> I'm almost embarrassed to admit this, but I'm not exactly sure what
> pinging sounds like.
No problem. Perhaps I should use the formal term and start calling
it pre-ignition, because "knocking" and "pinging" can both be kind of
confusing.
Once you figure it out, though, you'll want to avoid
it like the plague. It's pretty much the Sound Of Engine Death if
you don't get off the throttle, and both the owner's manual and FSM
back me up here.
> I have noticed that recently, in the winter, under
> times of hard accelleration, the engine will do something that I'm
> interpreting as pinging.
Well, that probably makes 3 of us that may be seeing what I'll
call the Winter Gas Blues. ;)
> I'm not
> sure, but I think it is accompanied by a loss of power. It sounds very
> much as if it were in fifth gear and trying to go up a steep hill... Its
> not so much what I'd call a "ping", maybe more of a "knock".
>
> Is that pinging?
I'd lay bets that it is. It's a foul and disgusting sound that
makes your butthole pucker.
It's caused by pre-ignition, when the air/fuel charge ignites
earlier in the compression-to-power stroke transition than it's
supposed to. Pre-ignition may be induced by a number of factors,
like bad gas (lower than needed octane rating), lugging the engine
(the 5th gear scenario you describe), excess engine heat, or
combustion chamber deposits (either through increased compression
or hot spots).
Pre-ignition can destroy an engine, so I tend to be a little
paranoid. The power falls because the engine is literally fighting
itself. A little knocking at low RPM is normal, but at high RPM
it can be deadly.
> If so, I'm experiencing the same thing with 87 octane here. This didn't
> happen last winter though. I haven't tried higher octane yet. I just figured
> I'd gotten a bad tank of gas.
Sounds exactly like what I'm seeing. Try playing with gas grades
and tell us what happens. I plan on going right back to 87 when
spring hits, will post results.
Heck, I may search for a brand of 87 that works well now.
Ron
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