Running cold

[Rockfan1815]

My 96 2.4 allways runs cold. I get up in the morning and 15 min before I leave i start it so it could warm up. In those 15 min it doesn't even get to the bottom of the normal running range(two lines above the 100 mark. When I start driving the temp drops from the cold air moving over the engine. In the morning it is usually 35-40 degrees out. I recently did a tune up, replaced many of the vital sensors, put a new thermistat in(failsafe 180). Any Ideas.

[bballr4567]

It might be that the temp sensor is out. Either that or the guage is messing up for some reason. I seriously doubt that its running that cold after its been on for that long.

Pop the hood and see if the engine is actually putting out heat. Of course dont touch it in case it is really hot and you burn youself. :)

[98GTKid]

^ I agree, my GA is usually around 125-140 after about 3-4 minutes of running.

[tenspeed]

It sounds like the T-stat is stuck open. Do you get any heat from the heater?

[bballr4567]

Originally posted by tenspeed
It sounds like the T-stat is stuck open. Do you get any heat from the heater? Yea but wouldnt it eventually get warmer then 100??

[pokesmot]

Originally posted by tenspeed
It sounds like the T-stat is stuck open. Do you get any heat from the heater?

I second that.

if you get heat from the heater its most likely a sending unit problem.

if you have little or no heat coming through its probably a stuck open t-stat.

another thing to check, is your rad fan always on when you first start the car?

[Rockfan1815]

Its not very hot air. I just changed the t-stat, is there a chance it could be stuck open even if its new. It never got hot enough to where it would fail in the open position. If it is stuck open, is there an easy way to check to see if it is stuck open. I don't think it is because a few months ago I put a t-stat in because the previous owner did have one in it and I was getting a check engine light for it running to cold. I haven't got the code yet after putting one in. Is it bad for the motor to run it cold.

[Rockfan1815]

I checked an the fans arn't running

[Coondog]

Yes it is bad for the engine to run cold all the time. Cold = rich so you will have crappy gas mileage and it will probably eat the cat.

[SE2000]

Try the oldtimer/ diesel trick and block half of the radiator, Take it for a spin and see if it gets warm.

[tenspeed]

Originally posted by SE2000
Try the oldtimer/ diesel trick and block half of the radiator, Take it for a spin and see if it gets warm.

I used to do that when it was real cold out, with carbureted cars. I used a cereal box and the flap went over the top of the radiator. Keep a eye on the temperature gauge and use the heater to draw extra heat from the engine if needed.

[rixGAphx]

'96 2.4;
autotranny or manual?Originally posted by Rockfan1815
....a few months ago I put a t-stat in because .... I was getting a check engine light for it running too cold.
I think this nearly cinches the problem as being a bad temperature sending unit, rather than a faulty t-stat or other actual cooling problem.

Basically, your gage reads cold (and the computer thought so, too) with two different t'stats, the old and the new.

Check your engine ground cable and body ground connection.
Engine temp and oil gages *often* have only one wire from the dash gage to the sending unit, whence the electricity grounds thru the sender to the block.

If the ground return path is oily/dirty/corroded, then the gage (which is actually a voltmeter with a different dialface) will read lower than actual.

This doesn't apply to completely-computerized gages/sending units, which have a hot wire and return wire to the computer.

Are there any other seemingly-unrelated electrical problems with the car?

A new sender is ~$15-25 at Checker, here http://www.partsamerica.com/ProductDetail.aspx?mfrcode=NIE&mfrpartnumber=TS84231&parttype=290&ptset=A

Though I'm generally loathe to throw $$ a problem in an attempt to diagnose it, now seems like an opportune time to spend a few bucks on a highly-proble solution.

[Rockfan1815]

No running cold is the only problem Im having with the car. I recently fixed a major electrical problem where the computer wasn't seeing a signal from the 02 sensor. Its a autotranny.

[Rockfan1815]

I just reread my 2nd post and realized I made a typo, I meant to say that the previous owner did not have a t-stat in the car, and that was causing the engine to run cold and throw a code. I replaced the sending unit when I got the car. Maybe it is just the gauge because I haven't got a code for it running cold and its running the same temp as when it had no t-stat.

[Rockfan1815]

Any ideas??? Its getting colder and I don't want to destroy my car.

[pokesmot]

so you have verified your temp gauge works and is accurate.

the temp gauge never rises much.

then im still leaning towards a thermostat problem; are you sure you didnt install the thermostat upside down, and are you sure its not one of those failsafe models that jams open when it fails?

the only way you can be running so cold is if your thermostat is stuck open and coolant is flowing through the upper rad hose.

or the thermostat is faulty and opens up prematurely. It needs to open up at 195 degrees for our GA's.

[Rockfan1815]

it is a fail safe. The gauge usually rises to it normal range, in the middle when Im in the city for a while or stuck in traffic.

[tenspeed]

It sounds like your thermostat is stuck open.

You don't have warm air from your heater, the temperature drops when you drive, it goes to normal in city traffic, etc.

[Rockfan1815]

unfortunatly it must be the t-stat. I just hate having to change it because of there it is mounted. If it is broke, hopefully autozone will replace it since I only bought it not even a month ago.

[Rockfan1815]

t-stat it was. My fail safe t-stat failed in the open position. The only wierd thing is that it never got hot enough to have to lock. Must have been defective.