In Ethiopia fan issue persists but mechanics say with elevation that it's normal here

[Ephry73]

To the OP, think of this as a temperature thing, not an atmospheric pressure thing. Yes, water boils at a lower temperature at altitude, and at sea level at a nice 100 Celsius. Your motor does not care where you are.

The mechanical thermostat does not care where you are. It is made to run and function at a predetermined temperature at which point it opens up and controls the flow as previously described by MrBlaine. With that said, using the altitude logic, the fan should not be running all the time period.

Running without the thermostat will only ruin your motor in the long run as you will be driving it under load without optimal operating temperature controls.

I have driven Jeeps in the Caribbean at sea level and at close to .8km above sea level. No issues running the motor with the stock thermostat and cooling system. When it's hot enough it does what it needs to do.

 

[JPHikr]

I have used this trick for years.
Install a heater core in front of radiator this will give additional cooling.
Plumb it into the heater lines.
My go to core is the rear heater core for Ford vans.

 

[MountaineerTom]

No, the thermostat does not keep the engine at the optimal temp. It controls only the minimum temp that the engine runs at. If the engine tries to run too cool, the thermostat restricts flow to keep the coolant in the block longer. Once the temp is high enough, then the thermostat allows more flow into the radiator.

Thermostat controls the low side, cooling system efficiency controls the high side through capacity and heat extraction.

Yes, thanks for the detail. I should have said it assists in keeping it at optimal temp.

 

[RMETeeJay]

I don't know what an ETC is but I can pass that info on to my mechanic. I already replaced both relays. Nothing changed; same fan behavior.

Engine coolant temperature sensor

 

[qslim]

If elevation was an issue, folks living in colorado or in the Andes in South America wouldn't be able to run their Jeeps. Or folks in the desert for that matter. Please don't fall into that nonsense. You don’t need to modify your cooling system to compensate for hot weather.

True, we camp & ride trails for days here in UT around 8-9k ft, never had a cooling problem.

 

[Ianmark]

At 7700 feet, water will boil at 158 degrees F, compared to 212 degrees. But, a coolant system is a closed system under pressure, atmospheric pressure shouldn't have anything to do with the cooling system overheating.

I would put in a 160 degree thermostat and a higher pressure rad cap. A rad cap of 16 psi will allow coolant (50/50 mix) to boil at 267 degrees F. A rad cap with a pressure of 24 PSI will allow coolant to boil at 280 degrees.

 

[mrblaine]

At 7700 feet, water will boil at 158 degrees F, compared to 212 degrees. But, a coolant system is a closed system under pressure, aop atmospheric pressure shouldn't have anything to do with the cooling system over heating.

I would put in a 160 degree thermostat and a higher pressure rad cap. A rad cap of 16 psi will allow coolant (50/50 mix) to boil at 267 degrees F. A rad cap with a pressure of 24 PSI will allow coolant to boil at 280 degrees.

Nobody with sense should ever take your advice.

 

[Ianmark]

Nobody with sense should ever take your advice.

I should have said 'or' instead of 'and'. Running an engine with a lower thermostat is done all the time, especially in warmer climates. Why do you think they come in different temperatures?

Normally, nothing has to be changed for a cooling system to keep the engine running properly, but if a problem persists, then a lower thermostat can help. A cooling system can handle a pressure change from 16 PSI to 24 PSI without any issues.

Here in Montreal, sitting in traffic for over an hour in the middle of summer can cause the engine to overheat. A lower temp thermostat will help.

 

[MountaineerTom]

 

[mrblaine]

I should have said 'or' instead of 'and'. Running an engine with a lower thermostat is done all the time, especially in warmer climates. Why do you think they come in different temperatures?

They come in different temperature to meet the design parameters of a particular platform. Just so you know, a lower temp thermostat doesn't make an engine run cooler if the system is deficient.

Normally, nothing has to be changed for a cooling system to keep the engine running properly, but if a problem persists, then a lower thermostat can help. A cooling system can handle a pressure change from 16 PSI to 24 PSI without any issues.

If a problem persists, then the problem needs to be found and rectified, not band-aided with a dumb ass mistake.

Here in Montreal, sitting in traffic for over an hour in the middle of summer can cause the engine to overheat. A lower temp thermostat will help.

No, if the system is functioning properly, it can sit in traffic without overheating until the engine wears out. The lower thermostat isn't fixing the problem.

 

[mrblaine]

See, that's why Chris doesn't let me have admin powers because he knows I would ban anyone who posts that.

 

[MountaineerTom]

LOL

 

[Ianmark]

No, if the system is functioning properly, it can sit in traffic without overheating until the engine wears out. The lower thermostat isn't fixing the problem.

Just talking from personal experience.

 

[mrblaine]

Just talking from personal experience.

All putting a lower temp thermostat in does is let the coolant into the radiator sooner. It controls the minimum operating temp of the engine, the radiator and overall efficiency of the rest of the system control the high side. If they work too well (and they do when functioning properly) they overcool, the thermostat restricts flow, the engine warms up to the CORRECT operating temperature.

 

[scottgraham]

So what I'm gathering is the '06 2.4 has elec fan?
Googled it, NM.

 

[Jeep in Ethiopia]

@Jeep in Ethiopia Please send me your vin number to check build and software for your Jeep. Is it an automatic or manual?

I will get back to you shortly about the fan and altitude once I double check with my technician.

I've private messaged you the VIN #

 

[MrMark52]

I have not looked if your Jeep has one yet (you say Jeep Liberty in your initial post, but your profile says 2004 TJ) - but FYI - my 2003 Grand Cherokee had a solid state relay that powered the fan on/off. That relay had a habit of failing "shorted", meaning the fan continued to run regardless of whether the key was on or off, or if the engine was running or not, or was hot or cold.
The brilliant Engineer's at Jeep chose to locate that relay behind the passenger front headlight in such a way that you had to remove the bumper to replace it - unless you learned the trick of removing the headlight and drilling a hole in the plastic guard behind the headlight. You could then sneak a long handled but driver into the exposed cavity to remove the screw holding the relay, pull it out from behind the grille, unplug and replace, and then sadly (due to wire harness length) you had to reinstall back into the original location.
A scanner will not show this failure. A dead battery will. Trust me on this!

FWIW - the function of a thermostat is to cause the engine to warm up as quickly as possible (and is typically is fully closed at human survivable/normal living temperatures), and then to maintain an internal engine temperature which insures the cleanest, most efficient burning of fuel (which I believe 200-210 degrees F).
When the engine starts engine coolant around the cylinders begins to warm until the water near the thermostat is warm enough for the bi-metal to start expanding, thus slowly opening the stat and allowing cold water from the radiator to start bleeding and mixing in with the warmer water in the engine. Depending on the ambient air temperature and engine load, the stat may not ever open fully - in fact, it is very likely that if it does, you're either low on coolant, the coolant doesn't have good heat transfer properties, the water pump isn't pumping, you've got a collapsed hose (radiator or possibly, but unlikely, heater), or the radiator is clogged - as I doubt the engineers designed the cooling system that close to matching heat generation rate versus heat rejection capability.

Just some thoughts - and note that altitude plays no more a part in this does than does the thickness of tread on your tires - because for as much as the fact that water boils at a lower temperature at a higher altitude, the air is also less dense which means a lessor ability to remove the generated engine heat.
Don't walk, but RUN, RUN, RUN LIKE THE WIND! from anyone suggesting that your Jeep needs a lower temp stat - and is also implying that all the other radiated engines in the area have all had their t-stat's replaced as well. CRAZY!

Follow the wiring out of the electric radiator fan motor and look for a solid state relay. I did a search in the parts book for my '03 Wrangler - although it indicates the relay only for the 2.4l engine (but it's a Wrangler book, not Liberty). It looks like this -

And BTW, it is possible that the radiator fan motor caused the relay to fail. Only use a MOPAR part to replace the one you have, and if it fails within a few months, replace the radiator fan motor when you replace the (now newly failed) relay.

 

[mrblaine]

When the engine starts engine coolant around the cylinders begins to warm until the water near the thermostat is warm enough for the bi-metal to start expanding, thus slowly opening the stat and allowing cold water from the radiator to start bleeding and mixing in with the warmer water in the engine. Depending on the ambient air temperature and engine load, the stat may not ever open fully - in fact, it is very likely that if it does, you're either low on coolant, the coolant doesn't have good heat transfer properties, the water pump isn't pumping, you've got a collapsed hose (radiator or possibly, but unlikely, heater), or the radiator is clogged - as I doubt the engineers designed the cooling system that close to matching heat generation rate versus heat rejection capability.

This may help some-

 

[MrMark52]

This may help some-

”How It’s Made” - Great program!

 

[JC123]

removing the thermostat appears to be common practice in that part of the world: before I bought it from my sister, my 2000 TJ spent its previous 5 years in Abuja, Nigeria. When it turned cold that first fall I had no heat and went to replace the thermostat. I had my son help and assumed he didn't know what he was doing when he told me he didn't see the thermostat. turns out it wasn't there. (which doesn't mean he knew what he was doing but I appreciated that he was doing it with me).