Overheating-Maybe issue

[Reno Computer Repair]

Last week I was doing Peavine and the temp went about 10-20% over the normal temp.

This week with wonderfull heat wave I was running 220 to 230 just driving around town, and it would go over the 210 halfway mark in heavy traffic or at traffic lights.

I took it to my mechanic and he told me I was smoking crack :nono: and this was ok.
But my other Jeep (90 Cherokee) does not got over the 210 mark in the same conditions. I just am worried that I may cook it.

So what is the group consensus? I am thinking about adding an electric aux fan to the radiator to get more airflow when I am crawling up hills. I also changed the thermostat about two months ago....

 

[DBXJ]

ahh i had some cooling issuse not like that though just my AUX. fan wasnt comming on when it was supposed too well then i built a relay switch to over ride the fan meaning i can have it on with out the A/C on
now did u flush the radiator and what not when u swaped the thermostat
and if u dont have an aux fan i suggest kragens they have the fan that works perfectly and there relitivly cheap

 

[Connect]

Does it not have an Aux fan on it already? I suppose a higher flow one would help the problem. Or like dbxj said have it on a switch to run continuously off-road.

I think 220 or so is normal for this heat, just make sure you don't get past the red line too far cause aluminum heads means warpage.

does anyone else notice that jeeps have a bad cooling problem for being a low-speed AT vehicle

 

[JOE THE TOE]

In-line4.0 Never Gets Above 210 , If It Does You Got Problems.

 

[Connect]

well not quite 210, I think thats average on a 70 degree day. But much higher then that and yes you got problems.

 

[DBXJ]

hmmm well my all cast iron 4.0 has never gotten abouve 210 ever even in this heat there might be a clog i his cooling system somwhere or his mixture is off the other thing is that u might need to run some sort of water pump lubricant through the system it'll help with the cooling issues

 

[JOE THE TOE]

If He's Changed The Thermostat & It's Still Overheating It Probably Just Needs A Flush Or Possibly A New Radiator.i Bough A Radiator From Performance Radiator Here In Town & Have Never Had A Problem Overheating,i Think It Was Only $125.

 

[Reno Computer Repair]

The Jeep dealer here did the Tstat. Do not think they flushed it. I could not find an aux fan on this, just the main clutch fan...seems weird.

So I will flush it, try it for awhile. If that does not cure it I will by a new radiator, and then how/where do I attach an aux fan?

Also, this is with the a/c on, but damn, my other jeep never goes over 210 even when climbing steep @ss inclines in the heat with the a/c on.....

 

[DBXJ]

well go to kragens they have i think it was a 8" fan it has the complete kit if its not the right size just take it back if u need some help let me know ive already done this before

 

[Reno Computer Repair]

I'll give the fan a try if the flush does no good.......

 

[MR.ROCKAPE]

Adding a electric fan to a jeep that did not have one originally is a band aid to the problem.Is the fan clutch working??Have you taken a surface thermometer to the upper and lower radiator hoses and measured a difference??How old is your water pump??Is your gauge accurate??
Outside temperature should not effect your engines temp on a properly working cooling system.The right way would be to diagnose the problem,not just try things until its fixed.(That gets expensive)

 

[DBXJ]

well with mine i had to replace the oiginal fan because it stopped working pearsonally i would start withy the flush your supposed to fo that after u replace any part of the cooling system in which u need to run an radiator flush through it for a little bit so u get every little bit of build up gone and it gets any clogs out of the system this would probly be the cheapest way to go first
now with out side temp ot effecting it thats true but when there is little space for heat to escape it helps

 

[Reno Computer Repair]

heat

I will flush the radiator on wed and see if that helps, and measure the temps on the upper and lower radiator hoses. Will give you all an update then, and thanks for all the help, because as all you know (unlike my mechanic) I do not smoke crack...... :nono:

 

[Sauce]

I would take rockapes advice far before DBXJ's, rockape was a mechanic at the honda stealership and still does it for a living...

 

[DBXJ]

yea davidt and ive built hotrods since i could remeber and ive delt with reno jeep before they'll usally just add some water istead of putting new fluid in it now u know why our grand cherokee has issues
that and once and iff he flushes the system he can probly find all the gasket seal stuff in there too this helps clog the radiator

 

[rusty_tlc]

Adding a electric fan to a jeep that did not have one originally is a band aid to the problem.Is the fan clutch working??Have you taken a surface thermometer to the upper and lower radiator hoses and measured a difference??How old is your water pump??Is your gauge accurate??
Outside temperature should not effect your engines temp on a properly working cooling system.The right way would be to diagnose the problem,not just try things until its fixed.(That gets expensive)

That just sound like good advice in general. In addition to the expense you might "fix" the symptom but not the problem.

 

[Reno Computer Repair]

The Answer

We finally found the cause of the overheating issue. It was NOT the thermostat or clutch fan. It was the radiator. So everyone write this down in you books:

Take a kitchen thermometer and hold it at different sections of the radiator, going across in one inch stops, across the entire radiator. Note the readings.
If some spots are 140, and other spots 210, then you have a clogged radiator. Mine ended up beyond repair, so they installed a new one.

Thanks again for all the input :wave:

Kevin

 

[DBXJ]

well glad u got it fixed hor it didnt cost u to much

 

[Sauce]

how do you tell if the fan clutch is working?

 

[rusty_tlc]

Link to test look in section 9.1