m50 head rebuild? ..HELP!!

[dnick]

Alright so im sorting out problems with my swap, Ive done a compression test and the numbers are great (see my build thread).. but the bitch is smoking and i saw oil on the plug.. SO people said to replace the valve cover gasket and one of my friends said to also replace the valve stem seals. Im going to go ahead and do this, but are there any tricks or tips that i should know about? What brands to get or stay away from? Im trying to learn as much as possible before tackling this!
Engine is a m50tu.

[DesertBMW]

remove head, clean the surface and check for cracks around water ports, very common issue.

[dnick]

I'll look for that..

[jrdeamicis]

Is it smoking out the tailpipe or in the engine bay?

[dnick]

tailpipe.

[jrdeamicis]

When is it smoking? idle? All the time? Only under heavy throttle? What color? What temps?! SO MANY QUESTIONS?!?!

[dnick]

When is it smoking? idle? All the time? Only under heavy throttle? What color? What temps?! SO MANY QUESTIONS?!?!

pretty much all the time, and.. hm well lol its burning oil color lol,
its still not tagged yet, im still finishing up building the car.. its just open header right now, no o2 sensor currently.. i havent run it longer than like 10 minutes yet. It does smoke more under heavy throttle. Im pretty sure the rings are fine because the compression test was good.

[TimKninja]

No 02 will cause a rich condition which causes white smoke out of the exhaust.

What does it smell like? You can smell it burning oil if it is.

[dnick]

No 02 will cause a rich condition which causes white smoke out of the exhaust.

What does it smell like? You can smell it burning oil if it is.

yeah it smells like burning oil

[etxxz]

valve stem seals are easily doable with the head on FYI. You can either use the trick of feeding a rope in through the spark plug to keep the valves in place or the same but to feed pressurized air. The purpose is to not drop a valve while you remove and tap back on the valve seals.

Just do one cylinder at a time. you can make your own valve spring retainer removal/install tool with a steel C bracket IIRC i found the idea on bimmerforums. pm me if you need info help on removing the cam properly torque specs etc.

[dnick]

valve stem seals are easily doable with the head on FYI. You can either use the trick of feeding a rope in through the spark plug to keep the valves in place or the same but to feed pressurized air. The purpose is to not drop a valve while you remove and tap back on the valve seals.

Just do one cylinder at a time. you can make your own valve spring retainer removal/install tool with a steel C bracket IIRC i found the idea on bimmerforums. pm me if you need info help on removing the cam properly torque specs etc.

got a pm lol.

[hwy84]

yeah it smells like burning oil

Dumb but possible:

How clean are your exhaust manifolds? If you spilled oil on those bad boys, or if they were sitting in a dirty box with a bunch of other accessories and crap before you stuck them on the motor, it will take a WHILE for everything to burn off... Just handling mine with dirty work gloves as I welded up and filed the exhaust ports (S52 manis on S50) got them oily enough to smoke pretty good for quite a while when I actually ran the car for the few few times. And with the engine bay open, you really notice it.

Might seem lame, but before I started doing valve seals, I'd wanna make sure the stupid stuff is perfect...

[etxxz]

Try doing the napkin test i told you about.

If you get wet oil residue on your hand/napkin/towel you're probably past the realm of valve stem seals and looking at bad oil scraper rings, or scored cylinder walls in the rear bank (cyls 4-5-6). Bad rings usually product blue(ish) smoke too.

Just smoking exhaust could be valve stem seals. That with a valve cover gasket is cheap enough, just time intensive... like a whole day's worth of work.

Here's a tip to help you nail down whether its rings or valve seals.

Redo the compression test (must have WOT) - gives you X numbers.
Add little over a tbsp of oil to that cyl and redo the compression test. If numbers go up, you have a valve stem seal problem, but if numbers stay about the same then its likely the rings not sealing well and even more likely scored walls to go along.

let usknow mang and good luck.

[dnick]

Try doing the napkin test i told you about.

If you get wet oil residue on your hand/napkin/towel you're probably past the realm of valve stem seals and looking at bad oil scraper rings, or scored cylinder walls in the rear bank (cyls 4-5-6). Bad rings usually product blue(ish) smoke too.

Just smoking exhaust could be valve stem seals. That with a valve cover gasket is cheap enough, just time intensive... like a whole day's worth of work.

Here's a tip to help you nail down whether its rings or valve seals.

Redo the compression test (must have WOT) - gives you X numbers.
Add little over a tbsp of oil to that cyl and redo the compression test. If numbers go up, you have a valve stem seal problem, but if numbers stay about the same then its likely the rings not sealing well and even more likely scored walls to go along.

let usknow mang and good luck.

there is oil blowing out of the exhaust, and i can see it on the ground by the header (exhaust isnt complete yet) .. well, im fucked