Jeep Wrangler TJ overheating - New day new story

[syed salman raza]

My wrangler TJ is showing getting over heated just after driving 15 km on road at 90 km/hr where coolant level is full

any advise ,cooling system flushed and new coolant added yesterday by workshop

[sertac]

1 hour ago, syed salman raza said:

My wrangler TJ is showing getting over heated just after driving 15 km on road at 90 km/hr where coolant level is full

any advise ,cooling system flushed and new coolant added yesterday by workshop

Your radiator can be clogged. Flushing it is not helping sometimes you need to change it. 

[desertdude]

It's a jeep. It's supposed to overheat.

[Barry]

Is it overheating or running hot? 2 different things. 

[syed salman raza]

with Aircon going more than 110

[Gaurav]

Cooling system overheating on tarmac is a sign of overall cooling system inefficiency.

My best guess is probably it has some air pocket as you mentioned recently topped up with new coolant, so probably mechanic didn't bleed the air bubbles out.

You should do this first by yourself. Open the radiator cap when car is completely cold, top up the coolant in radiator if it's low, then start the car and let little bit of coolant overflow from the open radiator cap. This way some air bubbles might escape the cooling system. Ideally less than 5 min with open radiator gap is good enough and then close the cap. And drive for 30 minutes to let jeep reach its ideal temperature and then switch off the car. Let it cool off for an hour or two, do again same exercise for 2 or 3 times until air bubble stop coming out from the open radiator cap.

P.S. If too much coolant comes out as soon you start the car, switch off and show it to mechanic, there is something more serious that need to be checked with "competent" mechanic.

P.S. 2. NEVER EVER open radiator cap when car is hot. Let car sit for an hour or two before opening the radiator cap.

 

If after this bleeding the coolant system, still car overheat on the tarmac, let us know how high it goes. Ideal Jeep wrangler sits at 200 degrees Fahrenheit = 98.8 degrees Celsius. Little movement (upto 10%) with AC on while slow speed in this peak summer is borderline acceptable,if it shoots beyond 10%, do not drive.

Check without AC while on tarmac if it stays fine then it needs better air circulation and need additional fan. I guess @Wrangeld recently got AUX fan installed, so do the same from any workshop near you. It's the easiest and fastest fix.

Secondly, you can get the viscose clutch fan direct by some turning guy, so it will always run at idle rpm and providing better cooling.

[syed salman raza]

@sertac this is what workshop diagnosed today,   thursday they clean and flush cooling system and said nothing

@Gaurav thanks for detailed advise ,Car is with workshop now will check with them for all instructions.

[Gaurav]

Great, while at workshop ask them to do the radiator clutch fan direct as that will help a lot, as in aged cars many times viscose clutch doesn't engage in right time and keep turning fan at half the rpm when engine need better cooling at full rpm (as per actual design of clutch). And this thing is almost impossible to trace by the many mechanic here. 

So the 5% extra noise of clutch fan is better than cooking your engine and moreover its your offroad vehicle so better cooling is always advisable to have great performance.

[desertdude]

I disagree totally, if the normal temp is around a 100 degree then 110 and that too in his summer heat is acceptable and within operational range. Unless specified otherwise by Jeep.

Second never ever direct you fan clutch. You will be robbing your car of massive horsepower, increase in fuel usage and extra stress on pulleys and tensioners. Not to mentions it's will howl like a banshee all the time and the faster you go the louder the howl

Clutch fans are there only to assist in airflow when the car is moving slow or standing and not enough air is flowing through the radiator once car starts moving above certain speed fan is no longer needed and disconnects. If the car is overheating " 

Making a fan direct is just a band aid temp fix. Better to replace the clutch. Fan has no role to play in cooling the car at speeds like 90.

If it really is overheating at 90 then sertec is probably right. It's a clogged rad.

[Gaurav]

@desertdude it's an industry MYTH that you are referring to and I have done my extensive research based on calculations and data before suggesting this.

Viscose clutch fan direct will take max 2-5 hp additional and won't scream or howl as you are mentioning.

I am using direct clutch fan since 5 years, especially for off-road vehicle with older cars - that's the bestest and bomb proof solution to keep borderline 4x4 run cooler.

On the contrary 4x4 will loose tremendous HP if its overheating or "RUNNING WARM" as oppose to less 2-5 HP used by clutch fan.

Bigger tires probably slows down more by adding several kg extra weight on all 4 axles than this clutch fan load.

Offroad tires makes more noise on highway than this fan clutch howling (so called).

I was like you too scared of all these before going this route and I havent "noticed" any big change in noise level or climbing faya from front face, before and after this change.