[Suimasen]

Hey guys! I've got a bit of a situation. I had a head gasket blow after owning my Trooper for 800 miles. I did a righteous repair (had the head pressure-checked and planed, used a good gasket, torqued correctly), even found the culprit - the PO didn't use the dowel pins when he rebuilt it. Now I find that I am using a lot of oil two quarts or more in a weeks time!! About 100 miles. The oil was fouling out the #4 spark plug but has since stopped doing that. Today I noticed the white oil smoke cloud when I was going down a hill and letting the engine do the braking down the hill. I never see it burn oil under acceleration. I had been told that it produces a little puff when I shift, but hadn't seen any oil smoke until today. I'm thinking that I will need to do rings. Any thoghts on what I might have going on?

 

[psguardian]

Was the bottom end recently rebuilt?

Engine braking leaves the cyls under higher then normal vacuum during the intake stroke, the only other place to draw 'air' from is the crank case. If the ring gaps are too big, not offset as described in the shop manual, or warn out/didn't seat at break-in, they will not keep oil out of the cyls as they are designed to do.

Or other causes; cracked block, cracked piston, bad valve guides & seats, warped block/head surfaces, cyls now cone shaped & wider at bottom then top allowing oil to pass good rings.

~psguardian

 

[mallen]

Hey guys! I've got a bit of a situation. I had a head gasket blow after owning my Trooper for 800 miles. I did a righteous repair (had the head pressure-checked and planed, used a good gasket, torqued correctly), even found the culprit - the PO didn't use the dowel pins when he rebuilt it. Now I find that I am using a lot of oil two quarts or more in a weeks time!! About 100 miles. The oil was fouling out the #4 spark plug but has since stopped doing that. Today I noticed the white oil smoke cloud when I was going down a hill and letting the engine do the braking down the hill. I never see it burn oil under acceleration. I had been told that it produces a little puff when I shift, but hadn't seen any oil smoke until today. I'm thinking that I will need to do rings. Any thoghts on what I might have going on?

Isnt white smoke usually coolant and grey/blue smoke oil?

 

[BrydonJ]

White smoke is caused by water and or antifreeze entering the cylinder, and the engine trying to burn it with the fuel. The white smoke is steam. There are special gaskets (head gaskets are the primary gaskets) that keep the antifreeze from entering the cylinder area. The cylinder is where the fuel and air mixture are being compressed and burned (like psguardian mentioned about the pressure under engine braking).
Any amount of antifreeze that enters this area will produce a white steam that comes out the exhuast.

Check to see if the proper amount of antifreeze is inside the radiator and the overflow bottle. Also check to see if antifreeze has contaminated the engine oil. You can look at the engine oil dipstick, or look at the under side of the engine oil filler cap. If the oil is contaminated with antifreeze, it will have the appearance of a chocolate milkshake.

It seems odd that you're losing that much oil with white colored smoke, no?

 

[Suimasen]

The smoke is definitely blue (oil) smoke. And I was mistaken about the fouling of the #4 spark pug. It fouled again yesterday and when I changed it, it was carboned and full of black goo.

The PO told me that the man he bought it from had put a new motor in it. I believe he had rebuilt it and may not have done a real good job. The pistons are marked with 050 on the top. I don't recall well enough, but I don't think there was any cross-hatching when I inpected it. (This is the same guy that only used one dowel when installing the head). I didn't have an oil consumption problem before the head gasket blew, so that has me stumped. Over the past couple of days it has started showing more signs of burning oil (again usually when the engine is braking but not always).

I think that I am going to have to bite the bullet and plan on a lower end rebuild. (the wife is going to be pissed!)

 

[psguardian]

I don't know if there's enough meat for the block to actually be bored "0.050 over stock. Think he just matched some wrist pin & diameter measurements & called it good.

When u do the take down, make sure a reputable shop gives the block a thorough check & measure BEFORE you buy anything SIZE specific. i.e. pistons, rings, bearings, headgasket.

~psguardian