rubbish heater

[jutwit]

my heater on my xj 2.5 petrol is only warm not hot even after 30 min of driving, could it need a new thermostat or is just how they are?

[scotty wong]

Its not how they are even the 2,5gets nice and warm.try the tstat but also google the yank sites for back flushing the heater core(matrix)

[scotty wong]

Its not how they are even the 2,5gets nice and warm.try the tstat but also google the yank sites for back flushing the heater core(matrix)

[( Gray )]

Could be that the heater matrix is blocked (re back flushing to clear out, as above), or it could have (amongst other things) an airlock in it.

[CHEROKEECH]

Totally agree with the above post, Mine was exactly the same until I flushed it through now its spot on, I used 2 lengths of hose pipe, 1 attached to my outside tap then to 1 of the matrix pipes under the bonnet, and the 2nd from the other matrix pipe and into a drain (or a bucket), then I slowly turned on the tap and slowly built up the pressure until the water flowed clear.
Had to do it again after a year or so but I was running mine on almost pure radweld at one point to get home from France

[john1961]

ive flushed the entire cooling system out refilled with new antifreeze/water mix ,no air locks or restrictions through the heater matrix checked the function of heater controls all ok .....heater still crap running at 90 c on gauge any ideas ??? might take water pump off n av a look at that ??? although it doesn't overheat ?????

[jonny jeep]

When the engines at running temp and the heater on, compare the heat from the hoses going into and out of the heater. If the hoses are both hot and about the same temp then the coolant is flowing freely through the heater core and maybe the blend door isn't shutting off the cold air flow fully. If you have one hot hose and one much cooler the heater core is restricted.

[scotty wong]

Hows the viscos fan working? Not cooling to much?