engine and drivetrain Blue smoke, newly rebuilt engine...

[Guest Anonymous]

URL: http://www.geocities.com/karlkarlb/BMW.html

I have a little blue smoke problem on my JUST rebuilt engine. It has a total of about 10-15 miles on the rebuild and another 30 minutes of idle time.

It smokes just a tiny bit at idle, but when I punch down on the throttle linkage I get a good puff of blue smoke. When driving down the road, there is no smoke.

There is black soot on the inside of the exhaust tip and the plugs are pretty black.

The cold start is not leaking any gas and the vacuum hose from the brake booster is dry inside.

The car was running pretty rich before and may have thinned the oil a bit, could that lead to a little smoking?

It has new rings, the cylinders were honed, new valve seals, 3 angle grind, valve guides were determined to be OK by the shop.

Any other ideas?

[Guest Anonymous]

If you used chrome rings (read 'hard') then the rings have not seated yet, which is probably your issue. It could also be your head which is unlikely, but possible if one or more of your valve stem seals is leaky.

I would drive it normally for a while and see if it goes away. It can take quite a while for some rings to seat fully.

Good Luck,

Mike (#87)

[Guest Anonymous]

URL: http://www.geocities.com/karlkarlb/BMW.html

Don't know if they are considered HARD or not. The valve seals are new, and the machine shop used the updated seals.

[Guest Anonymous]

Yes, Deves are HARD and may take a while to seat. I think that is your issue.

Mike (#87)

[Guest Anonymous]

Have you honed the bores with a ball hone stones or straight stones??

Honing with stright stones on a tired engine block may cause this: the stones dont reach all the surface since it is not perfectly straight. Did you get a cross hatch patern all the way down the bore?

Did you take some measurements of the bore??

Pat Allen

[Guest Anonymous]

what oil are you using for the initial 300 miles? you should be using a crappy oil, like quaker state 10/30- or similar"thin" oil. it is sacrificial- it needs to be junky so that your rings can seat properly and quickly. . sounds like that has not happened yet. if all your build specs were in order, make sure you get a non rich gas mix going - the overly rich mixture will lead to gas that can wash away the lubricant in the cylinders and really screw up your work. and use some 10/30 regular oil for first 3-500 miles. there are specific rpm and timing sequences to follow: this is a subject of debate- the archives should have pages of discussion. I followed my builder's orders to the last detail and had 2 successful break-ins on 2 M10s. The BMW handbook, for your year car/engine has a useful break -in guide if you do not know a builder who will share break-in outline. Good luck- keep varying rpms constantly and do not exceed rpm levels on a guide that you decide to trust. you are not out of the woods for at least 1k miles, more like 2k before you can really take the rpms up high and stay at sustained rpm levels for a long run. I follow avery conservative break-in schedule, but it is protection of investment and setting up for a longer engine life.

[Guest Anonymous]

URL: http://www.geocities.com/karlkarlb/BMW.html

got a great crossed-hatched pattern. The bores were to spec.

[Guest Anonymous]

URL: http://www.bmw2002faq.com

(nt)

[Guest Anonymous]

(nt)