Blue smoke from exhaust

Hi guys, Just noticed, after having to do an emergency accelerate (my fault) in first gear up to the rev limiter, then changing to second (manual box) that a huge puff of blue smoke, noticable from rear view mirror where I was looking to make sure I was getting out the way, occurred as I changed to second. Is that an indication of valve seals being worn, or piston rings? I used to know the answer in my younger biking days when fuul throttle was a way of life, but I seem to be forgetting more than I once knew, if you know what I mean...

Reply to
Stuart Gray
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From a point at sea, to the circles of your mind, this is Stuart Gray:

Worn oil seals will be most vulnerable to letting oil past when induction vacuum is at its greatest. Closing the throttle valve at max revs as you changed gear would provide such a situation. Accellerating afterwards would provide the conditions to burn off the oil that had been drawn in, hence the blue smoke as you re-applied the throttle.

Another way of checking the valve seals is to roll down a hill, in gear, with the throttle closed. The hill should be steep enough to increase speed as you descend. This will create low induction pressure at tend to draw oil past the seals. Accellerate when you get to the bottom to burn off the oil and look for blue smoke in the mirror.

If it's any comfort, a little oil can make an aweful lot of smoke.

Reply to
Stewart Hargrav

Damn, the only 2 downhills I know locally to accelerate the car on closed throttle both have a blind 90 degree bend at the bottom and both definately need eyes front if accelerating out of them. Must try with wife in passenger seat looking backwards - if I can get her to trust me that much - she usually sits with the passenger brakes on ; )

Stuart.

Reply to
Stuart Gray

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