4K High oil temps and cooler question

[George Selby]

At 10:42 PM 9/16/2009, you wrote:
>Hi all,
>my '87 4k oil gets pretty hot on the highway, usually hitting 130C
>(266F) going 70-75 within several minutes of driving, sometimes more
>if the weather is hot. Once getting off the highway, it drops within
>minutes down to the 90s. In town driving I have not seen more then a
>100c on a hot day.

Nothing wrong with that at all.  In fact, you've just discovered why 
city driving is worse for a engine than highway driving.  With city 
driving, the oil never reaches a temp over 100C, and therefore never 
boils off the water in the oil.  This eventually causes the buildup 
of sludge and other nasties in the oil.  You are actually doing your 
oil and engine a favor by running it at highway speeds and allowing 
the oil to reach it's proper temp.

George Selby