Anybody got any ideas?

[Anonymous]

The 200 in my Mav has an oil consumption problem. The motor has been completely rebuilt from top to bottom. The guy who had it before me drove it after the rebuild for a while but noticed that the engine was consuming oil and the plugs would become fouled after about a week of driving. He replaced all the rings a second time but found that the oil consumption problem persisted. I thought that maybe the problem was valve seals so I just pulled the valve cover and inspected everything. It all looks great, so I'm stumped. Anybody got any ideas?

Here is a summary of the problems:
Oil consumption (about half a litre to a litre a week), plugs become fouled after about a week of driving daily, no noticeable smoke coming out of the exhaust.

Thanks,

Saul

 

[addo]

Have you tested the compression?

I suspect rings upside down.

 

[CobraSix]

Does it lose the same amount of oil if you drive it versus if you let it sit?

Slade

 

[Anonymous]

I don't think it loses any oil when it sits. Only when it is running.

 

[MustangSix]

It may be a ring seating problem. How's your dry compression? Have you taken any readings?

One OLD trick that may work, if it is a ring seating condition, is to remove the spark plug and put a pinch of BonAmi cleaning abrasive into the cylinder. JUST A PINCH. It's a fairly mild abrasive that will quickly be burned off and ejected out the exhaust, but may give you just enough grit to seat the rings.

I'd take a look at the valve seals again as well. It's possible that you could have gotten the wrong seals. The stems are only 5/16", but 11/32" seals look exactly the same. They will fit, look ok, yet allow excessive oil to get down the stem.

 

[Anonymous]

Here is a little more info that might help. I pulled all the plugs, they all have a slight film of oil on them, except the #3 plug which had oil literally dripping off.

Thanks,
Saul

 

[Lazy JW]

Yes, the BonAmi trick does work, it isn't really any thing to be afraid of either. It was actually recommended by Caterpillar as a way to break in their engines. I have an official Caterpillar engine manual that lists their "Break-in" powder (BonAmi) with a Caterpillar part number. They recommend using a tea spoon to feed the powder in through the intake (after the air cleaner) while the engine is running. A couple of teaspoons full should do it. Don't get too crazy with it though.
Joe