cold weather smoke

[friendsam]

I have a 1992 Mazda B-2200, 2bbl carb. During cool weather(below 50'F), my truck puts out a huge dense cloud of blue-grey smoke when started cold, it only lasts about a minute,,,as if it has bad valve seals,,but at temps above 50'F appx. there is no smoke at all,,it never smokes just a little, and never in warm weather. My (co-worker experts???) have told me it is ,,sludge,, egr valve,, catylatic converter,, 02 sensor,,etc.. Has anyone seen this problem?

[DaddyG]

I had the same problem until I cleaned my egr valve. It took care of the smoke. Be careful not to tear the seal DarkOrange

[Livin Low]

you have 1 of three things burnt valve seals,a blown head gasket or you're rings have gone bye bye.Peace!

[MazdaB1300]

It's probably not your rings or else it would always smoke. It's your stem seals. That's what always seems to fix the problem. Plus, the head gasket would be white smoke, not grey or blue. Blue is oil.

[asagan]

My truck, 1990 - B2200
I had the same problem a few years ago. It started with a little smoke and progressed to massive smoke on startup. It would not happen if my truck was parked facing downhill, but would happen on flat or facing uphill. It went on for two or three years until I figured out what the problem was. I took it to a couple mazda dealers, and they didn't fix it. I also took it to a mechanic who said he had another mazda with the same problem, but they didn't know what was causing it. They did a whole valve job and replaced the piston rings which solved the problem. But he says they are not sure what the problem was.

So here was my problem. One of the piston rings was bad. When cold it was not sitting properly, and once it was warmed up it would sit properly. That is why it only happened when it was cold. And it was the piston near the firewall, which is why it would not do it if I was parked facing downhill. The oil would collect near the front of the oilpan so there was less oil for the back piston on startup. This was actually the case early on but over the couple years it eventually didn't matter how I parked.
To fix it I pulled the pistons and put in new rings. This was about 100,000 kms ago and it has been running fine since. A drastic fix but I tried everything else and nothing would work. After much research it was apparent that this was indeed the problem and a common one for the B2200 trucks. And by the way, the rings looked perfectly fine when I pulled them.