heater matrix

[4560max]

hi my heater would only blow cold air on the drivers side but worked o/k on the passenger side .the garage fitted a new heater matrix under warranty.the new one blew cold air on face but now only hot air on feet,by now the garage were pulling there hair out they have never heard of it happening before,that then tried a new heater modem ? it now seems to be working o/k fingers crossed,has anyone else had this problem ??? thanks 4560max

[J44EAG]

Max,

typically, this can happen on the S-type due electrical heater tap failure. As the X350 and S are so closely related in so many aspects, I wonder if this is the root cause of your problem.

You don`t say if your car is dealer, independent Jaguar operator or local Joe maintained. It would probably take the dealer or independent to know about this classic fault.

If you find the heater valve which is possibly down at the front of the engine, have someone work the heater controls. if the valve is working, you may hear the motor noise. That is a rough guide but you would be best to take the car to a knowledgeable maintainer of Jags, if you are not already doing so.

This is not my best bit of advice ever, but it might point you in the right direction.

Mike Kennedy

[4560max]

thanks mike for the reply .i use a jag dealer and after a lot of testing found that i had to have a new matrix and also a new modem it now works fine thanking you 4560max

[I_MNL]

And how much for the privilege, if I may ask?

[J44EAG]

Nearly six years after the last post posed the question of matrix replacement costs, I can answer that. (06/01/2018)

The cost of a new OE twin core heater matrix is £119.39 retail plus VAT. Currently on back order, supplies from Jaguar will become available by about mid January 2018. The part number is C2C7071. This matrix although in one unit has two cores. One section provides air to the front passenger cabin area whilst the other provides heated air to the drivers area. A individual temperature function is therefore afforded to the driver and passenger.

So what are the common problems with the X350/358 climate control and the matrix in particular?

Firstly, the heater control module/resistor (C2C39577) can burn out. Replacement cost retail is £143.09 plus VAT. This unit controls the speed of the blower motor and various other functions. Burn out should be suspected if the touch screen unit and temperature display functions up and down in apparent temperature but the blower motor stops working. Expect a labour cost for around two hours if replacement is needed.

On V8 models, heater/coolant is pumped around the heater matrix by an electric auxiliary heater pump. This is a small Hella made pump which is located directly under the header tank on the off side directly behind the radiator pack and off side main beam headlight. The cost is around £166. This pump becomes rather unreliable after around 100k miles on the road. You will need to reach deep down behind the radiator pack to access the pump. Two typical spring hose clips hold the flow and return rubber hoses to stub pipes on the pump. Long hose clip pliers will help grab and hold the hose clips which need to be slid off the hoses before the hoses can be removed from the pump. An electrical feed connector is fitted to the bottom of the pump. The pump runs consistently if the cabin heater function is switched on from the running position of the ignition switch. If replacing this pump, do not confuse with the similar looking inter-cooler circulation pump fitted to the front of the radiator pack on supercharged models. Check the function of the pump before condemning a heater matrix. The pump can be heard or felt running if still functioning.

The heater matrix removal/replacement is booked as a three hour job if it requires replacement through blockage. New pipe seals should be fitted to a new matrix. Access to the complete mechanical heater unit and the heater control module/resistor pack appears to be via the passenger foot-well and glove box.

No heat out of either driver or passenger air outlets implies both cores are blocked or the auxiliary electric heater pump has failed. Heat from just one side of the matrix implies a total blockage in one core of the matrix. Reduced heat on one side implies a partial core blockage. Reduced heat on both sides implies a partial blockage on both cores of the matrix.

Surrey Jag Centre gave me an estimate for supplying and fitting a new matrix of around £350.

Decisions, decisions. What to do? I have a partial matrix blockage on the drivers side which really affects my in car comfort when outside ambient temperatures fall below zero. Its not pleasant and spoils the car. I have two bottles of rad flush sat next to my tooth brush. It helps focus my mind...The under-tray is off my 350R and its too cold to mess about putting it back on at this time of year. This gives the opportunity to access the radiator drain cock which I believe is on the nearside of the rad. If I can find the thing, it would seem I could drop the coolant into my Mothers best washing up bowl whilst she is up at Sainsburys. With header tank in place and ignition switched on to fire the auxiliary heater pump and the inter-cooler pump, I could capture the bulk of coolant for re-use and flush out the remains with the hose and refill with fresh water and the rad flush. With luck, whilst I still have partial flow on the heater matrix, I may be able to clear the blockage. The engine and inter-cooler rads would also get a flush to boot. Any disadvantages? Perhaps....radiators and heater matrix full of pin holes and leaks! I think this is worth a try with the £8 rad flush treatment before I just hand over £350 for work that may not be necessary.

More once I find the radiator tap and the weather is a bit warmer.

Mike