Temperature Issues

[Doncan1823]

Hi, I'm new to this forum. I own a '94 Ranger 4x4 4.0 V6 with manual transmision. Is it normal for the temperature gauge needle to always be fluctuating ?? I literally replaced the whole cooling system. New water pump, new water hoses, new 185 thermostat, new thermostat housing, new double row radiator, new fan with fan clutch and flushed the system. The needle is always going up and down from 1\4 to 1\2. Is it normal ?? Also, the heater is not blowing hot or warm air at all and winter is coming...

 

[mn_smokeater]

the temp going up and down? well yes and no. it should go up an down as per running and cooling when shutting off the engine but il assume your seeing it do it alot faster then it should be doing.

you could have some air left in the system and that can mean higher temps until its bleeds out so that could be part of it.

more smarter people should be chiming in here so they can help narrow it down.

 

[adsm08]

Smokes, you are smarter than you give yourself credit for.


There are 2 things that could easily cause the needle to jump like that. Electrical issues, or air in the system. Since it seems to have worked ok before you took everything apart, I'm gonna guess electrical isn't that likely. An electrical issue also won't cause your lack of heat.

Air in the system will cause both. Pop the rad cap off, and see if you've lost some coolant level. If so, top it off, then go drive around the block. When doing this at work I will let it run for 20 minutes in the shop with the rad cap off, top off the fluid with the engine running, then drive 1.5 miles around the block. I usually see a temp spike around .75 miles as the bubble passes.

I go back, shut it down, SLOWLY, key point there, SLOWLY, and with a shop rag open the cap. Be very careful here. Opening it hot is a key to this bleed, but there is a high risk of getting a bad steam burn. Then I top it off again, and go back out and drive about 8 miles round trip and check it again. I usually add about 1 quart (as needed) at this point, and never have any problems after that.

I know it sounds lengthy, but I have used this of many Explorers after rad replacements and it's been 100% successful so far.

 

[mn_smokeater]

Smokes, you are smarter than you give yourself credit for.


There are 2 things that could easily cause the needle to jump like that. Electrical issues, or air in the system. Since it seems to have worked ok before you took everything apart, I'm gonna guess electrical isn't that likely. An electrical issue also won't cause your lack of heat.

Air in the system will cause both. Pop the rad cap off, and see if you've lost some coolant level. If so, top it off, then go drive around the block. When doing this at work I will let it run for 20 minutes in the shop with the rad cap off, top off the fluid with the engine running, then drive 1.5 miles around the block. I usually see a temp spike around .75 miles as the bubble passes.

I go back, shut it down, SLOWLY, key point there, SLOWLY, and with a shop rag open the cap. Be very careful here. Opening it hot is a key to this bleed, but there is a high risk of getting a bad steam burn. Then I top it off again, and go back out and drive about 8 miles round trip and check it again. I usually add about 1 quart (as needed) at this point, and never have any problems after that.

I know it sounds lengthy, but I have used this of many Explorers after rad replacements and it's been 100% successful so far.

your sigged my friend

and to the OP: do this

 

[feellnfroggy]

Hi, I'm new to this forum. I own a '94 Ranger 4x4 4.0 V6 with manual transmision. Is it normal for the temperature gauge needle to always be fluctuating ?? I literally replaced the whole cooling system. New water pump, new water hoses, new 185 thermostat, new thermostat housing, new double row radiator, new fan with fan clutch and flushed the system. The needle is always going up and down from 1\4 to 1\2. Is it normal ?? Also, the heater is not blowing hot or warm air at all and winter is coming...

My 93 4x4 4.0 stays on the left side of the N at all times. It doesnt fluctuate, except as it warms up. Every car I have ever owned stays about steady. The one time my needle fluctuated was because I blew my waterpump, replaced it, and filled it but didnt burp it enough. If there is any air in those lines it will allow for a hotspot, and your needle will fluctuate. wth it cold or mildly warm, remove the cap and turn it on. as it warms up squeeze the upper rad hose a bunch and watch the fluid at the cap. Eventually it will go down a little add some fluid and do this over and over til it dont go down. Then you 'should' have no more fluctuations.

 

[Doncan1823]

Thanks a lot gentlemen. I checked the coolant and indeed still had air in the system. I squeezed the hoses and made the system burp a lot of air. Let's see how my truck behaves now. Thanks a lot for your input.

 

[mn_smokeater]

Thanks a lot gentlemen. I checked the coolant and indeed still had air in the system. I squeezed the hoses and made the system burp a lot of air. Let's see how my truck behaves now. Thanks a lot for your input.

let us know

Welcome to TRS! we hope you will stay!

 

[Doncan1823]

Well so far I have heat again but the oscilation continues. A friend of mine told me that his grandfather had a '94 Ranger like mine but automatic years ago and sold it because of the temperature gauge going up and down all the time since new. So maybe I just need to get used to it as long as my truck does not overheat. I like my truck a lot and want to keep it for a long time.