Bad thermostat symptoms?

Two symptoms make me wonder whether my 1994 Corolla has a
faulty / sticky thermostat.
First, in cold weather, when I ride at highway speed as the car is
warming up, it seems to take a long time before the car kicks
into its highest gear. I have an automatic, but in cold weather it
doesn't seem to transition smoothly and quickly into its top gear.

Then the other day in the cold weather, the heater just didn't
seem to be blowing out air that was as hot as it should be.

Sometimes the needle on the dashboard thermostat stays
smack on Cold, and sometimes it moves a slight bit above it.

Do these symptoms point to a faulty thermostat?

If so...are there special things to be aware of when replacing
it? I have put one or two in over the years in other cars, but
I've never drained the antifreeze, etc. I've just put the new
thermostat in and topped up the antifreeze. Thanks in advance
for any advice.

"Al" <acunniff@advancedbionutrition.com> wrote in message
news:1165545625.508880.181490@16g2000cwy.googlegroups.com...[color=blue]
> Two symptoms make me wonder whether my 1994 Corolla has a
> faulty / sticky thermostat.
> First, in cold weather, when I ride at highway speed as the car is
> warming up, it seems to take a long time before the car kicks
> into its highest gear. I have an automatic, but in cold weather it
> doesn't seem to transition smoothly and quickly into its top gear.
>
> Then the other day in the cold weather, the heater just didn't
> seem to be blowing out air that was as hot as it should be.
>
> Sometimes the needle on the dashboard thermostat stays
> smack on Cold, and sometimes it moves a slight bit above it.
>
> Do these symptoms point to a faulty thermostat?[/color]

Yes, or a cooling fan that is stuck in the on position. When the engine is
cold, make sure the electric cooling fan is not running.[color=blue]
>
> If so...are there special things to be aware of when replacing
> it? I have put one or two in over the years in other cars, but
> I've never drained the antifreeze, etc. I've just put the new
> thermostat in and topped up the antifreeze. Thanks in advance
> for any advice.
>[/color]

When you remove the old thermostat, note the orientation of the spring and
the jiggle valve, which looks like a piece of twisted sheet metal stuck into
a small hole in the flange so that the replacement one goes back the same
way. Clean the thermostat housing and mounting surface thoroughly, and use
a new gasket. While you're at it, check the condition of the upper and
lower radiator hose and heater hoses.

If the coolant is more than 2 years old, replace it with the correct
concentration of new coolant.

--

Ray O
(correct punctuation to reply)

My 95 1.8 had the same symptoms. The thermostat had a rubber gasket at the
sealing edge of the thermostat that had folded over. the toyota replacement
thermostat did not have that rubber seal. Could have removed the seal, but
for the time spend, I installed the replacement. Well, my son in law did,
but you get the idea.

I still have oil fouling on #4 that started at 5 years and 60k miles (1qt
400 miles, soot on bumper but no visible smoke). Now 11 years and 100k
miles, I just replace plugs ever 10k miles or so when it starts to miss.


"Al" <acunniff@advancedbionutrition.com> wrote in message
news:1165545625.508880.181490@16g2000cwy.googlegroups.com...[color=blue]
> Two symptoms make me wonder whether my 1994 Corolla has a
> faulty / sticky thermostat.
> First, in cold weather, when I ride at highway speed as the car is
> warming up, it seems to take a long time before the car kicks
> into its highest gear. I have an automatic, but in cold weather it
> doesn't seem to transition smoothly and quickly into its top gear.
>
> Then the other day in the cold weather, the heater just didn't
> seem to be blowing out air that was as hot as it should be.
>
> Sometimes the needle on the dashboard thermostat stays
> smack on Cold, and sometimes it moves a slight bit above it.
>
> Do these symptoms point to a faulty thermostat?
>
> If so...are there special things to be aware of when replacing
> it? I have put one or two in over the years in other cars, but
> I've never drained the antifreeze, etc. I've just put the new
> thermostat in and topped up the antifreeze. Thanks in advance
> for any advice.
>[/color]

I had similar symptoms when the thermostat in my Celica failed in the
open position. It was intermittently faulty for about a month and then
failed one winter night. When I got home the fast-idle was on!
The wax capsule was still OK but the valve (which had a rubber seat) had
partially fatigued through and had bent at an angle, so it couldn't
close.
It had a '93 date code on it and was obviously the original.
--
Neil J. Harris

On 7 Dec 2006 18:40:25 -0800, "Al" <acunniff@advancedbionutrition.com>
wrote:
[color=blue]
>Two symptoms make me wonder whether my 1994 Corolla has a
>faulty / sticky thermostat.
>First, in cold weather, when I ride at highway speed as the car is
>warming up, it seems to take a long time before the car kicks
>into its highest gear. I have an automatic, but in cold weather it
>doesn't seem to transition smoothly and quickly into its top gear.
>
>Then the other day in the cold weather, the heater just didn't
>seem to be blowing out air that was as hot as it should be.
>
>Sometimes the needle on the dashboard thermostat stays
>smack on Cold, and sometimes it moves a slight bit above it.
>
>Do these symptoms point to a faulty thermostat?
>
>If so...are there special things to be aware of when replacing
>it? I have put one or two in over the years in other cars, but
>I've never drained the antifreeze, etc. I've just put the new
>thermostat in and topped up the antifreeze. Thanks in advance
>for any advice.[/color]

Sure sounds like it's stuck open. Replace it, you are hurting the
engine this way.
It is very easy to do, and the part is cheap. A cold engine is not a
happy engine.