Calgary Jeep Association

4x4 Related Groups => Tech Talk => Topic started by: giorno71 on July 30, 2009, 08:56:05 PM

Title: overheating
Post by: giorno71 on July 30, 2009, 08:56:05 PM
Just put a 4.0 l in my yj now it keeps overheating. do i have to upgrsde the rad. it's curently the stock from the 2.5. the water pump workes fine and i changed the thermostat.
Title: Re: overheating
Post by: Whips17 on July 30, 2009, 09:06:02 PM
When I upgraded my motor I had to up grade my rad from a 2 core to a 4 core and it made a big diff,  also a electic fan will also make a big diff not only in cooling but thotle responce also.
Title: Re: overheating
Post by: giorno71 on July 30, 2009, 10:15:00 PM
ya i have 2 eletric fans one pusher and one puller
Title: Re: overheating
Post by: JackstandJohnny on July 30, 2009, 10:24:54 PM
is the 4.0L good?  blown headgasket may cause that......
Title: Re: overheating
Post by: giorno71 on July 30, 2009, 10:34:42 PM
Took it out of a 92 xj  took the xj from medicine hat to calgary and back and temp never went over 100 about a 3 hour drive each way, now i cant make it 5 min out of town and have to pull over and let it cool down
Title: Re: overheating
Post by: dunl on July 30, 2009, 10:41:31 PM
Air bubble?
Title: Re: overheating
Post by: giorno71 on July 30, 2009, 10:44:27 PM
Dont think so  flushed the system twice and new antifreeze. even changed the temp sender
Title: Re: overheating
Post by: JackstandJohnny on July 30, 2009, 10:47:19 PM
thats weird dude. mine is running a stock 2.5L rad and its nice and cool.  what size tires?  stock XJ, big YJ?  isn't running a pusher/puller setup counter productive?  (i am unsure of this)

maybe the rad is no good?
Title: Re: overheating
Post by: giorno71 on July 30, 2009, 10:50:53 PM
running 31X 10.50 tires and my 2.5 never had a problem with it and if i disconnect the pusher fan the temp goes up faster. i havent presure tested the rad but i tried the garden hose in the top port to see if i had lots of flow through it and it came out almost as fast as it went in
Title: Re: overheating
Post by: JENSSEN on July 31, 2009, 08:17:00 AM
Check your fuel pressure

Lean = HOT!
Title: Re: overheating
Post by: slimbeam on July 31, 2009, 08:26:21 AM
some water pumps are forward rotating  (2.5 + 4.2L with "V" drive belts) the 4.2L + 4.L and 2.5L with serpentine belt is reverse rotating.  you may  have the wrong pump for your setup
Title: Re: overheating
Post by: giorno71 on August 01, 2009, 12:30:33 AM
i have a infared temp gun to... but thanks . the water pump on the motor was on it when i did the swaped and it worked fine in the xj. changed the rad cap this evening will test it tommorow. also someone told me you can use clr to disolive corosion in the rad... has anyone tried this? seems kinda sketcy to me but the last thing i wanna do is buy a new rad and that not b the problem.
Title: Re: overheating
Post by: barmanjay on August 01, 2009, 11:20:45 AM
The t-stat is installed the right way?
Title: Re: overheating
Post by: giorno71 on August 01, 2009, 06:44:44 PM
yep   it is  double checked that
Title: Re: overheating
Post by: BlackYJ on August 04, 2009, 07:18:50 AM
The rads are the same between the 2.5 L and 4.0L.

Is the rad clogged with mud?  Do you have a winch blocking the rad?
Title: Re: overheating
Post by: giorno71 on August 04, 2009, 06:32:01 PM
the rad is totaly clear of mud and debre and i do have a winch but have never had the problem wth the winch before.
Title: Re: overheating
Post by: BlackYJ on August 04, 2009, 09:16:29 PM
I had the same problem when I swapped my 4.0L in.  It ran great for 2 summers and then started getting pretty warm.  This spring I just swapped in a heavy duty rad and it runs great
Title: Re: overheating
Post by: Evil-Jeep on August 05, 2009, 10:15:59 AM
A bit of a longshot here...... are you actually overheating or are you just going by the gauge? It could be a bad  sensor or a bad reading between the sensor and the computer. If you are running in the red I would think you should atleast see a little fluid in the overflow.
Title: Re: overheating
Post by: giorno71 on August 05, 2009, 06:32:02 PM
yep was going by the gauge then swaped it out...same thing... but yes it is over heating the coolent in the overflow looked like it was boiling... front end gets very hot and the firewall and floor at the shifter radiates a lot of heat