Early this year I spent enough money with the dealer repairing the AC to buy another vehicle, literally. It was an ugly experience all around and essentially we're mutually done with each other. All new parts included compressor, condenser, dryer, AC lines, evaporator/heater core, expansion block, fan and whatever else makes an AC system do what it's supposed to do's been replaced. Air conditioning's been working flawlessly, like it was new, as it should, at least until about 2 months ago. This's an intermittent issue. Here's what happens, randomly the AC, even at max cooling (LO) will blow warm air. Doesn't matter if ambient temperature's in the 60s F or 90s F, it either blows cold or it blows warm. Some times it happens whilst driving but mostly it happens at a stop or idling. When it does happen, the compressor seems to cycle on and off about every 20-30 seconds AND each time it does, it shudders significantly.

For the record, intermittent blowing warm air was the original reason the AC repair was started last year, first by replacing what was determined a faulty compressor with a new compressor and the new compressor supposedly self destructed and destroyed every component in the AC system, hence the need for EVERYTHING to be replaced. Sometimes I think I can smell a faint burning rubber smell from the AC vent. Another point of interest which may or may not be related is since the repair, there is occasionally a loud screeching grinding noise from the front of the truck, sometimes when stopped, mostly AFTER everthing's been switched off. And finally, when blowing warm or hot air, I've noted ECT has climbed from 201-203 F to as high as 238 F and the cluster temp gauge also rises, though no warnings as of yet.

Without ANY real diagnosis, it's been suggested either it's leaking refrigerant OR the third new compressor's failing. A leak seems unlikely as it works flawlessly sometimes for as long as a week or more.

Thoughts?

 

The AC going hot when stopped or idling really sounds like your fan is not working properly. I was surprised to learn how quickly that problem can take your AC from cold to hot - like the time sitting at a red light. Could also account for higher coolant temps at idle. Could be the viscous clutch - many, many people have had to replace this, including myself. Could also be the wiring to the fan. It runs on pulse-width modulation, so there’s power and signal wiring.

As for the screeching/grinding at shutdown, that sounds like the ebrake module. It’s very strange, but I test drove a car that did this once. Sometimes when changing gears, and sometimes when turning it off, the ebrake would just start screeching and grinding - it sounded like it was coming from the front when inside the cabin. Finally, it just seized up. I don’t know why it was activating when shifting or turning the car on/off, but it was.

One other thing I remember reading - when the engine mounts start to go, the engine can shift enough that the fan can start rubbing the shroud.

Only other thing that comes to mind re: grinding would be the idler pulley - there is a tsb on this, but it describes it more as a moaning or humming sound - and the supercharger coupler, but that usually sounds like marbles.

 

Viscous fan was replaced less than a year ago and appears to be working correctly as it now spins at variable speed and no longer shakes as it's predecessor did. Engine mounts were replaced this year, accessory tensioner replaced and super charger was disassembled and pulley coupler checked, with which I saw no unexpected movement. AC worked perfectly yesterday, not working today though compressor's not cycling on and off nor inducing the violent shudder.

It has a new alternator, on it's third compressor, new accessory belt tensioner and water pump's about 2 years old now. That leaves steering pulley, supercharger tensioner (which appears to be in order), super charger (which also appears ok), crank pulley and fixed pulley between alternator and super charger tensioner.

The medium to low pitched grinding, squealing howl noise could definitely be the sound of brakes, though not certain how it could occur when the truck's completely stopped in either Neutral or Park or even immediately after switching off the engine as it does and if I didn't mention it, the sound occasionally repeats itself 2, 3 or even 4 times in a row. I rarely use the E-brake, only occasionally to keep it exercised. Also the noise had never occurred prior to the last AC repairs.

 

“compressor's not cycling on and off”

When you have the engine running, and not on auto climate control, you should be able to toggle on and off the AC switch in the console and the compressor should turn on and off. If it’s not doing that, then I guess the compressor might be going bad again. But something is wrong with three compressors going bad. The other possibility is that the compressor is shutting down because it’s overheating for some other reason.

“Viscous fan was replaced less than a year ago and appears to be working correctly as it now spins at variable speed and no longer shakes as it's predecessor did.”

I’m just wondering if it might not be going on when it is supposed to, i.e., when the AC compressor is running. Seems quite a coincidence that your AC is going hot and your engine is going hot. That fan is the only common component that I can think of. You should be able to see the fan duty cycle on your OBD software. You could check to see if it ramps up when the AC is turned on, and maybe check it the next time your ac is going hot.

“The medium to low pitched grinding, squealing howl noise could definitely be the sound of brakes, though not certain how it could occur when the truck's completely stopped in either Neutral or Park or even immediately after switching off the engine as it does and if I didn't mention it, the sound occasionally repeats itself 2, 3 or even 4 times in a row. I rarely use the E-brake, only occasionally to keep it exercised.”

So - this is the weird thing about the e-brake module: I don’t think it’s actually the brakes that make the horrible screeching noise. I think it might be the gears in the mechanism that pulls the cable. Not sure, but I know its not the movement of the brakes because, when it did it to me on this test vehicle, we were not moving. It was intermittent and happened when I put the car into gear, and then when putting it into park and (if I remember) once when we started the car. We were not using the ebrake at all. Very strange. But - if you can use the e-brake and it applies normally, then maybe not the problem. Wish I knew more about that system.

 

I'll monitor the e-brake.

As for the AC, It even sometimes happens at cold start, first thing in the morning in the cool garage, and takes a while to start blowing cold, but again not every time, sometimes it works perfectly. May not matter, but for the last 30 years, I've always had the habit of turning the AC off before turning off the vehicle to avoid additional coldstart load or at any other time and so I can hear and feel the AC come on when I manually turn it on after starting the vehicle. After the AC repairs were done, everything worked perfectly and smoothly and quietly and was freezing cold. That lasted for several months before this new problem started. I may be hyper sensitive trouble shooting this but it also seems as if the compressor's making a variable speed chugging noise and definitely coming from the left front wheel well. Also we're now with ambient temps in the 90s, where until now ambient temps were mostly in the 60s and 70s, occasionally getting into the 80s.

If it's the compressor for the third time and/or if it's the same problem it had a year ago then I don't know what to do. The main dealer insisted every component in the the ENTIRE climate system was replaced after this last go round and there's nothing left to have failed UNLESS it's one of the parts replaced earlier this year.

 

sounds to me like the compressor clutch. If the air gap is slightly too large, it can cause intermittent operation of the compressor.

 

These are clutch-less compressors though...they use a variable displacement swash plate. Could be coincidence, but the fact I am on the third compressor for essentially the same problem concerns me...

 

UPDATE.....

Since this hasn't been resolved I've more time to make observations.

Some cold starts the AC blows ice cold, some cold starts AC blows hot. Ambient temperature's not a factor as the truck could sit in the hot sun with temps over 100F and the AC starts up ice cold or hot, randomly. The "new" viscous fan appears to be operating correctly, sometimes slow, slow times super fast and roaring loud depending on engine temp, as it should but having no impact on whether AC is operating correctly. Sometimes AC will be hot whilst stopped and begin cooling when underway but sometimes it can still be hot even underway. Manually turning AC on and off still induces a momentary shudder from the engine. Not certain if this's conclusive but it seems if I switch from automatic gear selection to manual and maintain engine RPMs at around 3000 it will go from hot to cold. BUt again, some times it blows freezing cold at 600 RPMs just like it should.

I spoke with another main dealer and they have no ideas other than to start taking everything apart and no idea obviously of what it's going to cost. I've already spent nearly 10 grand early this year with another main dealer to repair the AC and I'm hesitant to start spending thousands more with no guarantee of where this's going to go.

I am so frustrated with Land Rover as to how multiple main dealers seem to be completely stumped by anything that goes wrong with these trucks. What's so mysterious about Land Rovers that even the manufacturer seems perplexed by their malfunctions?

 

About a month ago it finally stopped blowing cold air from the front AC, however the rear AC is perfectly cold. Took it to the main dealer and paid a diagnostics fee. They state the compressor is not pumping refrigerant and needs replacing. Went to another AC specialist and they believe since the rear AC works, it's an issue with the new front expansion valve.

Another observation I don't believe I previously mentioned when the AC's on, there's an intermittent metallic howl from the lower front right side, in the area of the compressor. If I turn off the AC, the howl goes away.

 

Went to the other non-Rover specialist today and they in fact determined a faulty front expansion valve. They also noted the viscous fan is not operating correctly and causing the air con system to overheat which in turn is causing the system multiple failures over the past year. This's interesting as prior to the original compressor failing at the end of 2021, the main dealer replaced the viscous fan (had I known it only takes 2 minutes to R&R I'd done it myself).