[OFB Cafe] Engine overheating

[Rick Bowers]

At Tuesday 7/15/2008 07:47, you wrote:
>Rick --
>
>I had those symptoms once. The problem was that one of the cylinders had
>much lower compression. At idle that cylinder wasn't doing any effective
>work and was a load on the others.  Other symptoms were a rough idle and
>high (unburned) hydrocarbons on an emissions test. I got rid of the car.
>(I had bought it used. The prior owner must have had a low oil or
>overheating event.)
>
>Peter Hollings

I've checked the cylinder compression. there are two that are low, 
but not REAL low.
I have a smooth idle, and it passed MA emissions testing in march.

Thanks for the input, though.

Now, if I could get my da*n motorcycle running ...

~Rick


>Rick Bowers wrote:
> > Hi all,
> >
> > Here is a "technical" question for the Cafe, even though it's not the
> > Truck Stop Cafe. ;-)
> >
> > For the past several months, more frequently now that the weather is
> > hot, the engine in my Durango has been overheating.
> > It actually started last year, then stopped in the fall as the
> > temperatures dropped. It hasn't overheated again until the weather
> > recently got hot. Even when stopped at lights for extended periods.
> >
> > Here are the symptoms:
> >
> > - I can drive at highway speeds all day and the temperature stays normal
> > - If I get off the highway, or slow down due to heavy traffic, the
> > temperature soars.
> > - If I get back above about 40 - 50mph, it cools back down.
> >
> > Here is an example. I drive home from Cape Cod, about 90 miles. The
> > engine is running at normal temperature.
> > I get off at my exit and drive about 1.5 miles on 30 mph roads with a
> > few stop lights.
> > When I arrive home, the temperature gauge is pegged in the red, the
> > radiator is bubbling, and the overflow is dumping anti-freeze.
> >
> > When things cool down, I check the radiator levels. It's full.
> > This weekend I flushed everything as best as I could and put in new
> > antifreeze. When I drained it, the initial drainage was almost black
> > and as thick as oil. Ughh. But that was just in the bottom because
> > shortly after it turned liquid and just brown. It did need a change.
> >
> > After the flush and fill -- same problem. It still overheats at slow
> > speeds/stopped.
> >
> > During the flushing, I put the water hose into the return (water pump
> > to radiator) hose and pushed water back through the water
> > pump,  through the block and out the radiator drain.
> > I ran it until the water was clear. I also ran the motor to heat it
> > enough to (I think) open the thermostat first.
> >
> > I don't suspect the thermostat -- it runs normal at highway speeds.
> > I do suspect the fan clutch. During my flush/fill session, it
> > appeared the fan was turning slowly, so I used a piece of 2x4 and was
> > able to stop it. I could hold it still with my hands while the engine
> > was idling with little resistance. The fan clutch was replaced about
> > 2 years ago by an unscrupulous mechanic, It may be defective. But the
> > local CAP auto parts guy says "no" (even though he could have sold me
> > a new one for about $125).
> >
> > Any ideas?
> >
> >
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> > opinions of the author and do not represent those of Open for Business.
> >
> >
>
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