Worn rings will pump oil through the forward breather tube on the valve cover and slowly but surely collect in the throttlebody. If ya remove the air tube and oil dribbles out the T-body...rings are allowing blowby to push higher amounts of oil up through the venting system. Im thinking its topend related...not so much a worn valve stem seal. Im thinking you had a seal come off the stem or is so badly damaged that the higher RPMs are lifting and allowing the oil in. Pull your plugs and look for one thats uglier than rest...should always be done first when diagnosing...plugs tell all. If ya see one that is funked up, then pop the valve cover and hunker down to peer through the springs and see if the seals are seated squarly and that none are chewed up. No smoke at lower RPMs...Im thinking that your bottom end is ok. <img src="/forums/images/graemlins/kewl.gif" alt="" />
~Darin <img src="/forums/images/graemlins/baby.gif" alt="" />

This may sound dumb but, how the brake fluid level? I've seen brake boosters suck the fluid out of the master cylinder. The engine burns the fluid and you get lots of smoke. Just something else to check.

>>>*The key here is the "Brown" part. This is the sign of an engine that has been using some oil for quite awhile. The exhaust system soots up, and the force of the exhaust at higher RPM blows loose some of the carbon, which will be brown with some blue, oil color, mixed in..
*Yep, rings.....*EB

Thanks everyone for the help. The truck had been sitting quite a bit the last few years with the PO. I've just now been able to get it back on the road. The carbon buildup in the exhaust makes sense now. Guess I'll try to take it easy on her and stretch her life out as long as possible. This is my bargain wheeler/project, so I can't put too much more money (or time) into it.

Anyone have any suggestions as to what oil to run and/or what additives to run......to try to minimize the oil burning? I used to have good luck with the Engine Restore stuff in my old Nissan. Now, they have high mileage oil too.

Ok, I've got another question.

Is there a way I can tell if its the valves vs. the rings? I plan to adjust the valves in the near future and check for seal problems etc., but I'm taking her on the maiden voyage this weekend and it will be the perfect opportunity to look and listen for clues.

Also, it is burning about a quart of oil every 200 miles <img src="/forums/images/graemlins/frown.gif" alt="" />

Do..or get a leakdown test done. What this involves is filling the cylinders with compressed air one at a time, theres a set of gauges you connect to watch the psi, depending on how fast pressure is lost determines the severity of the problem. The cool part is its easy to figure out where the air is going. If you hear it out your tailpipe then its the exhuast valve, coming out of your throttle body then intake valve....anywhere else especially the oil filling hole in the cover means the rings are long gone. A quart every 200 miles? Wow, when I lost the rings in #4 in the Gen1 motor (30# PSI) I was loosing a quart about every 1,000 miles. And as I previously mentioned, I found all that nice oil in my throttle body and intake due to the venting system...carried by the blow by. Any signs of external leakage to go with your smoke?
~Darin <img src="/forums/images/graemlins/baby.gif" alt="" />

No external leakage at all, nice having an old truck I can park on the concrete driveway <img src="/forums/images/graemlins/kewl.gif" alt="" />.

Throttle body was sorta nasty when I opened it to clean it, but it wasn't horrible. I've only put around 700+ miles on it since I got it and began rebuilding the truck in August, so some of the stuff may not have had time to get really funky again. PCV still has a clean film of oil on it, but nothing gunky. I'll pop the TB off again tomorrow and take a peak. Guess I'll have to look into a leak down test, I thought that was when you put some oil on top the piston for compression check.

Truck only has 144,000 miles on it and it runs beautifully, so its a shame its burning oil. I think we have a love-hate relationship.

yea you can do it that way too ,if you get low commpression ,squirt some oil into the cly,then do it again ,if the reading improve its the rings ,if they stay close to the same its the valves

I don't have the numbers here in front of me, but when I did the "dry" compression test, it was within or slightly higher than spec....all cylinders were within about 7-8 psi of each other. When I did the "wet" test, I believe it bumped each cylinder up a little but not more than about 10 psi, again rather consistent between all cylinders.

Would this slight of an increase in pressure indicate rings so severally worn that it would burn like this? The valves make practically NO noise for a Toyota, maybe that's a sign.

*Just for comparison purposes for you Axle, when the Gen1 gave up its #4 rings it did it in two steps. First occurance- compression check dry resulted in 60 PSI, wet with oil- 100 PSI.
Second event took place about 10 days later. Results for compression check: dry- 30 PSI and wet- 60PSI.
Keep in mind that when I say "gave up the rings" they literally shattered and took out part of the ring lands on their way up into the combustion chamber.


If your compression readings were that close to spec and had less than 8#s difference between cylinders than I dont think that rings are your problem. Backing that thought up- if a wet compression test only raised the numbers 10 PSI or so...seems to me the problem lies elsewhere. Did you do the test with engine hot..or at least warm? This one has me boogered good...hope we can get to the bottom of the cause. Maybe Im totally wrong in my assesment- has happened plenty times before. And afterall..we DO HAVE them madcows here. LOL
~Darin <img src="/forums/images/graemlins/baby.gif" alt="" />