At what temp does secondary fan turn on?

[dagod16]

I drain coolant to fix lower hose that was rubbing up agains a power steering line.
Refilled fluid.
Now temp sensor barely reads 182.5 which is the first notch below 210.
at that temp the secondary fan comes on.
Maybe i have a bubble?

[msmoorenburg]

I drain coolant to fix lower hose that was rubbing up agains a power steering line.
Refilled fluid.
Now temp sensor barely reads 182.5 which is the first notch below 210.
at that temp the secondary fan comes on.
Maybe i have a bubble?

220

[dagod16]

OK so why does mine turn on at 195 degrees.

Just yesterday all I did was remove the secondary fan and drained coolant and removed lower hose.
Cut lower hose and the reattached, then reinstalled secondary cooling fan.

I even put my old temp sensor back in to make sure I wasn't crazy.

Is it possible that since it is only 65 to 75 out and I am only going 45 mph for 5 miles then stopping that it doesn't have time to warm up?

If so then why when I sit and let it run or sit in my garage does the cooling fan turn on when it reaches 195 degree?

Hmmmmmm

I even let the heat run to make sure I was getting heat out of the heater core and make sure fluid was traveling through it.

Then I checked the AC and it works fine.

Maybe my cooling fan is not working correctly, how do I test it?


I need some more thoughts?

Thanks

Rob

[4.3LXJ]

I think he temp sender or gauge is not being truthful.

[dagod16]

So I put a stove temp circulular thermometer on the engine and lets see, 30 degree difference is a big deal so I should be able to figure it out.

I would also like to add, that I know what 220 or higher feels like, that engine is just smoking hot and my engine when warmed up just feels normal.

The thermostat is supposed to open at 195 degrees since it is a 195 thermostat. Could anything stop it from flowing besides that. The water pump is spinning fine?

[dagod16]

Well this table top temp gauge isn't working.

I attached some pics. Something in the vehicle is not telling me the truth. I let the jeep run for 20 min. The temp gauge says its about the first notch under the 210, which is supposed to be 182.5 degree, right????. This is sitting in my garage running at idle and it is saying182.5 to me and then the secondary fan comes on.

Also is it possible that the fluid is not circulating in my jeep? If so wouldn't that be a thermostat preventing it from circulating?. I installed a new one last year and it was designed to break in the open position. Also shouldn't I feel fluid flowing through the upper hose when I squeeze it. pics attached.
New radiator, new water pump, hoses.

What about the connection to the secondary fan, could I have messed that up somehow and now it is not thinking correctly?

One more thing what is this sensor, could that be the problem.

I have a three hour trip coming up in two days.

[dagod16]

What is this? Is this the air intake sensor? Maybe it is not working correctly?
Just an idea?

The jeep is running fine and putting out cold AC and Hot heat?

Maybe I need to open the little valve on the bottom of the radiator to let some air out instead of just the cap?

[dagod16]

Could I just have a big bubble in the system and it is causing a suction which is not allowing it to register properly?

[abebehrmann]

You have the AC off and the e-fan is running at ~185?

[dagod16]

I have the AC on or off and off and the e fan will kick in at 190 or so.

I just drop 20 mins to Decatur and 20 min back and it was never over heating under the hood. I checked when I reached Decatur and then again when I got home, so the data I am getting is wrong.

I spoke to a mechanic and he said take a test run and sometimes the ecu and the system maybe have been altered some how and it might take a few days fro the ecu to readjust or calibrate back to normal?

Actually on the way back from Decatur My temp gauge was reading right in the middle between the 155 hash and the 182.5 has.

Something is not right!!

[bulrid8]

Bad sensor

Sent from my ADR6400L using Tapatalk 2

[dagod16]

Well I switched out the temp sensor with a different one that was working fine and I got the same result, so I don't think it's the sensor.

Could it be the ECU

[Carves]

OK so why does mine turn on at 195 degrees.

Should be 218*/220* as mentioned above.

How long has it been turning on at 195* ?? ... As there is a dealer mod to vary something about the aux fans operation on 2000/2001 models.


Is it possible that since it is only 65 to 75 out and I am only going 45 mph for 5 miles then stopping that it doesn't have time to warm up?

Those ambients and distance should be more than adequate for "warming up"


Sounds like you have a sensor related issue as mentioned above ... Most likely the connector is not contacting properly. A good clean with contact cleaner and a gentle wriggle fixed some weird temp displays on mine a while back.

Have someone watch the dash gauge whilst your reconnecting/wriggling the sensor.

An air pocket might cause funny temp displays ... i.e. less than actual coolant temps ... but it doesnt explain the lower fan activation temps.

[dagod16]

So maybe clean the connection with some dielectric cleaner and some grease and then maybe wiggle the two wires in and out a bid on the connector it's self.

Ok I will give it a try.

[Mudderoy]

Well this table top temp gauge isn't working.

I attached some pics. Something in the vehicle is not telling me the truth. I let the jeep run for 20 min. The temp gauge says its about the first notch under the 210, which is supposed to be 182.5 degree, right????. This is sitting in my garage running at idle and it is saying182.5 to me and then the secondary fan comes on.

Also is it possible that the fluid is not circulating in my jeep? If so wouldn't that be a thermostat preventing it from circulating?. I installed a new one last year and it was designed to break in the open position. Also shouldn't I feel fluid flowing through the upper hose when I squeeze it. pics attached.
New radiator, new water pump, hoses.

What about the connection to the secondary fan, could I have messed that up somehow and now it is not thinking correctly?

One more thing what is this sensor, could that be the problem.

I have a three hour trip coming up in two days.

That gauge isn't linear. You'd have to hook up an OBDII scanner to get the correct temp, and if the sensor isn't sending out the right voltages it will still be wrong.

[Mudderoy]

So maybe clean the connection with some dielectric cleaner and some grease and then maybe wiggle the two wires in and out a bid on the connector it's self.

Ok I will give it a try.

I highly recommend getting a OBDII Bluetooth nub and the Torque app for your smart phone. It will really help you with seeing what the ECM is seeing and not what the marginal gauges are telling you.

I really thought this was going to be a sensor issue. Maybe it's a bad gauge, bad ground. Weren't you having problems with the cluster going dead?

[dagod16]

So I took it to a mechanic in town. The Jeep had been running for 20 min, plenty of tie to get hot, some of that was driving.

He put the laser temp gun at the thermostat housing and it was reading 167 degrees. So the gauge in the cluster is reading correctly and the temp sensor is reading correctly.

So why the drop in temp.

Have I reached jeep temp efficiency nirvana?

The mechanic said it's better to run cooler than hotter and everything looks fine so why fight it!

[Mudderoy]

So I took it to a mechanic in town. The Jeep had been running for 20 min, plenty of tie to get hot, some of that was driving.

He put the laser temp gun at the thermostat housing and it was reading 167 degrees. So the gauge in the cluster is reading correctly and the temp sensor is reading correctly.

So why the drop in temp.

Have I reached jeep temp efficiency nirvana?

The mechanic said it's better to run cooler than hotter and everything looks fine so why fight it!

At 167 I would wonder if there is any coolant on the sensor, or if the thermostat is ever closing.

[dagod16]

When I take the sensor out cool comes out.

Well the thermostat I have inside is designed to break in the open position.

[Mudderoy]

When I take the sensor out cool comes out.

Well the thermostat I have inside is designed to break in the open position.

Well you can take the thermostat out, but it in a pan of water on the stove with a thermometer and see if it's opening up at the right temp, and closing. I think you might have the running cold issue if the thermostat wasn't even closing.

Personally I'd just replace it.

[dagod16]

Can I wait until I get back from my trip tom? I'm driving six hours.Or do I need to do it right now?

I was wondering if that was the issue?

So instead of over heating and destroying the head gasket, the thermo did what it was supposed to do

Then if that is the problem why does the fan come on at 195 degrees?

[dagod16]

So with help from Mudderoy we were able to figure it out. It ended up being the thermostat. I bought a thermostat that breaks in the open position instead of the closed position. If I bought an old style it could break in the closed position causing overheating. This new type of thermostat will break in the open position so it lowers the jeeps engine temp. Keeps it running without causing damage.

Pics attached.

I have not taken it for a test run yet because it is still curing for a few hours.

On the left is the broken one in the open position, on the right is the new one. They are both the same 195 degree thermostat.

[dagod16]

The high temp gasket sealer instructions say wait 24 hours before use for perfect seal. I'm sure it's fine to drive tom morning don't ya think?

[Mudderoy]

So with help from Mudderoy we were able to figure it out. It ended up being the thermostat. I bought a thermostat that breaks in the open position instead of the closed position. If I bought an old style it could break in the closed position causing overheating. This new type of thermostat will break in the open position so it lowers the jeeps engine temp. Keeps it running without causing damage.

Pics attached.

I have not taken it for a test run yet because it is still curing for a few hours.

On the left is the broken one in the open position, on the right is the new one. They are both the same 195 degree thermostat.

If you're "curing" the RTV, I just put it on and then bolt it down and go. Never had a problem. Now for diff cover I wait the 30 minutes.

[dagod16]

Well thanks for all your help.

I'm gonna test it out soon. I made it finger tight for one hour then a little tighter , not crazy tight but tighter. So now I just need to add fluid.

So what do you think of the new thermostat style.

[dagod16]

Test in progress.

I topped off the anti freeze and started her up.

She is currently at 200 degrees and the E fan has not turned on.


I want to thank everyone for their help.

This website has saved me so much money I almost don't know what to say.

I have also learned how to do so many things by myself without a mechanic at the rate of $95 an hour.

I even cleaned the throttle body a few days ago. I wonder if that will improve the gas mileage.

Next summer I am going to be doing a bunch of things to my jeep.
Brush guard, front springs, rear leafs and when my son gets it in five years he will have a top notch SUV.

[dagod16]

The E fan came on at 210 on the nose. This is in idle in my garage

I shut her off and I will let her cool down a bit before trying to add anymore coolant if possible. Then I will start her up again and take a drive before bed.

[BlueXJ]

Robert you asked several times about a bubble but you have an open system which brings bubbles to the radiator tank and it is easily found by the water level needing to be topped off.
No trapped bubbles in an open system, just in the closed systems.

[Mudderoy]

Test in progress.

I topped off the anti freeze and started her up.

She is currently at 200 degrees and the E fan has not turned on.


I want to thank everyone for their help.

This website has saved me so much money I almost don't know what to say.

I have also learned how to do so many things by myself without a mechanic at the rate of $95 an hour.

I even cleaned the throttle body a few days ago. I wonder if that will improve the gas mileage.

Next summer I am going to be doing a bunch of things to my jeep.
Brush guard, front springs, rear leafs and when my son gets it in five years he will have a top notch SUV.

NAXJA.org did the same for me, so it makes me feel really good that our site has done the same for you!

[Mudderoy]

The E fan came on at 210 on the nose. This is in idle in my garage

I shut her off and I will let her cool down a bit before trying to add anymore coolant if possible. Then I will start her up again and take a drive before bed.

I don't know if this is the "right" way to do this or not, but what I do is fill up the radiator. Leaving the radiator cap off I start the engine.

I let it idle, adding coolant as necessary. Once it gets up to 195 the thermostat opens and the coolant level drops, I fill up the radiator to the top, wait a couple more minutes and cap it! Then I drive it. Oh and I fill up the over flow bottle. If for some reason it didn't get all the coolant it needed when I was filling it, it will after it cools down and sucks it in from the overflow bottle.

I just check the over flow bottle after a day, or so, and top it off as needed.

Cold or hot line depending on when I check it.

[dagod16]

Well you can fill the radiator up with the cap off until it starts to overflow because the coolant is getting hot!! . So we drove three hours to our location and almost the entire reserve bottle was sucked into the system. When I got home I filled the reserve bottle with more coolant, everything worked fine.

But On my trip I found a 1971 Wagoneer at a cheap used car place for $1500 bucks. It was pretty rusted but it would have been fun to play with for a year or two but I passed.

[abebehrmann]

Nice, another problem solved by XJTalk. Congrats man! Just listened to the podcast(s) you were on about a year ago, good stuff! Happy you're still planning on hanging on to your xj and giving it to your son in a few years

[dagod16]

Thanks I'm trying to make it last.