Car losing power
 

My Rx loses power when Air Con On Gear changes erratic stalling at intersection making noises - loud clunk when taking off. Mazda say there is nothing wrong when sent for testing. Today even worse stalled three times gear changes all over the shop running rough and loud. What is wrong??? HELP

1. what year?
2. automatic or manual ?
3. do you speak english right?
4. how many miles?
5. when was the last time you replaced your coils/wires/and spark plugs?
6. have you had a compression done recently?
7. are you male or female?
8. do you have any aftermarket parts intalled in your vehicle?
9. it would be nice if you gave us more information on your vehicle.
10. are you in mexico?
11. if not press 1.
12. if you are in the USA press 2.

All cars lose power with the AC on, nothing you can do about that. You mention it making noises and a clunk, could you be hearing the AC clutch kick on and off? I don't really ever use my AC so I am not sure how loud this cars AC clutch may be.

What do you mean by "gear changes all over the shop".

Car losing power
 

2006 Auto Rx8 Female Australia Speaks English Regularly Serviced by Qualified Mechanic No Alterations No after market parts. Not sure about coils but Mazda say they have Cecked codes in PCM and TCM - updated PCM Checked Fuel Checked Engine mounts and connections to PCM Road tested to to reproduce concern - no fault found.
Engine losing power - I mean chugging/puff puff sound and then stalling when revs are down.
Gear changes become erratic from 2nd to 3rd and back to 2nd and 1st all at the same speed for instance 60km/hour.
This occurs when to Air Con is on and still continues when switched off.
Yesterday in the Yarra Valley in Australia it was 39 degrees Celcius - we use of our Air Cons in Australia!!!
If I start the car and drive without Air Con on the car runs beautifully - no issues.
I drove the car with Air Con on during the week and did not have issues.
Don't understand - could the Air Con need regassing?? Could it be a fault with Air Con upsetting sensors - really any ideas is all I'm asking for before I send it off again???
Thanks
Sue

For clunk, check engine mounts to see if one or both is broken.
For loss of power and stalling, replace all 4 spark plugs, wires, and ignition coils.
For weird shifting, check transmission fluid level.
Have a compression test done.

BC.

Everything Bladecutter said first. Then if still seeing issues with the car not holding revs steady at the 700-800 RPM level at idle with the air conditioning on (but it is OK with the air conditioning off), get the air conditioning compressor checked out. The compressor uses a magnetic clutch to engage/disengage when being turned on/off. Like all clutches, it wears out over time. Usually based on frequency of use. It is pretty easy to bench test, so any decent mechanic should be able to do it for you.

If the compressor clutch is having issues, you might wnat to look into a remanufactured compressor (versus a new one or having a mechanic rebuild the one on your car now).

THANKYOU!!! Now have something to go on rather than "No Fault Found"???
Cheers
Sue