Temp gauge

[Jeremy-b]

I have a 01 4.0 4x4. 6 cyl. My temp gauge is taking forever to reach halfway. I have heat. I do need to top off the radiator about every 2 weeks. But no leak anywhere. Inside or out. Eventually it does get there after about 3 miles of driving. And help would be greatly appreciated. Thank you

 

[RonD]

Well there IS a leak, you just haven't found it yet
On the 2001-2011 4.0l SOHC Rangers its usually a crack in the thermostat housing, it leaks on to the top of the engine so evaporates and never makes it to the ground or even where you would see it easily
The Temp sender and temp sensor are BOTH on the thermostat housing, both have 2 wires each
The one with a red/white wire is the sender, for temp gauge on dash, 12volt
The one with grey/red wire is the sensor, for the engine computer, 5volt


As for the temp gauge, 1/2 way is about 200degF
Engine operating temp is 175-185deg with a 190-195degF thermostat, so should show just below 1/2 after full warm up

Depending on OUTSIDE temp, it should take 5 to 8 minutes for temp gauge to reach operating temp, just below 1/2
Coolant temp will be 120degF after 2 minutes, so heater should feel warm after that
Choke mode ends above 150degF maybe 3 or 4 minutes

3 miles doesn't have a time frame, so can't compare it with that, and if it was 3 miles uphill that would warm it up faster, lol, if its downhill then less warm up

 

[DILLARD000]

@Jeremy-b
Ditto on likely ThermoStatHousing cracked+leaking into cave under IntakeManifold & evaporating;
get a good Flash\ShopLight & look closer for a gunky swamp on top of the engine block.
A 20+ year old vehicle: if you've never fully seviced the coolant system, it's way overdue:
~ With vehicle parked\jacked pointing uphill, drain system, refill with distilled water & burp ALL air from system
~ Drive for 30min, then drain again.
~ Remove Hoses from HeaterCore at firewall, foreward+backward flush HeaterCore with a garden hose then compressed air
~ Replace Pump, Fan, FanClutch, SerpBelt, ALL Hoses
~ Consider deleting PCVCoolantLoop
~ Replace junk Plastic HeaterControlBallValve with Metal HeaterControlPlugValve
~ Replace junk Plastic ThermoStatHousing with Aluminum ThermoStatHousing
~ Replace ThermoStat
~ Replace junk PlasticTanked Radiator with AllAluminum Radiator
~ With vehicle parked\jacked pointing uphill, refill with fresh 50/50, & burp ALL air from system
Hope this helps. More details at wiki link below.

 

[Jeremy-b]

Well there IS a leak, you just haven't found it yet
On the 2001-2011 4.0l SOHC Rangers its usually a crack in the thermostat housing, it leaks on to the top of the engine so evaporates and never makes it to the ground or even where you would see it easily
The Temp sender and temp sensor are BOTH on the thermostat housing, both have 2 wires each
The one with a red/white wire is the sender, for temp gauge on dash, 12volt
The one with grey/red wire is the sensor, for the engine computer, 5volt


As for the temp gauge, 1/2 way is about 200degF
Engine operating temp is 175-185deg with a 190-195degF thermostat, so should show just below 1/2 after full warm up

Depending on OUTSIDE temp, it should take 5 to 8 minutes for temp gauge to reach operating temp, just below 1/2
Coolant temp will be 120degF after 2 minutes, so heater should feel warm after that
Choke mode ends above 150degF maybe 3 or 4 minutes

3 miles doesn't have a time frame, so can't compare it with that, and if it was 3 miles uphill that would warm it up faster, lol, if its downhill then less warm up

Thank you for responding. That would explain why I smell coolant once in a while. Is the cracked housing fixable?

 

[JohnnyO]

Thank you for responding. That would explain why I smell coolant once in a while. Is the cracked housing fixable?

No. They're not real hard to change though and they come with a new thermostat inside. A new plastic one from Auto Zone is about $70 or you can get a new aluminum one for about $85 from www.zabteck.com that will last forever. Check your radiator cap, if it is a 20 lb until it is helpful to replace it with one for a 2000 V6 Mustang that is 16 lb.

 

[RonD]

Nice how-to for thermostat housing here: http://howtoreplacefordthermostathousing.com/

BUT............you need to confirm that's where its leaking

Smaller leaks don't leak until cooling system has pressure, and it has no pressure until engine is warmed up, and then the leaked coolant evaporates, so.......................hard to find the leak

You can rent a cooling system pressure tester, some auto parts places "loan" them, or rent them
Its just a radiator cap with a pressure gauge and hand pump attached
You put it on a COLD ENGINE, and pump up the pressure to 20psi
Then watch for dropping pressure and for the coolant to come out, it won't evaporate this time, it will pool up or drip down to the ground

 

[cbxer55]

As far as how long it's taking to warm up, three miles isn't a long time if you didn't warm it up prior to driving it. I warm all my vehicles up a few minutes prior to driving, hence my Ranger is usually fully warm in one mile or less. In the winter, it takes longer though. Although generally, in the winter, I go out, start the vehicle, set the defroster on low, close and lock the door, go back inside. Even at work. Come out to a warmed up vehicle with the windows defrosted.

 

[cbxer55]

This is probably the best metal thermostat housing for the 4.0. The plastic one on my 2007 Mustang was leaking horribly, not just a little leak that evaporated on top of the motor. All over the floor leak. This item is one piece, no joint to cause any troubles. The hardest part of changing them is the little short bypass hose underneath it.

https://simmonsautosportz.com/products/2005-2010-mustang-metal-thermostat-housing

 

[Jeremy-b]

No. They're not real hard to change though and they come with a new thermostat inside. A new plastic one from Auto Zone is about $70 or you can get a new aluminum one for about $85 from www.zabteck.com that will last forever. Check your radiator cap, if it is a 20 lb until it is helpful to replace it with one for a 2000 V6 Mustang that is 16 lb.

Thank you. I’m getting ready to go attempt it.

Nice how-to for thermostat housing here: http://howtoreplacefordthermostathousing.com/

BUT............you need to confirm that's where its leaking

Smaller leaks don't leak until cooling system has pressure, and it has no pressure until engine is warmed up, and then the leaked coolant evaporates, so.......................hard to find the leak

You can rent a cooling system pressure tester, some auto parts places "loan" them, or rent them
Its just a radiator cap with a pressure gauge and hand pump attached
You put it on a COLD ENGINE, and pump up the pressure to 20psi
Then watch for dropping pressure and for the coolant to come out, it won't evaporate this time, it will pool up or drip down to the ground

well after looking around it’s wet in between the upper and lower housing. I guess the gasket is no good. I’m hoping it’s just the gasket. I’m getting ready to pressure test it.

 

[1990RangerinSK]

As far as how long it's taking to warm up, three miles isn't a long time if you didn't warm it up prior to driving it. I warm all my vehicles up a few minutes prior to driving, hence my Ranger is usually fully warm in one mile or less. In the winter, it takes longer though. Although generally, in the winter, I go out, start the vehicle, set the defroster on low, close and lock the door, go back inside. Even at work. Come out to a warmed up vehicle with the windows defrosted.

Modern vehicles do not need to be warmed up before driving. Warming it up is solely for the convenience and comfort of the driver.

My Fit (2010):

• It had remote start. On really cold (or really warm!) days, I'd hit the start button and then put my coat on (or wait 30 seconds in the summer). But that was only for my own comfort
• If it was parked in the garage, or outside and didn't need to be scraped, I'd let it idle just long enough for the idle speed to drop to 1500 (at start it was over 2,000, then drive way.
  • If it needed to be scraped, I'd start it, and use the defroster to help me scrape the windshield. I scraped the side windows while I waited for the rear window to warm up, then scraped it, then scraped the windshield

My '90 Ranger

• If I didn't need to scrape it, i just started and drove way.
• If it needed to be scraped, I'd start it, and use the defroster to help me scrape the windshield. While I waited for the windshield to warm up, I scraped the side windows.

My '95 Taurus is treated the same as the '90 Ranger.

 

[Jeremy-b]

Modern vehicles do not need to be warmed up before driving. Warming it up is solely for the convenience and comfort of the driver.

My Fit (2010):

• It had remote start. On really cold (or really warm!) days, I'd hit the start button and then put my coat on (or wait 30 seconds in the summer). But that was only for my own comfort
• If it was parked in the garage, or outside and didn't need to be scraped, I'd let it idle just long enough for the idle speed to drop to 1500 (at start it was over 2,000, then drive way.
  • If it needed to be scraped, I'd start it, and use the defroster to help me scrape the windshield. I scraped the side windows while I waited for the rear window to warm up, then scraped it, then scraped the windshield

My '90 Ranger

• If I didn't need to scrape it, i just started and drove way.
• If it needed to be scraped, I'd start it, and use the defroster to help me scrape the windshield. While I waited for the windshield to warm up, I scraped the side windows.

My '95 Taurus is treated the same as the '90 Ranger.

Thank you for your response. I do warm it up before I leave. I found the leak. It’s the gasket between upper and lower thermostat housing.

 

[G8orFord]

My 2001 4.0 will warm up to operating temp in about 3-5 minutes at idle in 60-70 degree ambient temp. Fastest warmup I've ever seen on a vehicle. Runs 194-196 on a flat cruise on the interstate.

I think you'll find that what you believe is a gasket leaking is actually a failed plastic weld seam on the housing. If they were going to make it plastic, it probably should have been built in two pieces, but it should have been aluminum from the start. Buy the aluminum one.

 

[DILLARD000]

...My 2001 4.0 will warm up to operating temp in about 3-5 minutes at idle in 60-70 degree ambient temp.
...what you believe is a gasket leaking is actually a failed plastic weld seam on the housing.
...should have been aluminum from the start.

Ditto on all that.
Click here for details of plastic to aluminum ThermoStat Housing swap on my 2001 V6~4.0L~SOHC.

 

[Jeremy-b]

My 2001 4.0 will warm up to operating temp in about 3-5 minutes at idle in 60-70 degree ambient temp. Fastest warmup I've ever seen on a vehicle. Runs 194-196 on a flat cruise on the interstate.

I think you'll find that what you believe is a gasket leaking is actually a failed plastic weld seam on the housing. If they were going to make it plastic, it probably should have been built in two pieces, but it should have been aluminum from the start. Buy the aluminum one.

Thank you for your response. I agree with the leak. I seen some green stuff coming from the gasket. I was gonna change the gasket but your saying isn’t 1 piece. It’s going to the shop Tuesday.

 

[G8orFord]

I'm saying it is one piece. It looks like it's two pieces but it's s actually one that's sonically welded together.