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Put ZJ fan clutch in my XJ. Always roars. Question?

J

JeeperYJ

NAXJA Forum User
Location
Ventura
I put a Hayden 2737 ZJ fan clutch on my XJ. It roars all the time. I never hear it quiet down. Can someone post up that has done the swap. Is yours the same? The temps outside are cool where I am. If this is normal I am fine with it. I like how it keep the Jeep cool.

If I rev it at idle, I never hear the fan quiet down as the RPM's increase. Also, on freeway, same. Loud roar.
 
lol... my friend just did the exact same thing and text me "this thing roars".. just about everyone says the same thing, but are happy w/the extra cooling. i'll prob swap mine too.
 
Ok. I was going to exchange it. But, if its normal. Then I am ok with it. The a/c is colder, temps this past summer remained less than 210* when it was 115* outside. Very happy. It's a toy for us, so we only drive it for offroad or something. But, the wife and I took it out today, and it was cool outside, and it was roaring on freeway. I stomped on it, sounded like it wanted to stop being loud, and tried, but didn't. lol.
 
JeeperYJ said:
I put a Hayden 2737 ZJ fan clutch on my XJ. It roars all the time. I never hear it quiet down. Can someone post up that has done the swap. Is yours the same? The temps outside are cool where I am. If this is normal I am fine with it. I like how it keep the Jeep cool.
If I rev it at idle, I never hear the fan quiet down as the RPM's increase. Also, on freeway, same. Loud roar.
Click to expand...

It will roar year round, even on cold winter days, where it will delay warmup or keep the engine from coming up to its normal operating temperature.
It will also knock an MPG or two off your freeway cruising mileage.
I ran ran one for a several months before giving up on it, not being one of the better mods. If yours is a trail only rig and you live where there are very hot summers, it might be a good idea but it isn't a good one for a DD IMO.
To me, it's a crummy band-aid for a not up to snuff cooling system. It's better to figure out why the stock cooling system isn't working correctly.
 
Thanks for the feedback. The cooling system was replaced. I just didn't like it running at 210-215*. Now it runs at 185-195*. A/c is cooler, etc.

But, yes. It roars day or night. Little loss in power. Acts a little goofy under WOT like the fan tries to unlock but doesn't.

127746d1341172821-put-zj-clutch-fan-xj-keep-cooler-worked-photos-cluster.jpg
 
Last edited:
lazyxj said:
It will roar year round, even on cold winter days, where it will delay warmup or keep the engine from coming up to its normal operating temperature.
It will also knock an MPG or two off your freeway cruising mileage.
I ran ran one for a several months before giving up on it, not being one of the better mods. If yours is a trail only rig and you live where there are very hot summers, it might be a good idea but it isn't a good one for a DD IMO.
To me, it's a crummy band-aid for a not up to snuff cooling system. It's better to figure out why the stock cooling system isn't working correctly.
Click to expand...

Agreed w/this ... I ran one on my XJ this past Summer for about 1 month... killed my mileage by about 40 miles per tank... NOT a good investment for my DD. Thought it might help w/the amount of city driving I do and traffic idling, but hood vents worked better in my application (2001 XJ).

Put a new OE unit back on and won't go back the HD clutch.
 
JeeperYJ said:
Thanks for the feedback. The cooling system was replaced. I just didn't like it running at. Now it runs at 185-195*. A/C is cooler, etc.
But, yes. It roars day or night. Little loss in power. Acts a little goofy under WOT like the fan tries to unlock but doesn't.
127746d1341172821-put-zj-clutch-fan-xj-keep-cooler-worked-photos-cluster.jpg
Click to expand...

You do realize that your XJ was Factory designed to run at 210-215*, the temperature the computer wants to see. The 195 degree thermostat is set to start opening at 195 and to be fully open at around 210.
Running cool is not doing your engine any good, just wait until this winter when you get out to the mountains or desert and the temps are really cold, you will be wishing for more heat.
Very cold weather shouldn't be too much of problem in Ventura, with its mild temps, I took my sea kayak out of there yesterday, up the coast about 8 miles, what a beautiful day!
 
lazyxj said:
You do realize that your XJ was Factory designed to run at 210-215*, the temperature the computer wants to see. The 195 degree thermostat is set to start opening at 195 and to be fully open at around 210.
Running cool is not doing your engine any good, just wait until this winter when you get out to the mountains or desert and the temps are really cold, you will be wishing for more heat.
Very cold weather shouldn't be too much of problem in Ventura, with its mild temps, I took my sea kayak out of there yesterday, up the coast about 8 miles, what a beautiful day!
Click to expand...

With the 180* stat in CA. There is no issue on the heater (keep us warm when needed). It's also not a DD. I put maybe 3,000 a year on it. It's a toy for us.

I had same setup on YJ for 3yrs (don't remember the fan roaring as much though). Ran trails in summer and winter. Never a problem for us. Thanks for the concerns.

Redsnake said:
Agreed w/this ... I ran one on my XJ this past Summer for about 1 month... killed my mileage by about 40 miles per tank... NOT a good investment for my DD. Thought it might help w/the amount of city driving I do and traffic idling, but hood vents worked better in my application (2001 XJ).

Put a new OE unit back on and won't go back the HD clutch.
Click to expand...

What temps are you running now with hood vents? What hood vents are you running?
 
Last edited:
JeeperYJ said:
With the 180* stat in CA. There is no issue on the heater (keep us warm when needed). It's also not a DD. I put maybe 3,000 a year on it. It's a toy for us.

I had same setup on YJ for 3yrs (don't remember the fan roaring as much though). Ran trails in summer and winter. Never a problem for us. Thanks for the concerns.



What temps are you running now with hood vents? What hood vents are you running?
Click to expand...

Here's a thread w/my hood vents and info... they are working out quite nicely now that I have the drip pan added...

http://www.naxja.org/forum/showthread.php?t=1085714

Temps when it was 100+ Degrees outside would register around the middle of my OE guage.... perhaps just a bit more when sitting idling in the sun. So I'm guessing around 210-215... but I would not get the vapor lock or hard start-ups after parking and letting the XJ sit for ~ 5-10 minutes and then trying to restart. Now that the outside temps are down... it runs cooler, say ~ 200-205. Nice and cool... :)
 
i installed the 272310 fan clutch (ZJ fan clutch from napa) and i must be hard of hearing or just not bothered by this roaring that everyone proclaims about LOL because I dont hear it
 
it's the fan that is noisy, not the clutch. if you don't hear a difference, something isnt working right. i've seen new fan clutches from napa with zero holding force after about a week so that wouldnt be a suprise if it were bad.

i'm about ready to ditch mine, the noise is getting old.
 
The roaring is caused by the fan blade pitch.

Fanclutches and their percentage of engine revs engagement is normally matched to a suitable blade pitch.

A little bit of digging around tech info shows that the stock fan pitch is not, best suited, to the factory original, light duty fanclutch ... nor the heavier duty one.



lazyxj said:
You do realize that your XJ was Factory designed to run at 210-215*, the temperature the computer wants to see. The 195 degree thermostat is set to start opening at 195 and to be fully open at around 210.
Running cool is not doing your engine any good, just wait until this winter when you get out to the mountains or desert and the temps are really cold, you will be wishing for more heat.
Very cold weather shouldn't be too much of problem in Ventura, with its mild temps, I took my sea kayak out of there yesterday, up the coast about 8 miles, what a beautiful day!
Click to expand...


Digging around in a little bit more tech info will reveal ....

- that the minimum "warmed cycle" ... that the XJ's PCM is looking for - is about 160*,
- 195* t'stats start to open slightly before 195* and most brands will be open before 210.
- despite the mythology that the world will end ... if an XJ doesnt have a 195* t'stat ... a 180* t'stat option was offered by the factory ...


.... and never reveal that the vehicle was designed to run at 215 for engineering purposes.

The info might reveal that higher running temps are a bandaid fix by car companies to meet govt imposed emission regulations tho.


190* - 200* running temp ... and you will have a very happy XJ.
 
carves said:
- despite the mythology that the world will end ... if an XJ doesnt have a 195* t'stat ... a 180* t'stat option was offered by the factory ...
.... and never reveal that the vehicle was designed to run at 215 for engineering purposes.
The info might reveal that higher running temps are a bandaid fix by car companies to meet govt imposed emission regulations tho.
190* - 200* running temp ... and you will have a very happy XJ.
Click to expand...

Interesting, would you have any links to this information, I have never run into it while searching through Factory and aftermarket literature.
Most 4.0s live a long, happy life running a 195 degree thermostat.
 
lazyxj said:
Interesting, would you have any links to this information, I have never run into it while searching through Factory and aftermarket literature.
Most 4.0s live a long, happy life running a 195 degree thermostat.
Click to expand...

For the years i have been trolling this forum, I see hundreds of posts dictating that the 4.0L must run above 210 degrees for it to run properly. This have not been my experience since I bought my first XJ in 2000. Running down the highway at high way speeds inthe winter in Iowa or summer in South Florida, the temperature guage usually read below the 210 mark,...I would assume about 200 degrees. Now I have a Scanguage in the XJ, it actually reads between 195 and 200 degrees. Below highway speed and stop and go traffic it could get up to 215 degrees before the dual electric fans come on and pull the temperature back down. The few times the guage stand straight up to the 210 line is an indication that the cooling system need servicing. And yes, I am using the OEM/Chrysler issue thermostat.

Also, I am in agreement with LazyXJ. There is no reliable information about the 4.0L ever uses a 180 dergee thermostat. To the contrary, my CD based manual said quite clearly, ' All engines uses a 195 degree thermostat'. I looked it up :read: so as to dissagree with LazyXJ.

LazyXJ, choose another topic so I could dissagree with you. :cheers:
 
I threw the HD fan clutch on my XJ when I was having overheating problems. Helped a bit.

In march, I had the cooling system replaced (water pump, hoses, t-stat ... no rad as it was already replaced). We had a cold snap and afterwards, I couldn't get it past 190. Still cant.

http://www.youtube.com/watch?v=IuwKIV3O6eo&feature=plcp - I don't think I went above 2500!


I ABSOLUTELY LOVE the sound of it. In our local club, that's how everyone knows I'm bombing through the mud. It probably did damage my gas mileage a bit, but I rarely drive it more than a few miles - it's a spare vehicle.

I do like it for it's cooling. This summer, a group of about 5 XJs went in a group on a decent trail. I was the only one that didn't overheat and have to pop the hood. Out of our group of 5, 4 of them were 2000s ... guess who had the only 2000 to start without sputtering. I can sit on the trail on a hot day with my A/C on and wheel the hell out of the jeep and NOT go above 215 - same with the A/C on in a traffic jam.

I'm thinking about ditching it for the winter and grabbing a stock junkyard fan, and using that for the winter.
 
I used to run one as well. Used to being the key words. Swapped it in during the summer to help (100+ degree days and lots of humidity makes for an unhappy Jeep when crawling up mountain trails), then swap in the stock one for the winter months. After the Crawl this summer, I wasn't happy with the plastic radaitor's cooling performance and swapped in a 3 core CSF, which made a very nice difference in performance. Matter of fact, first cool morning this month with the ZJ clutch in I had a hard time keeping it at or above 190...kept wanting to run cool. That's when I decided to swap in the stock clutch for good. Sits dead on 210 right now, MAYBE 215 if I sit in traffic for a while.

Plus, if you're running the same 3 core radiator and try to run a ZJ clutch, you'll have the same issues I did. It'll fit, but it involves much swearing and quite a few bloody knuckles...
 
I love the roar...
and mine never goes above 206deg, usually 195 to 198 even on a Hot South Carolina Summer day with or without the A/C on.
Rock solid.
 
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