Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: Bubba on November 19, 2010, 05:08:01 PM

Title: heater /aircon a bit strange
Post by: Bubba on November 19, 2010, 05:08:01 PM

mk1 xj  as the heater on the floater is not overly warm i suspected an air lock so took the top return pipe off at the bulkhead to find almost no flow at tickover that rises as the revs rise     so i now suspect that there may be no thermostat in the engine as generaly the flow is aided by thermostat being in place forcing the water to bypass the partial restriction


i also noticed the aircon pump cycling evan though the aircon was not selected as heater was in the heat position  .....any idea why ????

i also noticed the electric fan cycling evan though the temp was not at working temp well below 100...any ideas...??


till i get a new stat i pulled the aircon relay and disconnected leky fan  but it did make me wonder why the heater is better now but not fab

so as know almost nothing of xjs i hand the question to the hoards of xj folk out there

Title: Re: heater /aircon a bit strange
Post by: Mike Pavelin on November 19, 2010, 05:15:44 PM

The A/C come on and fan will cycle if the heater is set to demist, in order to dehumidify the air.

Title: Re: heater /aircon a bit strange
Post by: Bulldog67 on November 19, 2010, 05:17:44 PM

its karma punishin u for gettin all fancy wiv ya jeeps, just create a doz or so drafts thru the bodywork and all will return to normal

Title: Re: heater /aircon a bit strange
Post by: JamesH on November 19, 2010, 05:39:54 PM

On mine there are only 2 vent settings that don't use the aircon - I suspect you have it set on one that does use the aircon - as Mike described

Title: Re: heater /aircon a bit strange
Post by: Panic mechanic! on November 19, 2010, 05:47:10 PM

bubba +cj7/cj8= god
bubba +xj       = potato

 :017:

Title: Re: heater /aircon a bit strange
Post by: Bubba on November 19, 2010, 06:17:07 PM

very true i will not pretend to be an axpert on such things

Title: Re: heater /aircon a bit strange
Post by: donk498 on November 19, 2010, 08:16:14 PM

If its on the windscreen position the air con is on. As for the heater what temp is showing on the engine gauge, i had dodgy stat (bleed valve missing) and that made the heater crap.

Title: Re: heater /aircon a bit strange
Post by: Panic mechanic! on November 19, 2010, 08:23:09 PM

In all honesty the best heater I have seen in a xj was a diesel..... it was really toasty warm til the headgasket went otherwise they  have not been the best of heaters.

Title: Re: heater /aircon a bit strange
Post by: big g on November 19, 2010, 08:53:49 PM

Try backflushin' the matrix.

Mine was pants 'til I did that.

Title: Re: heater /aircon a bit strange
Post by: Dave69 on November 19, 2010, 09:40:57 PM

does the aircon actually work and blow cold, if not then it could be low refigerant as this was the case on mine and the air con fan was constantly cycling.

heat on the 4ltr blows hot after 10 mins but the diesel heater was crap in winter full stop and took ages to get the same level of heat