AC and engine cuts off

ashyk36 · June 3, 2017

Hi all,

I own an IS250 (2010). A few weeks ago I was driving and the engine revs started going up and down vigorously.

The scenario is everytime I put the AC on, if at idle the engine will turn off after 10-15 seconds of the revs going up and down. If I am doing 30MPH and I turn the AC on the engine cuts of straight away.

Does anyone have any suggestions of what the issue could be?

Thanks in advance

peachy · June 3, 2017

Sounds like the AC pump is knackered.

There should be a connector on the ac pump which you can just unplug.
The other thing that really pulls my electrics down is the radiator fan kicking in when the ac is on (which usually only comes on when you are stationary).

Does your fan cut in? You'd hardly miss it as you will hear and feel it and all the lights on the car will dim.
I wonder if your fan is faulty and causing a short/drain.

The other thing I wonder about is whether your MAF is on the way out? If the maf signal is poor and reads erratically at low air flows then your idle may not be stable under load.

First port of call would be the ac pump I reckon. Disconnect the electrical connector and see if the problem goes away

Linas.P · June 3, 2017

Your AC pump has seized - happened to me last year. You need to replace/refurbish your A/C pump - quite costly job if using new parts.

Here is my thread from before (you can see in the video if that looks like your problem):

ashyk36 · June 4, 2017

Thanks both. Will have a look and report back

Hrky · June 5, 2017

One of my friend had a problem with what we call Micro-belt - belt thet connects aircondition compressor and car distribution. He had a lot of prblems because compressor jamed.

Best regards

Linas.P · June 5, 2017

In IS250 there is one single "accessories" belt, I don't think there are any other belts (obviously except timing chain). To summarise of my guess on the issue - the A/C pump seized and when A/C clutch tries to engage it the engine stalls. As my car was high miles one I guess my belt had some slack which allowed it to slip, whereas on @ashyk36 car it is tight and stalls the engine altogether.