Warm engine, cold heater

This should be an easy one.

My 1993 Sentra XE has fewer than 50,000 original miles.
Lately the temp indicator in the dash either registers very
low or doesn't budge at all.

With the engine warm and the heater full on, the vent air is
only slightly warm. Does that mean the engine thermostat
isn't opening? Or stuck open?

Central Gulf coast area. (i.e. mild temps)

DemoDisk wrote:

This should be an easy one.

My 1993 Sentra XE has fewer than 50,000 original miles.
Lately the temp indicator in the dash either registers very
low or doesn't budge at all.

With the engine warm and the heater full on, the vent air is
only slightly warm. Does that mean the engine thermostat
isn't opening? Or stuck open?

Central Gulf coast area. (i.e. mild temps)

These are typical symptoms of the thermostat being stuck open.
Run the engine with the car stationary, and the engine should
reach operating temperature. If the thermostat has failed
open, the engine (and heater) temperature will drop too low
again within a couple of minutes of moving off at normal
speeds.

I expect your fuel consumption is higher than normal too.

John

John Henderson wrote:

DemoDisk wrote:

This should be an easy one.

My 1993 Sentra XE has fewer than 50,000 original miles.
Lately the temp indicator in the dash either registers very
low or doesn't budge at all.

With the engine warm and the heater full on, the vent air is
only slightly warm. Does that mean the engine thermostat
isn't opening? Or stuck open?

Central Gulf coast area. (i.e. mild temps)

These are typical symptoms of the thermostat being stuck open.
Run the engine with the car stationary, and the engine should
reach operating temperature. If the thermostat has failed
open, the engine (and heater) temperature will drop too low
again within a couple of minutes of moving off at normal
speeds.

I expect your fuel consumption is higher than normal too.

John
You listed the exact symptoms my '92 SE-R exhibited. A new thermostat

cured all that.

"John Henderson" <jhenRemoveThis (AT) talk21 (DOT) com> wrote

DemoDisk wrote:

This should be an easy one.

My 1993 Sentra XE has fewer than 50,000 original miles.
Lately the temp indicator in the dash either registers very
low or doesn't budge at all.

With the engine warm and the heater full on, the vent air is
only slightly warm. Does that mean the engine thermostat
isn't opening? Or stuck open?

Central Gulf coast area. (i.e. mild temps)

These are typical symptoms of the thermostat being stuck open.
Run the engine with the car stationary, and the engine should
reach operating temperature. If the thermostat has failed
open, the engine (and heater) temperature will drop too low
again within a couple of minutes of moving off at normal
speeds.

I expect your fuel consumption is higher than normal too.

John

Thanks, John, very much for posting.

Yeah, I gave the car a warm-up run today and the temperature behaved
just the way you said it would.

Concerning the fuel mileage, well...it's been bad for so long I didn't
even notice. Let's see how it does after a new thermostat.

JPM