"brett" <account@cygen.com> wrote
> So how long do you usually let your car warm-up during the
various
> seasons?

I live out west in a much milder climate now. Lows in winter
during the day are, at the very worst, around 25 F. And
that's rare. Also, I have a garage. So these days I never
purposely let my Civic sit and warm up upon leaving my
house.

When I go into the mountains to ski, and the car is exposed
to the elements and extreme cold (teens or worse, degrees
F), sometimes I'll give it a minute or so, tops. I don't
know if that's really necessary. (If there's a sheet of ice
built up on my car, that's different, but that's of course a
special situation and not really your main concern, I
think.)

> I guess the conclusion is that it is much better to allow
the engine to
> idle down.

No, I don't think that's necessary at all. The engine
control system senses several parameters (air temp, coolant
temp, etc.) and deals with the car being cool. The engine is
tough enough to take it, IMO. I don't think one will squeeze
more life out of one's car by letting it sit a few minutes,
idling in the driveway, before leaving. Engine oils are
better than they were a few decades ago, as well. (Certainly
synthetic is a vast improvement! I don't use synthetic, but
I would if my car were new or just had its oil lube system
thoroughly cleaned. Not that anyone bothers with the
latter.)

At most, by warming up the car first, I figure one's muffler
might last longer. They rust prematurely when one goes on
only short trips, as you probably know, not allowing
sufficient heating to evaporate away accumulated
condensation in the exhaust system.

> This way, you elimate all valve lash

One is more likely to eliminate all tapping, perhaps. But
again, I don't think a little tapping is going to affect the
valves' life by much at all. I base this on reading about it
on the web. People generally say get it in spec, and better
to tap a little than not at all.

Off the top of my head, I don't know whether eliminating
/all/ the valve stem-rocker arm clearance at normal engine
operating temperatures is desirable or by design.

> and probably a few
> other things you weren't aware of. Do you agree?

No. The engine control system (and thermostat) senses yada
yada (see above) and adjusts fuel flow, coolant flow, and
RPM etc. so as to achieve ideal conditions in a reasonable
amount of time.

Also, I think the engine valve design is plenty tough enough
to deal with a bit of tapping, as long as the lash is still
in spec. (Else the spec for the lash would be more
exacting.)

Keep checking back. Many of the regulars are busy during the
day and do not get to the group until later.