Low speed fan sensor on 5.9 is dead.. How do i fix this ? - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Grand Cherokee & Commander Forums > ZJ Grand Cherokee Forum > Low speed fan sensor on 5.9 is dead.. How do i fix this ?

Savvy FOX IFP 4" Lift Shocks in StockSavvy/Currie Aluminum Control ArmsSavvy Aluminum Gas Tank Skid

Reply
Unread 03-22-2013, 03:12 PM   #1
Candymancan
Registered User
1998 ZJ 
 
Join Date: Aug 2010
Location: Virginia
Posts: 3,852
Low speed fan sensor on 5.9 is dead.. How do i fix this ?

Hey guys, I replaced my motor in my fan i think last year spring or so with one of those from the auto parts stores and a ford pigtail because the bearings in my old fan went bad.. Been working fine since until the last 1-2 weeks.. My engine i noticed has been idling high and for a second i thought it was my TPS or something but apon looking at my temp gauge my temps were at the 210f mark and higher.. Seems the engine idles higher once it reachs the 210f mark probably for the clutch fan to spin faster if it had one.. Well anyway i watched the temps and they crept up to the 220f mark and then the high speed kicked on and cooled it back down to the 210f mark and then turned off, and went back to 220f and high speed came on and so forth..

If i turn my A/C on the low speed comes on for a second or two but then comes off, and then it comes back on a few seconds later and again 1-2 seconds then turns off.. Im not sure if thats normal for it to come on and off for that short amount of time or not.. So i unplugged my low speed harness on the upper rad hose and then plugged it back in and boom it comes on and cools down to 200f and shuts off like it usually does.. but then it rises back to near 220 before the high speed kicks on.. So i unplugged it again and jumped it with some wire and it comes on and stays on until i remove the wire..

So im guessing this means my sensor on the upper radiator hose is starting to go bad ? Working only occasionally.. I read over while browsing this and jeepforum over the years that they dont sell new sensors and what kinda pisses me off is 3 weeks ago i was a salvage yard and they had a wrecked 5.9 there.. I got the TPS and IAC and amp out of it but didnt need anything else however i didnt think to take the fan sensors because i wasnt having this issue at the time


So what can I do ? I heard swapping the high and low speed sensor will fix this ?? Is this true ?


EDIT: After some searching i found this sensor from another forum.. Napa part # ECH TS4015 It does look exactly like the one we have in the 5.9 people said they used it and it works.. they say it turns on at almost the same temp as the stock one.. But I want to know what you guys think

http://www.napaonline.com/Catalog/Ca...015_0366163310

__________________
2013 6.2 V8 Camaro SS 4k miles
1998 5.9 V8 ZJ 160k miles
1998 4.0 I6 Laredo ZJ 210k miles
Candymancan is offline   Reply With Quote Quick reply to this message
Unread 03-22-2013, 04:09 PM   #2
McCloudsZJ
Because RaceJeep
 
McCloudsZJ's Avatar
1998 ZJ 
 
Join Date: Sep 2011
Location: Roanoke, VA
Posts: 2,676
I know I've read about people replacing them with an aftermarket sensor with great success. It might be the one you posted. I'll poke around and see if I can find those threads again.
__________________
March 2014 GCOTM. 1998 Deep Slate 5.9
On the Jeep:Hot intake, 52mm TB, Summit 8mm wires, catch can, 703s, insulated fuel rails, indexed Champions, Bilstein 4600s, Eibach lowering springs, Moog SS, Ironman mounts, Lotek 2GP, lots of gauges, sparkly paint.
In the garage: M1 4bbl
In the works: Addco/Hellwig sway bars, nitrous, full polly bushings, full exhaust, data logging, billet UD pulleys
McCloudsZJ is offline   Reply With Quote Quick reply to this message
Unread 03-22-2013, 05:10 PM   #3
Candymancan
Registered User
1998 ZJ 
 
Join Date: Aug 2010
Location: Virginia
Posts: 3,852
I just tried to remove the low speed sensor on the upper hose.. it wont unscrew... Its like welded on from years of hot an cold... I took the whole tube thing off the upper hose so i could get more leverage to unscrew the sensor... it will not come off.. tried heat, tried pd blaster.. uhg what a pain in the ***..

Do you know if they sell that black t line fitting as well as the sensor ? I might have to replace both because i cant get the sensor to unscrew..
__________________
2013 6.2 V8 Camaro SS 4k miles
1998 5.9 V8 ZJ 160k miles
1998 4.0 I6 Laredo ZJ 210k miles
Candymancan is offline   Reply With Quote Quick reply to this message
Unread 03-22-2013, 05:21 PM   #4
Candymancan
Registered User
1998 ZJ 
 
Join Date: Aug 2010
Location: Virginia
Posts: 3,852
So does no one know what sensor to buy that will replace this one ??? I also seem to need an Inline radiator hose adapter for it... Since I cant get the old sensor off mine
__________________
2013 6.2 V8 Camaro SS 4k miles
1998 5.9 V8 ZJ 160k miles
1998 4.0 I6 Laredo ZJ 210k miles
Candymancan is offline   Reply With Quote Quick reply to this message
Unread 03-22-2013, 05:30 PM   #5
PolkaPower
Registered User
1998 ZJ 
 
Join Date: Aug 2011
Location: The Abyss, Italy
Posts: 16,496
I think I saw that Cameleer bought a set of those as extras from someplace. Maybe a dealer that had old stock. They were expensive and I believe it came with the T fitting.
PolkaPower is offline   Reply With Quote Quick reply to this message
Unread 03-22-2013, 05:33 PM   #6
Candymancan
Registered User
1998 ZJ 
 
Join Date: Aug 2010
Location: Virginia
Posts: 3,852
I would be happy simply switching my high and low speed sensors as i hear they are the same... but i cant even get the damn sensor to budge.. Its on so tight its smushing the brass where my wrench goes.. Cant drive the Jeep now.. checked the temps with my OD2 reader it gets to 225f before the highspeed kicks on.

Wish this problem happend when if ound that 5.9 in the JY... gah this sucks
__________________
2013 6.2 V8 Camaro SS 4k miles
1998 5.9 V8 ZJ 160k miles
1998 4.0 I6 Laredo ZJ 210k miles
Candymancan is offline   Reply With Quote Quick reply to this message
Unread 03-22-2013, 07:51 PM   #7
newfieZJ
Registered User
1995 ZJ 
 
Join Date: May 2008
Location: , Alberta
Posts: 6,511
Put it in a vice , only do so arount the nut portion shown in the pic . If your not worried about the sensor since it's now likely stripped , use vice-grips and tap them with a hammer .

If that doesn't work , heat it , then when it's hot , pour water over it to 'shock' the corroded connection , that always works . I had to do this today trying to remove the 02 sensor from a cat w/180+k , it was the only thing that worked too .

If that fails , what is one worth to you ? Bear in mind , I can't control shipping costs from Canada
dsc06031.jpg  
newfieZJ is offline   Reply With Quote Quick reply to this message
Unread 03-22-2013, 10:41 PM   #8
jenniferny
Registered User
1998 ZJ 
 
Join Date: Mar 2009
Location: Lockport, NY, New York
Posts: 144
Quote:
Originally Posted by Candymancan View Post
Hey guys, I replaced my motor in my fan i think last year spring or so with one of those from the auto parts stores and a ford pigtail because the bearings in my old fan went bad.. Been working fine since until the last 1-2 weeks.. My engine i noticed has been idling high and for a second i thought it was my TPS or something but apon looking at my temp gauge my temps were at the 210f mark and higher.. Seems the engine idles higher once it reachs the 210f mark probably for the clutch fan to spin faster if it had one.. Well anyway i watched the temps and they crept up to the 220f mark and then the high speed kicked on and cooled it back down to the 210f mark and then turned off, and went back to 220f and high speed came on and so forth..

If i turn my A/C on the low speed comes on for a second or two but then comes off, and then it comes back on a few seconds later and again 1-2 seconds then turns off.. Im not sure if thats normal for it to come on and off for that short amount of time or not.. So i unplugged my low speed harness on the upper rad hose and then plugged it back in and boom it comes on and cools down to 200f and shuts off like it usually does.. but then it rises back to near 220 before the high speed kicks on.. So i unplugged it again and jumped it with some wire and it comes on and stays on until i remove the wire..

So im guessing this means my sensor on the upper radiator hose is starting to go bad ? Working only occasionally.. I read over while browsing this and jeepforum over the years that they dont sell new sensors and what kinda pisses me off is 3 weeks ago i was a salvage yard and they had a wrecked 5.9 there.. I got the TPS and IAC and amp out of it but didnt need anything else however i didnt think to take the fan sensors because i wasnt having this issue at the time


So what can I do ? I heard swapping the high and low speed sensor will fix this ?? Is this true ?


EDIT: After some searching i found this sensor from another forum.. Napa part # ECH TS4015 It does look exactly like the one we have in the 5.9 people said they used it and it works.. they say it turns on at almost the same temp as the stock one.. But I want to know what you guys think

http://www.napaonline.com/Catalog/Ca...015_0366163310


I have used BWD Automotive WT3000Z very successfully to replace both my upper and lower sensor. It is supposedly a lower temp item. I think it was from a 86 or 87 Buick Grand National if memory serves.

Also, since your old sensor is bad, you might try putting a deep socket, a little smaller than the sensors nut, on the top of the sensor nut and tapping it briskly, just tap only as hard as you have to to break the corrosion loose. You may have to break of the plastic wiring connector. I would also use PB Blaster sprayed on the threads and let it set for hours to a day or two or three adding mor PB Blaster periodically to let it soak well into the threads. Then, when you are ready to start, spray it again and add more PB Blaster every few taps. Just use a small hammer, a small "Dead Blow" hammer would be best because it transfers more of the energy to where you want it to go. A small hammer will make fatal damaging blows more difficult. More firm but not over zealous taps rather than a few very hard blows should not damage the housing. Start out with lighter taps to learn what the housing will tolerate and work up slowly and gradually until you feel you might do damage, and again omly clamp th large housing nut in the vice and do not tighten it to much or you could possibly crack it.

Has anyone ever been able to find a spec sheet for Coolant Sensors by Part #?? This information use to be available in the back of printed catalogs and I would spend hours going through the spec section to find the exact spec I needed for what ever part I wanted to change the spec on, like Vacuum Advance on an HEI Distributor so I could run more and faster centrifigal advance without creating to much total advance and bring it in at the RPM I wanted it for example. Today paper catalogs are virtually non-existant. Ive even written to a number of companies with specific Part #'s and asked what the specs were. I always receive just dimensions back. When I ask for more detailed and specific information the responses I have gatten tell me the person answering has no idea whatsoever what I am talking about and very obviously also has no automotive background whatsoever. I would love to find a spec listing for coolant temp sensors so I can modify the temperature which my cooling fans come on to keep the temperatures as stable as possible and keep the temperature 15-20 degrees cooler at full operating temperature in warm and hot weather. Does anyone know where this information can be found?? I would gladly share the information with anyone that wanted it and do all the research myself to find just the right sensors and then do the initial testing to make sure I got the right end result. I am disabled, so I have a lot of time on my hands and really enjoy problem solving like this. It is why I was so valuable to the company I worked for before I was injured. I was relentless and never would give up until the problem was solved. Also, I am weak in electrical. Where can I find how to use a multimeter to test sensors and teach me how to determine what the specs are. If there is another way or a better way than a multimeter, what is it?

Hope this helps
__________________
Jennifer
jenniferny is offline   Reply With Quote Quick reply to this message
Unread 03-23-2013, 01:42 AM   #9
Candymancan
Registered User
1998 ZJ 
 
Join Date: Aug 2010
Location: Virginia
Posts: 3,852
I dont have a vice but i think the Firestation does.. Ill go there tomorrow after my CPR class and see if they do and ask if i can work on my Jeep there.. They usually always allow people to bring their cars in the bay if they have room and work on em lol. One of the perks to being a Firefighter lol.

I im just not sure if this sensor will work right http://www.napaonline.com/Catalog/Ca...015_0366163004 worried the activiation temp for the fan is too low.. i wish they would tell you what it is.. Aparently after searching its the same sensor used in GM vehicles.. another model number for it would be SU109 http://www.bestliquidations.com/Coolant_temp_TX3.htm

So i dont think this will work... :/ heard the SU109 people used and it activates too early at like 200f i believe.. so ppl say it will only work good with a 180f thermostat.. I dont mind replacing my thermostat i need to get a new gasket on that thing anyway but why would I want my motor to run cooler.. wouldnt that make it burn more gas
__________________
2013 6.2 V8 Camaro SS 4k miles
1998 5.9 V8 ZJ 160k miles
1998 4.0 I6 Laredo ZJ 210k miles
Candymancan is offline   Reply With Quote Quick reply to this message
Unread 03-23-2013, 02:50 AM   #10
jenniferny
Registered User
1998 ZJ 
 
Join Date: Mar 2009
Location: Lockport, NY, New York
Posts: 144
Electric Fan Sensors

Quote:
Originally Posted by Candymancan View Post
why would I want my motor to run cooler.. wouldnt that make it burn more gas
Lowering the temp helps to prevent pinging, hot spots in the Cyl head/combustion chamber. and allows more performance mods. I have a performance tune in my ECU and I must run 93 octane and a 180 thermostat, cold air intake, yadda, yadda, yadda or it pings away pretty bad. If you have no performance mods and dont plan any it is not as critical. Most car manufacturers keep the operating temps pretty close and pretty high to get the best possible emissions, but in the real world running your engine a little cooler is usually OK and many times beneficial. From the factory the 5.9 Limited has the hottest factory tune to date in a 5.9 Magnum and other performance items unique to the 5.9 Limited, that is why they all ran so good, but there was a lot of room for more tweaking. If some sensors lower the on temp for the fans, it is most likely a very small difference, I notice no difference at all in my temp gauge, but sometimes all that is needed is a small change to make things better. Now, with the AC on, and on the hottest days, I do notice I have little to no pinging since using the new sensors.
__________________
Jennifer
jenniferny is offline   Reply With Quote Quick reply to this message
Unread 03-23-2013, 03:16 AM   #11
Candymancan
Registered User
1998 ZJ 
 
Join Date: Aug 2010
Location: Virginia
Posts: 3,852
Well, I do ping, but i burn a quart of oil every 3k i havent fixed my plenum assuming its bad even tho the pan is clean from back to front i even had the dealership use a camera in my intake and they saw no oil. So i dunno where my oil loss is comming from if it isnt that.... But still if the computer is tuned to run at XX temp and you use a 180f therm wouldnt this cause it run in a open loop and burn more gasoline like if it were cold and running rich... I do use the same air filter setup you have but i dont see where a 180f thermostat would help as far as pinging goes or help on gas mileage.. The engine doesnt run that hot anyway according to a OBD reader it reachs about 213f at the sensor on the engine before the low speed fan kicks on and brings it down to 200f before shutting off.. Hense why the temp gague on a 5.9 always reads on the notc below the 210f mark... Using a 180f thermostat to me would seem to make it 15f cooler.. Specially if you use one of those switchs that activate at 195f vs 213f. Also as far running cooler and gas goes.. i tried running a cooler plug before and saw no help as far as pinging goes but i did see a drop in gas mileage.. Now using a 180f with a stock sensor doesnt seem like it would do anything as the fan would still come on at 213f..

The sensors all seem to activate at 195f.. Hense why i havent seen a replacement sensor for ours. I call a 18f activation temp a big diff.. Thats why i said ppl say it keeps the fan on 24/7 which isnt good for the fan motor.. Now that would seem good for the tranny if you wanna keep that cool lol.. but yea


As for pinging... my engine doesnt ping in the summer on hot days.. It pings in the winter which i find completetly oposite from what most people mention on this forum.. including you which i never understood.


Newfire as for what that thing is worth it me... Nothing right now because it seems all the switchs out there activate at a cooler temp then our stock ones keeping the fan on 24/7 so i dunno what im gonna do... Seems the only option is to swap the lower hose sensor to the upper one but if i cant get the thing out of the t fitting... I was kinda not wanting to remove the lower Tfitting and drain all my coolant..

Maybe I'll pay a visit to the salvage yard again.. The one about 40m away from me.. According to the 3-19-2013 list they have about 6 98 Grand cherokee's that are black/white so hopefully one will be a 5.9
__________________
2013 6.2 V8 Camaro SS 4k miles
1998 5.9 V8 ZJ 160k miles
1998 4.0 I6 Laredo ZJ 210k miles
Candymancan is offline   Reply With Quote Quick reply to this message
Unread 03-23-2013, 05:17 AM   #12
jenniferny
Registered User
1998 ZJ 
 
Join Date: Mar 2009
Location: Lockport, NY, New York
Posts: 144
Quote:
Originally Posted by Candymancan View Post
Well, I do ping, but i burn a quart of oil every 3k i havent fixed my plenum assuming its bad even tho the pan is clean from back to front i even had the dealership use a camera in my intake and they saw no oil. So i dunno where my oil loss is comming from if it isnt that.... But still if the computer is tuned to run at XX temp and you use a 180f therm wouldnt this cause it run in a open loop and burn more gasoline like if it were cold and running rich... I do use the same air filter setup you have but i dont see where a 180f thermostat would help as far as pinging goes or help on gas mileage.. The engine doesnt run that hot anyway according to a OBD reader it reachs about 213f at the sensor on the engine before the low speed fan kicks on and brings it down to 200f before shutting off.. Hense why the temp gague on a 5.9 always reads on the notc below the 210f mark... Using a 180f thermostat to me would seem to make it 15f cooler.. Specially if you use one of those switchs that activate at 195f vs 213f. Also as far running cooler and gas goes.. i tried running a cooler plug before and saw no help as far as pinging goes but i did see a drop in gas mileage.. Now using a 180f with a stock sensor doesnt seem like it would do anything as the fan would still come on at 213f..

The sensors all seem to activate at 195f.. Hense why i havent seen a replacement sensor for ours. I call a 18f activation temp a big diff.. Thats why i said ppl say it keeps the fan on 24/7 which isnt good for the fan motor.. Now that would seem good for the tranny if you wanna keep that cool lol.. but yea


As for pinging... my engine doesnt ping in the summer on hot days.. It pings in the winter which i find completetly oposite from what most people mention on this forum.. including you which i never understood.


Newfire as for what that thing is worth it me... Nothing right now because it seems all the switchs out there activate at a cooler temp then our stock ones keeping the fan on 24/7 so i dunno what im gonna do... Seems the only option is to swap the lower hose sensor to the upper one but if i cant get the thing out of the t fitting... I was kinda not wanting to remove the lower Tfitting and drain all my coolant..

Maybe I'll pay a visit to the salvage yard again.. The one about 40m away from me.. According to the 3-19-2013 list they have about 6 98 Grand cherokee's that are black/white so hopefully one will be a 5.9
"But still if the computer is tuned to run at XX temp and you use a 180f therm wouldnt this cause it run in a open loop and burn more gasoline like if it were cold and running rich.."
No, the engine still reaches full operating temperature. I live near Buffalo, NY, so the winters are COLD here. On the coldest winter day I still get plenty of heat.

"I do use the same air filter setup you have but i dont see where a 180f thermostat would help as far as pinging goes or help on gas mileage."
It just keeps the engine about 15 degrees cooler, especially in the hotest areas like the cylinder heads near the combustion chamber, than it would get with a 195 stat, but it still gets plenty hot believe me.

"Well, I do ping"
Have you tried different brands of gas? Do you use 91 or 93 octane? That does in some cases make a difference.

"the temp gague on a 5.9 always reads on the notc below the 210f mark
.."
The light hash mark just below the 210, or the darker one just below that one? Since new and before any mods mine always read about one needle width below the dark hash between 100 & 210. No sensor or thermostat change has ever changed that.

"my engine doesnt ping in the summer on hot days.. It pings in the winter"
Possibly the Charge temp sensor is sending a cold temp to the ECU which could cause a greater amount of ignition advance and trigger pinging. If there is a vacuum leak that could be the cause too. Even if the plenum isnt leaking oil, it might still have a vacuum leak if that leak is in just the right spot.

"Hense why i havent seen a replacement sensor for ours. "
Simple economics. There just are not enough 5.9 Limiteds for a company to make a profit getting a sensor certified for it. Remember the 5.9 electric fan was a one year anomoly and different from all other Chrysler systems. It costs a lot of money to get it certified as a direct replacement.

"Now that would seem good for the tranny if you wanna keep that cool lol"
Remember, the trans fluid can only get as cool as the temp of the water flowing through the radiator, and if you do something that super heats the trans fluid the radiator can not cool it fast enough to prevent damage, thats why auxilirary trans coolers are a good idea, especially on a Jeep because of the type of vehicle it is.

These are my own opinions arrived at through my experiences playing with my cars for 30+ years. Someone on this forum may very well have a better recommendation or solution than I, but my ideas seem to work in my cars. Good Luck
__________________
Jennifer
jenniferny is offline   Reply With Quote Quick reply to this message
Unread 03-23-2013, 06:19 AM   #13
newfieZJ
Registered User
1995 ZJ 
 
Join Date: May 2008
Location: , Alberta
Posts: 6,511
Quote:
Originally Posted by Candymancan View Post

Newfire as for what that thing is worth it me... Nothing right now because it seems all the switchs out there activate at a cooler temp then our stock ones keeping the fan on 24/7 so i dunno what im gonna do... Seems the only option is to swap the lower hose sensor to the upper one but if i cant get the thing out of the t fitting... I was kinda not wanting to remove the lower Tfitting and drain all my coolant..
I see no harm in the low fan kicking in early , or running all the time for that matter . Consider a 5.2 , that clutch fan always runs .

No prob on not wanting it . I like selling my spare parts about as much as having teeth pulled .

As for pinging , get that plenum done before you clog up your rings , eventually , it will happen as it did on my Orvis . I had 90 psi compression on 1 cyl and another just above resulting in my replacing that engine . At that point , even doing the plenum will not cure the ping , did nothing for mine at the time

With a tight plenum , you can run regular gas w/o pinging . My slate 5.9 has a perf PCM , my Orvis as a perf PCM and both do not ping if I cheap out on the gas . IMO , if it pings under any circumstance , you have an issue somewhere . My white one is flashed for regular gas . I do have a spare flashed PCM for regular gas and would trade it in a heartbeat for one that is not . Both my 5.9's were flashed when I bought them . My white one will get a tuner by summer which over writes the flash . I still run the higher octane because it burns less fuel and has more pep when I do .
newfieZJ is offline   Reply With Quote Quick reply to this message
Unread 03-23-2013, 07:12 AM   #14
coralman
I can wish can't I?
 
coralman's Avatar
1998 ZJ 
 
Join Date: Jul 2010
Location: florida
Posts: 4,804
I saw some radiator hose inserts that would accept sending units some where. If you still need one Candy I'll see if I can find it.
__________________
Links to axle rebuilds, mount replace,a/c box rebuild,ect in history section of my profile page
coralman is offline   Reply With Quote Quick reply to this message
Unread 03-23-2013, 09:46 AM   #15
5point9Limited
Registered User
1998 ZJ 
 
Join Date: Oct 2003
Location: South Jersey
Posts: 668
did you clean the fan motor? I took mine out and doused it with wd40, then blasted every opening with compressed air. a lot came out. my low speed fan now works beautifully.
__________________
Goodyear MT/R 245-75-16, Mopar PCM ECU, 52mm APS Throttle Body AND spacer, Flowmaster Exhaust, Homebrew K&N Intake, Summit 3" exhaust cutout, OME steering stabilizer, 2.25" B. Boost, ProComp MX-6 adjustable shocks,
Up-Country springs.
5point9Limited is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Thread Tools






Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.