrengines.com

[Mr. Carb]

I suspect it's a valve. Likily the one on the drivers side for piston #4. Last time I pulled up the intake manofold, there was a bunch of black down the one side of the head's intake port, indicating a valve wasn't sealing all the way, or something was malfunctioning. The moter is still very peppy for an ea81, it easily gets the car up to 70mph on the freeway. It's just losing oil doing so. I'm going to tear into it after I have another car to drive to work and back.