Re: [DML] Transmission and Oil question

[Martin Gutkowski <webmaster@xxxx>]

Tom, please qualify this statement. Letting ANY engine idle for a time is a very GOOD
thing as it gives the oil a chance to circulate around the engine. In all my cars I make
sure to take the first 2 minutes on half throttle

See this - written by a very qualified aussie scientist, and fanatical 4WDer.

http://www.abc.net.au/science/k2/trek/4wd/oil1.htm
http://www.abc.net.au/science/k2/trek/4wd/oil2.htm
http://www.abc.net.au/science/k2/trek/4wd/oil3.htm

It's a good read even if you're not particularly interested in this thread. Quote:

I was delighted by some research done by Castrol with Rolls Royce, at the Nuclear
Research Institute at Harwell in the UK. They cut through some myths and got some hard
facts. Over several years, they "X-rayed" engines while they were running. They used
neutron beams instead of X-rays - they could, for the first time, actually "see" the oil
flowing through the engine.

The engineers were amazed by the results. Once the engine had started, it took
much longer than everybody had thought for oil to reach all the parts of the valve train.
In some modern engines, it took several minutes (not seconds) for the oil to reach all
parts of the valve train and complete the oil circuit - and this was at room
temperature! The situation got worse at lower temperatures. It took twice as long at 0oC,
and 4 times longer at -10oC. Some engines have balance shafts that run at twice the
crankshaft speed. The bearings on the balance shaft can suffer a lot of damage by running
dry for a few minutes. A cold start can be a dry start.

Martin
#1458

Tom Niemczewski wrote:

> Speaking of confusion... how many of you let the engine warm up for a moment
> before you drive it? I bet that most people will say that letting the engine
> idle for a moment is a good idea. And the fact is that this is the WORST
> thing you can do!