First problem: A/C cuts out while idling or moving slowly

[Wildewinds]

This is a bit long and kind of a rant.

So we first noticed it last summer while in Vegas. It was maybe 105 degrees and we were stuck in heavy traffic on the Strip. All of a sudden, the air conditioner stopped blowing cold air. It was as if the compressor stopped working and it was just blowing the hot air from outside. I tried turning it off and on again and it was no good. However, once there was a break in traffic and I accelerated, it kicked in and cold air started again.

After that, I noticed that it would happen intermitantly when the car was idling or in slow moving traffic. So, we took it in since we're still under warranty. The first time, the dealership in Pasadena had it for two days and they said they couldn't find anything wrong with it. They topped off the freon (or whatever they use these days) and told us to hope that was the problem.

Unfortunately, it would still cut off. We took it in again, they had it for almost four days, and they told us the same thing; they couldn't repeat the problem.

Here's where I started getting upset. I mean, so what if you couldn't repeat the problem? All that would tell them was that we weren't lying about the problem. It's not like they had a special sensor attached that would tell them what caused it (I asked, no special sensor). So I told them that was lame, and they said they couldn't do anything about it if they couldn't repeat the problem. I left, intent on returning with a better plan to get them to fix it.

So today it cut off no less than 10 times in 70 minutes of some crappy traffic. It seems to cut off whenever I'm not accelerating for a while. Once I hit the gas, it will start working again. It continues to blow, but you can feel the air get more humid and not cold any more.

All the times it cuts off, we have it set to the lowest temperature and on manual control.

Anybody ever have this problem or know what might be causing it? Any ideas on how to get the dealership to fix it?

 

[ryan-in-oregon]

I'm not positive but I think if the engine starts to get too warm the computer starts cutting non essentials to help keep it from over heating. (I believe I read this in the owners manual) Maybe your water pump is starting to go or the mix of coolant is wrong. Could also be a clogged radiator. These would be some good things to check.

 

[GMTIIFAN]

I've started experiencing the same problem over the last couple of weeks. It's been much warmer than normal so I've used the ac more and I have a similar problem. I haven't had it checked out, but what I am noticing is that my LR3 is idling lower (less than 1k rpm) when at a traffic light (stopped) and that is when it ac stops being cold. I can put in neutral and increase idle and it blows cold and as soon as I am moving again it's fine. I just thought perhaps it's low on freon, but not sure. I have an 05 SE7 with 56k miles. Please keep us posted.

 

[thorgal]

I haven't had it checked out, but what I am noticing is that my LR3 is idling lower (less than 1k rpm) when at a traffic light (stopped) and that is when it ac stops being cold..

LR3 normal idle is below 1k rpm anyway,I don't know what is yours , but it should be between 700-750 rpm, when warmed up,traffic light or not...

 

[tommithy]

Ryan-in-Oregon hit this on the head. The computer is most likely trying to keep the engine from overheating. The A/C condenser sits in front of the radiator so if the A/C is running it will preheat the already 105 degree air that you are pulling in so air that passes over the radiator itself is already hotter from just passing over the A/C condenser.

I see two options you could do here to help out.

When sitting at the red lights, drop it into neutral and rev the engine a bit.. maybe 1500 rpm or so.. enough to get the fan moving and pull more air through the radiator and A/C condenser.

The other option is some kind of aftermarket electric fan mounted in front of the truck to the A/C condenser. You could have this driven by a temp sensor and relay or just a switch on your dash that turns on the extra electric fan.

One thing you can check have checked is proper operation of the fan clutch that is on your engine fan. I'm not sure exactly how they test this but I'm pretty sure it's something that can be tested.

 

[ryan-in-oregon]

I wouldn't go adding any pieces to compensate for a problem. If it worked will up until this point you need to find and solve the problem. Maybe there is a layer of dirt dust in between the radiator and condensor that needs to be cleaned out? Not sure but this and the things I listed previously all need to be checked to find the problem.

 

[Wildewinds]

Anyone else ever had this problem?

 

[voltaire1102]

I started having the same problem a few days ago when the temp was in the low 100's. Just didn't cool off when the vehicle was dead still. Any of you guys ever figure out the problem?

 

[kingfishgrapeja]

Does the fan have a clutch that locks down on these to increase pull at idle. If so it likely is not doing it's job anymore. My audi's had a secondary electric fan that came on whenever the temp needed it or if the ac was running. When that fan would break you would lose ac at idle.

I haven't had reason to poke my head around in the LR3 so I am talking in guesses here.

 

[samterri]

Thanks, Wildewinds, for bringing this up. Just Thursday, I was looking a private owners 2006 LR3 to buy and when I cranked the car and let it idle for a bit, the air quit working. The owner said he didn't know about that, but it still raised a red flag for me. I called our local LR dealer and asked him about it and he said he had in fact seen this happen and said it was any of three things. The freon needed to be topped off, the fan needed to be replaced or the clutch to the fan needed to be replaced. Here in Norfolk, he said the most expensive the repair would be is $600. I'm sure prices vary nationwide. BTW, I bought the LR3, anyway. I couldn't pass on it. He was asking 19g's with around 50K miles. I pick it up in two weeks, so I'll let you know if the ac saga continues.