Hi all,

I’ve got a 2012 L322 5.0 Supercharged and I’m having an issue with the heating.

If I drive the car until the temperature gauge reaches the middle and then turn the heater on, it blows cold. If I keep the revs low, the temperature gauge drops down to the blue, and the heater starts blowing warm. As soon as I speed up again, the gauge goes back to the middle and the heater turns cold.

I’ve replaced the thermostat and coolant cap with genuine Land Rover parts, this seemed to steady the coolant gauge fluctuation a bit, but that didn’t make any difference to the actual heat.

At idle, the heater blows warm air, but as soon as I start driving, it goes cold again.

I’ve bled the coolant system several times, but it hasn’t made a difference.

Anyone come across this before or have any suggestions? Seems to blow hot at low revs but not at high revs, and only when the temp gauge is reading lower than normal.

Other than the heater issue the car doesn’t overheat and I’ve driven long trips on it and the heater performance is the same.

Thanks.

Most likley the common issue of the heater control valve

https://ebay.us/m/cszdul

Here is a cheap one on the bay try getting a good brand or genius even better.

Hi, thanks for that.

Why would this affect the heat at different engine speeds though?

If I just bypassed the valve and put a Y-piece in, will this mean the heat is on all the time even if I set the heater controls to cold?

You cannot by pass it for that very reason it's the control valve. Different engine speeds effect the coolant flow......that's what I experienced when mine went faulty.

Okay thanks I’ll look into changing it then and hope that solves the problem.

If it was winter I’d bypass it as a temporary solution to rule anything else out but better not this time of year

Gates EHV133 is the OEM part. Don’t bother with cheapo copies from the online auctioneer - ask me how I know - the Gates part isn’t much more expensive and is considerably better (original) quality.

If you remove the airbox, you have better access to the pipes from the front. Not a difficult job, just a pain to get to. -------------------------
2012 4.4 TDV8 Vogue
2001 Audi A2 1.4 16V
2019 Skoda Kodiaq (don't ask...)

The gates one looks different to mine, I think that maybe for the FBH. Mines a 2 solenoid one looks the same as the above eBay link.

Mines a petrol so guessing they didn’t need the FBH as it warms up pretty quickly. Just not the cabin

I’ve changed the heater control valve, but the old ones were all broken up, so they needed replacing.

However, the heater performance is still poor. The passenger side blows warm most of the time, and the driver’s side will occasionally. The engine temperature gauge will drop to blue with the heaters on, even at low fan speed. Additionally, the heater can still blow cold when the engine is at normal running temperature.

I’ve already changed the engine thermostat because I thought the old one was stuck open.

Does anyone have any ideas what else could be causing this issue?

Also, it’s a 5.0 supercharged petrol, so I don’t think it has the FBH. .

As you have now proved it was the control valve and it was all broken up and have poor heating 1 side of the car compared to the other it proberly means those broken up bits are blocking the heater matrix.
Try reverse flushing it to clear it out I had yo flush our d3 matrix to restore heat on passenger side.

I flushed out the heater matrix when I did it to make sure there was no blockages.

My concern is why doesn’t he temperature gauge keep going down when the heatings used surely this should stay in the middle while I’m driving?

Yeah temp gauge should stay in yhe middle I suspect an air lock.

Also try switching the flow and return over at the heater matrix to see if the heating changes sides. Have you confirmed the aux pump is working ?