khoney

I made an interesting observation today while I spent two hours trying duplicate the power loss problem I had twice this week.

I could make the A/C compressor cycle on and off by stomping on the throttle while in neutral, even if only for a quarter-second. The RPMs would not even go above 3K, but the compressor A/C clutch would engage/disengage like this:

1) Stomp on throttle for a split second
2) Clutch disengages almost immediately
3) Clutch re-engages at around 2-3K, because my foot is off the throttle.
4) Clutch disengages at around 1250RPM
5) RPMs do a slight jump, then clutch reengages

I could make this happen every single time I blipped the throttle. I wonder if this happens when I'm in stop-and-go traffic at rush hour, like the kind of traffic where you move forward one car length and stop. All that repeated A/C compressor cycling can't possibly be good for the car. Could this create additional heat in the engine, causing my eventual power-loss problem?

I know one of the flashes had a feature where the A/C would cut off under hard accel, but this was in neutral.

BTW, I only started noticing it after the engine had gotten very hot, and my ambient display was about 107.

StealthTL

iTrader: (1)

The a/c cut-out isn't on "hard acceleration", it is on 70% throttle pedal sensor.(IIR)

So even if the throttle body never even moves, the a/c will cut out just from pedal position.

S

Brice-RX8

This is so you have more passing power with wide open throttle (WOT). If you want to stay cool, then don't press the pedal to the floor, if you want to fly at WOT then you are going to have little cool air until you release the pedal some.

khoney

I understand why they did what they did. What I'm really wondering is if there are other driving situations other than WOT which could result in 70% pedal position? The reason I'm asking this is I'm trying to track down an intermittent power loss problem, and I'm looking for any possible the reason the engine might overheat.

Brice-RX8

Do you have power loss with the A/C completely off?

khoney

No, It has always happened with A/C on, because it has always been about 100 degrees out. This is a very intermittent problem - my car has lost power and made the rattling marbles sound about 3 times now. It has died on me in traffic twice. One of those times, it would not start until I let it sit for an hour or so.

I am unable to reproduce this problem for the dealership, so they said they will do nothing at all for me.

Brice-RX8

Ok, the car is fine with no A/C, but with the A/C on it overheats or has too much load on it. If you aren't running premium gas, then I would say that your car is requiring you to have it, if you are then that isn't a problem. The only other thing I can suggest is to have the dealership update the flash (recall flash is the latest) or let them keep it till they see the problem for themselves.

RotaMotion

My A/C hates me--> car idling in traffic, MT, a quick blip of the throttle no more than 30% will trip the A/C clutch and turn off the compressor for a few seconds.

khoney

That's exactly what I'm talking about. Something like that would happen a lot if you're creeping along in traffic at rush hour.

Glyphon

https://www.rx8club.com/showpost.php...92&postcount=7

khoney

My A/C already behaves as described.

Glyphon

ok. going back to the power loss problem, do you have a MT or AT?

khoney

Mt.

RotaMotion

Mine already does that too.

RodsterinFL

Ahh, I have had 3 compressors fail and I believe it is directly related to the clutch and the RPMs. The first compressor failed at highway speed. We were traveling uptown on the expressway and the AC was cycling. All of the sudden it cycled on and it started ticking like a playing card in a bicycle's wheels. The paperwork read, " clutch bearing failure/ compressor failure. This happened 2 more times not due to highway driving (rarely use the highway) but stop and go. I have a manual 6 spd.

davefzr

This happened to me as well.. I just recently got the R flash.. I may take it in soon to see what the issue is. I hear the ticking noise and also a strange noise coming from the A/C when I step on the gas pedal. Nice to know it's not just me that is experiencing this.

GrayRx810k

I have sort of the same problem. My 04 rx8 is a 4 speed auto (I know ). I have no loss in power from the ac issue but my ac does cycle like crazy. On then 10 seconds and then off 5 sec then same thing over and over again, while driving and stops. I was build 09/03 and im out of warranty at 62000 miles. I recently visited my stelership for a check engine light, but my car has no problems and I also let them know about the ac, they said they had problems reading "the computer" and It needed to be replaced at 1300 dollars. I need help here and am offering a 30 dollar reward thru paypal for anyone that can solve my problem.

swoope

iTrader: (5)

answered in your other thread.

beers