Valve seal/oil consumption questions...

[okartguy]

Guys-

Here are my symptoms: Blue oil smoke when accelerating from a stop through first and second gears, particularly when the car has idled for a minute or so. No discernable smoke once underway, but it reappears in the mirror when decelerating and then reaccelerating, especially at highway speeds. The car is using a quart of oil every 4-500 miles, and there's a fair amount of "soot" on the back of the car.

The motor appears to have been rebuilt fairly recently, as it's very clean top and bottom, and removing the valve cover reveals an extremely clean valvetrain. Also, the car runs like a watch, has good power and starts immediately hot or cold. However, the car was stored unused for at least two years prior to my ownership, so I suspect the valve seals dried out and are to blame for the oil consumption and soot.

Given that the car runs so well and it appears that the motor is healthy, what's the best way to remedy this? Forgive my ignorance, but can the seals be replaced with the head on the car, or does it need to come off? What are my options? I'd like to fix it right, as the smoke and the burnt oil smell are becoming tiresome. TIA-

[Beaner7102]

I cant answer the cause, but I have a motor that is doing the same thing, it too was in storage for several years. But I do know its best to do the valve guides with the head off. Beaner7102

[ray_]

What oil are u running? I would suggest Castrol 20/50 at least for spring thru fall. Lighter oil may be... too light!

Good luck!

Ray

[Mike Self]

rings...smoke under deceleration = bad stem seals/valve guides. If the engine has sat for a loooong time, the rings may be sticking in their lands, but they should loosen up after a few hundred miles unless they're rusted or broken.

Valve stem seals can be replaced without removing the cyl head (see archives) but not the guides. Also, to use the late style stem seals (superior to the original ones used on '02s) you must also press out the old guides and fit the later style guides. That of course requires head removal. If you're not sure whether the guides were replaced in the "recent engine rebuild" you mentioned, I'd replace the guides. However, be aware that when you tighten up the valves/guides, it'll cause weak rings to leak even more--I found this out when I did a valve job at 157k, only to have the rings start to pump oil...

First thing I'd try is using 20w-50 oil; that'll cut consumption over 10w-30 or even straight 30 weight.

cheers

mike

[c.d.iesel]

COMPRESSION TEST and

CYLINDER LEAK TEST : THIS WILL REVEAL

if the ring gaps are not staggered and permitting oil to

come up from the bottom into the combustion

chamber - smoking on accelaration is not good after

a 'rebuild" - or worse, a broken ring, or .....

how about the 'rebuilder' taking a look at his product ?

cylinder leak test will also show if the head gasket is leaking the oil

where it doesn't belong

then - you could have botched/butchered valve guides, loose in the head,

or sloppy fit with the guide i.d. and the valve stem - and loose or valve seals not firmly seated on to the guide -

you have a problem...................

1 quart in 1,000 is permissible oil cunsumption - on a 'worn' motor,

not a rebuilt one.

[Grover]

My car was doing exactly the same thing (with only about 20,000 miles on a full rebuild) and I just took it in for a leak-down test yesterday. The results showed that the rings were perfect with virtually zero leakage, but there were leaks in the valve stem seals. I was quoted $800-900 for this repair but this definitely entailed removing the head and having it remachined amongst other things. If this repair can be done without removing the head I'm certainly curious to explore that more.

[c.d.iesel]

.....it can not - removal of the head is a must.