Engine burning oil after rebuild....have 170 compression

[LavaSurfer]

Like the subject says I recently rebuilt an E motor to swap in my 528e. the engine was out of my 87 325e that I yanked for a motor swap. I checked the block with my inside micro meters top, middle, bottom on the x & y axis....blah blah. And it all checked out good. I have all the measurements written down somewhere since I had never actually "blueprinted" a motor on my own and did it for the fun of it. The engine ran and drove great when pulled....I just wanted to rebuild it for good measure. I also had the head checked and I left new valve seals with the head shop to install in the head. The valve seals looked new when I picked it up. Maybe I got screwed and they didn't install them?

However now I'm a going through oil like candy (about 1 qt per 200 miles), but the engine has power and runs absolutly awesome. It actually suprised me of how much low end torque these e motors have when they are fresh. I pulled the plugs and they all have a equal amount of oil residue on all of them so I don't think I have one cylinder with a bad valve seal or a blown head gasket so an oil return. About the only thing I can think of is I have something wrong in the crankcase breather system allowing oil to get sucked into the intake? I find it hard to believe that I have a bottom end problem with 170 psi across all 6 cylinders! Also if I get on it I get a TON of oil smoke out of the exhaust for about 5 seconds then it clears up like its collecting somewhere in the intake system.

[jlevie]

What was the wear, measured to a ten thousand, of the cylinder bores? Did you have the cylinders cross hatch honed? Were the ring gaps measured and adjusted during the rebuild? Were the valve guides checked for wear? Has the engine been properly smoke tested after the rebuild. Any of those could result in excessive oil use.

[LavaSurfer]

The cylinder bores were all well with in the service limits in the Bentley for size and runout. I also got a ball hone and deglazed the bores before final assembly. All I can say about the head is that the shop I left it at said everything was good. They were recommended by the local euro forums and the guy sounded like he knew what he was doing and knew what the head was off of the minute I set it on his counter.

The cylinder bores where 3.308 with a couple measurements out by .0005 towards the bottom. But in my Bentlet the maximum conicity spec is .0012.

[AndrewBird]

Did you use any kind of assembly lube when you installed the pistons, or did you put them in dry?

[LavaSurfer]

I used Rotella oil during assembly and for break in Bearing lube on bearings.

[Jaxx_]

do you have more smoke on startup than any other time?

[LavaSurfer]

I do sometimes. It doesn't do anything consistantly other than somehow consume it at the same rate pretty much anyway I drive it. The past couple days I get a puff of grey on cold start up. But I do notice when I'm in stop and go traffic that I get a puff of grey after I've been idling and step on the gas to move up.

[LavaSurfer]

Is there some sort of breather filter that I didn't install correctly? I replaced the metal tube that goes from the block to the bottom of the intake with dealer parts since the original one was very rusty.

[LavaSurfer]

A little eye candy. It would really suck if I do have a bottom end problem. I definatly took my time to do it right!

[jlevie]

Smoke test the engine. If you have an air leak into the engine you will get oil burning.

[TobyB]

Maybe I missed it- did you reuse the pistons? New rings? Whose rings?
Didn't align the ring gaps, did you?

Non- synthetic Rotella, right?

(just going through the list of things that could go wrong...)

t

[digger]

sure its not leaking somewhere?

[Nutzy]

check inside throttle body and peek into the manifold to look for lots of oil. Assuming your pcv is connected as per stock.

[LavaSurfer]

I used rings that I purchased from goetze rings that I purchased from autohausaz. I reused the pistons after I put them in my small sonic cleaner and decarboned them. I measured them and there was pretty much zero wear on them also. We have one at work for cleaning small carburetors. All rings were clocked per the instructions that came with the rings with plenty of oil before dropping them in the holes. And it was plain old Dino rotella that I got from the truck stop down the road.

[LavaSurfer]

sure its not leaking somewhere?

I get one drip smaller than a dime if she sits for over a week in the driveway that I have yet to investigate. Nothing alarming by any means.