coolant gauge lowers at idle

[sherwoodforest09]

my 1998 4cyl coolant gauge moves below the center even if the truck is hot i work about 50 miles away and ill get to work and sit at idle for a couple of minuets and the coolant gauge drops below the center of the gauge ive never had a problem with the truck overheating or anything
i think it might be the thermostate going but im not sure
any ideas????

 

[modelageek]

my 1998 4cyl coolant gauge moves below the center even if the truck is hot i work about 50 miles away and ill get to work and sit at idle for a couple of minuets and the coolant gauge drops below the center of the gauge ive never had a problem with the truck overheating or anything
i think it might be the thermostate going but im not sure
any ideas????

you are most likely low on coolant, or you have an air bubble. This happened to me. The sensor sits on top of the t-stat housing. if the coolant is low then the sensor is not submerged in coolant. as you increase the rpm's the coolant will be flushed over the sensor and the gauge will go up.........if you replace the t-stat only use the Motorcraft one. it will sit properly in the housing and has the proper bleeder on it......Have you done anything to the coolant system lately

 

[sherwoodforest09]

No I check the coolant weekly and I'm fine the radiator is full and the resivore as well and I haven't changed the thermostat yet I just wanted to see what people thought it could be I was thinking it could be a sensor for the thermostat its kind of a weird problem

 

[modelageek]

No I check the coolant weekly and I'm fine the radiator is full and the resivore as well and I haven't changed the thermostat yet I just wanted to see what people thought it could be I was thinking it could be a sensor for the thermostat its kind of a weird problem

I'll bet dollars to donuts my 1st post is accurate

Have you always had this issue if not when did you get it?
Did you do any work to the truck?

How long does it take for the needle to come down oce the truck is idling. 3 seconds? 1 minute? 5 minutes?

 

[modelageek]

Also you need more details of your truck in the sugnature. Including LOCATION?

 

[modelageek]

I reread your post. You said it takes acouple of minutes to come down. You did not include a Location but I will guess it is a reasonably cold one

 

[kimcrwbr1]

+1 on the t-stat what I think is happening when the engine is ideling it slows the speed of the coolant going through the radiator. The thermostat does two things it lets the engine come up to temp fast then restricts the flow so the radiator can transfer the heat. The fan clutch tries to maintain a steady air flow but if you slow down the flow of coolant the has a chance to transfer out of the coolant. If you have ever tried pulling out the thermostat the engine temp will allways keep getting hotter because the coolant is flowing too fast through the heat exchanger to transfer the heat. Changing the thermostat will never hurt an engine and in general the more expensive the t-stat the better dont skimp on parts!

 

[modelageek]

+1 on the t-stat what I think is happening when the engine is ideling it slows the speed of the coolant going through the radiator. The thermostat does two things it lets the engine come up to temp fast then restricts the flow so the radiator can transfer the heat. The fan clutch tries to maintain a steady air flow but if you slow down the flow of coolant the has a chance to transfer out of the coolant. If you have ever tried pulling out the thermostat the engine temp will allways keep getting hotter because the coolant is flowing too fast through the heat exchanger to transfer the heat. Changing the thermostat will never hurt an engine and in general the more expensive the t-stat the better dont skimp on parts!

I agree with you.swapping out the t-stat would be a good idea but only if you use a motorcraft........I have seen more people put in a new non motorcraft t-stat into these 2.3/2.5 and have bad luck with them. Also we don't know the OP location but these trucks run cold....... the truck could be acting normal.........you could always put some cardboard over the rad

 

[sherwoodforest09]

It was the shop truck for the longest time and I bought it n I didn't have this problem till about last month n its not overheating so I'm not really worried about it

 

[modelageek]

It was the shop truck for the longest time and I bought it n I didn't have this problem till about last month n its not overheating so I'm not really worried about it

Don't worry about it then .........I bet you it is acting normal....these engines run cold........

 

[sherwoodforest09]

Thanks for the help everyone