My first impression based on your description would be head gasket. I
don't think a burnt valve would cause a great deal of smoke and it would
be a more bluish color. Normally white smoke would indicate coolant.
However, my first MGB was a 65 and on two occasions, it cranked out a
serious layer of white smoke that would have killed every mosquito
within a hundred yards. That happened when the top cover of the PCV
valve fell off but in both cases, I was able to locate it and reattach
it, fixing the smoking problem. Bizarre but true.
From: firstname.lastname@example.org [mailto:email@example.com] On
Behalf Of R. Martin Rogovein
Sent: Wednesday, July 06, 2005 4:07 PM
Subject: big white cloud
I was driving the B today, noticed it was running a little rough, esp.
nothing really out of the ordinary, I thought maybe I got a tank of bad
Then, while waiting at a light the revs started to drop (it usually
smoothly around 900) and it started to stutter.
I gave it some gas to keep it alive, and was rewarded with a white
smokescreen that would have done James Bond proud.
>From then on it kept running rough, smoking especially while
and seemed to be way down on power as well, and would ping if i tried to
give it gas too quickly in any gear.
Oil pressure was normal and stable (45 idle, 70 at speed), temp stayed
Engine has burnt oil since I got it (a quart every few tanks of gas -
probably rings), but I always am careful to keep it topped off (checked
today before I headed out and it was fine).
My guess, without opening anything up to see, is a burnt valve.
Do the symptoms fit, or do you pros have a better idea?