After driving with the engine warmed up to normal temp (around 200),
when i get stuck in traffic or at stop lights my engine temp slowly
inches up to the 230-250+ range. I've had a new thermostat installed
and had the coolant flushed, but it still does it. The only thing that
seems to lower the temp (while stuck in traffic or idling) is turning
on the heat full blast.

Does anyone have any ideas what could cause this? Probably an
expensive fix....

<paleface23 (AT) gmail (DOT) com> wrote

Well, something isn't letting the radiator blow off the heat.

The heater bypasses the thermostat, so the fact that you had a new
one installed should at least change things.

Is the radiator getting warm? Is it getting hot? It should be getting
hotter than hell when the thermostat opens. If it isn't then either the
radiator isn't getting the hot water due to a thermostat (did you put
in the right one? a wrong one can warp and jam ), a clogged
hose, or or a clogged radiator. If worse comes to worse, you can
pull the hoses and make sure they didn't 'delaminate' on the inside
and clog. Or pull the radiator and make sure you can 'flow' water
through it with a garden hose.

If the radiator gets hot, are your fans turning on? If not, then figure
out why.

It everything 'appears' to be working, pull the radiator and examine
the cooling fins. I had a Dodge where the fins corroded away and
THREE shops couldn't find the problem. Then I went to this little
"Bills Radiator" backyard shop. He took one look and told me it
was the radiator. Pulled it out and all the little 'foils' between the
cooling tubes were corroded so that they were nothing but paint
shells. Amazing the thing didn't leak, but he told me it was something
to do with the 'artificial salt' they used for a couple of seasons here
in Mass.

My Dodge would run just fine on the highway. But idle in traffic
and the temp would start climbing. Fans just can't pull as much air
through as movement.

<paleface23 (AT) gmail (DOT) com> wrote

Is the radiator fan turning on?

Al

Scott,

Its the 3.1L V6. Yeah, i guess i overstated the temp a bit. The
highest i have seen it get to when it rises like that is around 220 or
so.

Next time, I'll put it in neutral and rev it bit like you say (or try
the AC). If those don't lower it, then i might have a bigger problem.


Thanks...


Scott Buchanan wrote:

Which engine?

Your fan should come on at about 220 F and/or when the A/C is on. Does it?
It is normal for temp to rise when the car is moving slowly because of lack
of air flow over the radiator. It should not get as high as you are stating
if the fan is working.

My 95 four cylinder has the thermostat on the inlet side of the engine. It
does the same thing. During the summer when it starts to rise, I'll turn on
the A/C. This turns on the fan and allows more air flow over the radiator
and the temperature will drop.

During the winter I'll put it in neutral and raise the RPM's to about 2000
and the temperature will drop. My theory is since the thermostat is on the
inlet side it is affected by the cold water from the radiator and does not
open up enough to let enough coolant flow and the engine gets too hot where
it measures the temp.
..


<paleface23 (AT) gmail (DOT) com> wrote