Air Conditioning

[BarryY]

Now we have had a bit of nice weather I put the air con on and the car all of a sudden seemed very sluggish, it was as if the ignition was being retarded every now and again. I would expect perhaps a bit of power loss when the air con is on but this was very noticeable. As I have only had the car for about 3 weeks I don't know if this is normal or not. When idling with air cond on the revs drop and hunt a little but this was at 70 on the road it was happening. Any thoughts anyone? Surely this cannot be normal.

 

[Anonymous]

It is normal to experience this with the Air-con turned on.

Based on engine idling:
When the compressor activates, it puts added load on the engine, so the revs dip. The ECU should then pull the revs up to compensate.
When the compressor de-activates, the extra load on the engine goes, so the revs rise. The ECU should then drop the revs back down to normal idle.
This should explain the 'hunting'.

You can feel this also when driving along.

To what 'extent' you will feel this, I really can't say. I have Air-con and I can notice it a lot when it's on.

 

[Ginger Tom]

It's normal, the compressor takes about 10-15% (iirc) of the engines power hence why it causes the engine to seem to hunt

 

[LOONEY]

and thats why it uses more fuel right?

 

[BarryY]

I would fully expect it to hunt on idle, but I have never experienced it like this before on any other car I have had when you are driving along, its difficult to explain, but it almost feels like the car is being held back. Sluggish and slow. I'm going to have a look to see if perhaps the belt is too tight, although it was serviced by Ford recently so in theory it should be ok.

 

[Ginger Tom]

@Looney, spot on mate

@BarryY, the belt won't be too tight as its got a self tensioning tensioner, couldn't think of another way of describing it, you could ask fords to service the aircon system, ie remove the refrigerant, clean it, replenish and top up if necessary, and top up the oil in the system. Other than that mate it is a feature of the model, my frp does the same

 

[Anonymous]

Maybe more noticeable when driving as you've got load on the engine to make the car move then the air-con comes on and puts even more load on it. So, when the air-con comes on, it would feel like the engine 'bogs down' for a short period.....

Same principle if you drive along and touch the brakes with your left foot while still holding the accelerator down. Then when you release the brake, the car surges forward..!?

 

[Ginger Tom]

Yeh or the clutch, I could bore you all with the technicalities of how the system works, but in essences it's got an electronically controlled clutch which is why it kicks in and out frequently

 

[BarryY]

Thanks for the info guys, I knew I would get a sensible answer on here.

I will live with it, but being a tight Scotsman I don't plan to use it much as it will put my fuel bill up!

Barry

 

[luke55]

Most cars are more stodgy and sluggish in hot weather, even without air-con.
I personally notice that more than the effect of the air-con.

It is probably more efficient to leave the air con on with recirc on than drive with a window open.

What I find strange is why the air-con suddenly feels cooler when the car slows to a stop.

 

[beko1987]

Mine nearly stalls when idling with the air con on, then picks itself back up sharply for another minute or so then nearly stalls again. Still, wouldn't live without it, and the sound of the fan at full scream feels good when sharply pulling up at work!

 

[melinamotor]

A normal trait of the Puma as stated, I also agree about every other car, the ones I have owned with the a/c you dont really notice a difference when driving. Its one of the things that has always annoyed me about the puma.

 

[BarryY]

I'm learning to live with it, although I think I have probably used it for the last time yesterday judging by our current weather forecast!

Have now had the car for about a month now and its still putting smiles on my face every time I drive it! Need to get some bits and bobs for it soon though, it needs rear bushes for definite. They will have to wait as my family bus (Espace) needs steering arms and a gaiter for the rack and an MOT this week.

 

[melinamotor]

I'm learning to live with it, although I think I have probably used it for the last time yesterday judging by our current weather forecast!

Have now had the car for about a month now and its still putting smiles on my face every time I drive it! Need to get some bits and bobs for it soon though, it needs rear bushes for definite. They will have to wait as my family bus (Espace) needs steering arms and a gaiter for the rack and an MOT this week.

Dont worry mate the sun is due to come back to our neck of the woods on Wednesday :wink:

 

[BarryY]

Perfect, just in time to go back to work!