just rebuilt engine, now burning oil just as bad

[night-rider]

so i just finished rebuilding my 7m gte as it was burnign exessive amounts of oil before, machined the block .020 over and used a reman cyliner head complete. at first when i ran it in the garage it seemed fine. now after driving it for a couple hundred kms it is burning just as much oil as it was before, used 10 40 mineral oil for break in did multiple oil changes, no pcv and intake is free of oil, at this point im suspecting rings as the head is a brand new reman with new valve guides and seals. blue smoke is most noticable on decel and when coming to a stop, but can be seen on accel aswell, none on startup, none at idle, has anyone had issues with rings seating or anything like that, all oem bottom end just bored .020 over, some people are telling me to just do more highway driving for break in as it has been all in town driving, i am also considering trying an actual break in oil or thicker oil maybe 10-60 or 20-50, has anyone had anythign like this happen before?

[87hilux7mge]

have you done any load runs on the engine? if you brought it straight to idle and started driving it after you got it running again, you may have galled the rings?

did you thoroughly clean the cylinder walls after you got it back from the shop? i know my shop puts a protective coating on the cylinders to prevent surface rust, and it must be thoroughly washed off before assembling the short block, or the rings will gunk up, shelaque and no seat...

just a couple ideas, hopefully it helps. definitely sounds like a ring seat problem though.

[mirage83]

I've seen it recommended in a couple of different places (and is the method I used to seat the rings in my re-man) find a relatively clear road and in low gear accelerate up to around 4k rpm, hold a moment, and then with the car still in gear back off the gas and let it come down to a creep. Repeat 4-6 times.

If that doesn't at least help a little, then I think you've got a more serious problem than rings not seating properly.

[87hilux7mge]

another method (albeit very similar) is to cruise at 35 mph in third gear, then perform full throttle accelerations to 65, w/o shifting. deceleration under gearing isnt necessary for this method. perform this 4-5 times and then drive the car as you normally will for the span of its life.

if your rings take longer that 2 hours of driving to seat, then you have a serious problem, and they are probably shellacked and the cylinders will be glazed.

[night-rider]

thanks for the input guys, i will try those methods. as for the coating on the cylinder walls there was nothing to obvious there other than a light coat of oil from what i could tell, regardless i did clean the clyinders and deck before assembly.

[night-rider]

well i tried out those couple methods and it did not seem to help, its odd though sometimes after going to 4k and then decelerating it would blow alot of smoke and other times none at all, ive also noticed that after driving on the highway it doesnt burn any at all for a few minutes after. the car still has power it doesnt feel sluggish at all, and even just driving around town it doesnt always blow smoke, i find that odd.

[87hilux7mge]

the other possibility is bad turbo seals. even if they werent doing it before, something could have happened during the rebuild.

hows your power and running? is it bogging, chugging, running like crap etc?

check your turbo and IC and piping for oil.