Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: somersetsid on November 18, 2012, 10:41:46 PM

Title: Getting hot but not overheating
Post by: somersetsid on November 18, 2012, 10:41:46 PM
Hi All, I think I may be starting to get a problem with my jeeps cooling system, (1996 xj 4.0) I fitted a new water pump some months ago and all has been well untill this week, Whilst driving back from Weymouth this evening the engine water temp was going up to around 110 and then droppping back to 90 before sitting at 100 for a few min before repeating the up and down, the air temp was a cool 6dg and I was in clear traffic doing about 50 mph, I am not using any water or oil and cant see any leaks or blockages on the rad, also whilst sat at traffic lights the temp went up to 130/140 and the elec fan came on but the temp did not drop back untill we started to move again, If any one has any idea what might be causing this I would be most greatful as I like to nip this one in the bud before it fails big time.

Just to add, I have had no loss of power or missfires
Title: Re: Getting hot but not overheating
Post by: Cockney Boy on November 18, 2012, 10:51:48 PM
When you changed the pump did you change the thermostat
Title: Re: Getting hot but not overheating
Post by: gazjeep on November 18, 2012, 10:53:36 PM
 :iagree:
Title: Re: Getting hot but not overheating
Post by: demonicwillow on November 19, 2012, 12:11:51 AM
Also possible that its a viscous fan related, the eleccy fan is there to assist the main fan but if the viscous coupling isnt working properly the lectric fan may struggle, it may have leaked its oil or the front of it is kegged up.
Title: Re: Getting hot but not overheating
Post by: Ric Jacques on November 19, 2012, 03:22:25 AM
Does sound like a thermostat issue...........
Title: Re: Getting hot but not overheating
Post by: Bubba on November 19, 2012, 03:33:42 PM
i would go for stat 
Title: Re: Getting hot but not overheating
Post by: somersetsid on November 19, 2012, 04:46:45 PM
Hi All, many thanks for your replys and advice, I did not fit a new stat when I replaced the water pump so I have ordered a new one today and will keep you posted on how it goes once fitted, many thanks again,
Title: Re: Getting hot but not overheating
Post by: Dave69 on December 02, 2012, 03:48:23 PM
the new pump will create a flow vs cooling effect where the cooling will not be stable. mine used to fluctuate between 90 and 100 constantly and that was after pump and thermostat change. on the go-jeep site there is advice on adding a flow restrictor to the top hose which creates an even coolant pressure
Title: Re: Getting hot but not overheating
Post by: somersetsid on December 02, 2012, 03:54:42 PM
Many thanks for all your replys, since i fitted the new thermostat a week ago all has been fine with the temp staying nice and stable.

Many thanks again