Temp Gauge Staying at Cold

[madeinhb]

So a little background. 2 weeks ago the heat was working intermittently. Then it completely stopped putting heat out.

I changed the thermostat but that didn't fix it. Took it a mechanic and they found a good leak in radiator. So I had them replace the radiator. Driving it home, everything worked right. Temp Gauge was normal and it out out heat.

Well last night, went to a buddies house which is a 45 minute drive. The whole way down and the whole way back - the temp gauge moved up slightly would that was it. Stayed at the Cold position the whole time. And the heat coming out was lukewarm at best.

Before taking it back to mechanic - figured I would check in and see if there could be something easy to look at first.

 

[07V8]

Did you use OEM parts?

 

[madeinhb]

Did you use OEM parts?

For the radiator - not sure.

Thermostat - just went to the auto parts store for it.

 

[AuSeeker]

Have you checked your coolant level?

If they didn't get all the air out after replacing the radiator you could be low on coolant now that you have driven it a bit, also if it's low check for leaks just in case that's why it's low.

 

[4x4Homer]

There could be an air bubble stuck in the system. Once your truck is completely cooled off, take off the radiator cap and take a look. If it's not topped off, then air is in the system. Make sure the overflow is full so that when it cools off, it'll suck in any extra fluid it needs. Take a look here for tips on how to bleed air out of your system: https://www.google.ca/amp/www.instructables.com/id/How-to-Burp-your-cars-cooling-system

If you have no air, then it sounds like it could be a thermostat that's stuck.

 

[madeinhb]

There could be an air bubble stuck in the system. Once your truck is completely cooled off, take off the radiator cap and take a look. If it's not topped off, then air is in the system. Make sure the overflow is full so that when it cools off, it'll suck in any extra fluid it needs. Take a look here for tips on how to bleed air out of your system: https://www.google.ca/amp/www.instructables.com/id/How-to-Burp-your-cars-cooling-system

If you have no air, then it sounds like it could be a thermostat that's stuck.

Radiator is full and overflow is topped to the line.

 

[wcjeep]

Have you checked with a Flir or infrared thermometer? Check thermostat housing, radiator, upper/lower radiator hoses.

 

[4x4Homer]

Radiator is full and overflow is topped to the line.

Sounds like a bad thermostat then.

 

[madeinhb]

Well got in to run some errands. Heat seems to be working now. The temp gauge went up some and is now holding steady at this spot.

 

[Montego Murph]

My guess is there was an air bubble trapped somewhere.

May be an old wives tale, but I was taught by an old-school mechanic to drive up a hill (like in a parking garage, etc) as part of the test drive after doing radiator work, and this would help the air bubbles make their way to the radiator & tank.

Again, maybe nonsense, but it sorta makes sense to me.

 

[4x4Homer]

Run the engine cold to warm on idle in your driveway for a good half hour using something like this attached and full, any air bubble should work themselves out : https://www.amazon.com/Lisle-24680-Spill-Free-Funnel/dp/B00A6AS6LY

 

[Rodtheviking]

I have had to in the past get the front end up in the air to get all the air out after a radiator/heater core replacement. I used some auto ramps last time but have used some blocks of wood and even the curb once to get all the air out.

Start with a cold engine, pull up on the ramps or whatever you got, pop off the filler cap and let it idle up to temp with the heater on full, watching the coolant flow in the tank and fill as needed. Once it gets close to temp, cap it and let it sit until cool and try again if needed.

 

[madeinhb]

I was unable to get it in the air but I used my auto start for 20 min yesterday and then again this morning and gauge us now normal. Thanks for the help!!!