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RPM drop when air-con is turn one

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Old 08-08-2006, 08:59 AM
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RPM drop when air-con is turn one

RPM drop when air-con is turn one, car vibrates at idle. when pull to D vibrates get worse, can see the RPM drop a bit. any idea why? if its not mounting.
Old 08-08-2006, 06:50 PM
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could it be the cat is block?
Old 08-08-2006, 07:10 PM
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let me guess, you didn't do a Search, did you?
Old 08-08-2006, 07:13 PM
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The way around it is to rev the car to redline. The reason being that the a/c is disabled at that point. Works well for me.
Old 08-08-2006, 07:15 PM
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It is normal for the engine rpm to drop when the A/C is activated. Do the RPM's come back up when you turn the A/C off ?
My A/C is always on ,so I don't notice the drop. If for some reason it has been off and
when I turn it on,, I feel the load of the compressor. And RPM drop.
It is normal for it to do this. Don't panic. If for some reason you think it is an issue ,take it to the dealer.
Old 08-08-2006, 07:31 PM
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so does this mean the vibration is not due to A/C ?
Old 08-08-2006, 07:31 PM
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did a search and couldn't find this
Old 08-08-2006, 07:43 PM
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Originally Posted by theboy
RPM drop when air-con is turn one, car vibrates at idle. when pull to D vibrates get worse, can see the RPM drop a bit. any idea why? if its not mounting.

It's fairly normal for rpm's to drop a little when AC is on or you put a load on the motor. Does it vibrate only when AC is on. You gotta AT right? I seem to recall some bad motor mounts causing vibration on AT's.
Old 08-08-2006, 08:04 PM
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It could be the engine or trans mounts. How many miles on the car?
They changed mine at 23,000 miles on our old RX-8 AT.
This was due to a noise/rattle coming from under the car.
They installed both engine mounts and a tranny mount. But I did not notice any strong vibrations or any unusual vibrations at idle for that matter.
Old 08-08-2006, 08:32 PM
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Check the thread called "Flash, new flash" or something like that. Very good information in there. If there is nothing mechanically wrong, you may find this info useful. Sounds like the update works nicely for this problem, and gives some other benefits too.
Old 08-08-2006, 08:37 PM
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The problem are the engine mounts , just changed them today and the vibration is gone, check them out there is a service bulletin for them.
Old 08-08-2006, 08:51 PM
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Nice!
Old 08-08-2006, 10:33 PM
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Originally Posted by Easy_E1
It could be the engine or trans mounts. How many miles on the car?
They changed mine at 23,000 miles on our old RX-8 AT.
This was due to a noise/rattle coming from under the car.
They installed both engine mounts and a tranny mount. But I did not notice any strong vibrations or any unusual vibrations at idle for that matter.
this is what i face i guess i hear rattle coming from the front under my car. must be it!
Old 08-08-2006, 10:34 PM
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any idea where i can get the Racing mounting by RIGID
or get the original one from mazda? mine is PI car.
Old 08-09-2006, 01:29 AM
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Get Mazda to replace the Engine Mount, they had some crappy material before and it will crack overtime.

after that, reflash your PCM to the newest one, if u'rs is a 04, it should be S, mine, a 05 looks like some F or something. 06 I dont know.

You're car should be fine as long as u do the above.
Old 08-09-2006, 07:25 AM
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Originally Posted by nycgps
Get Mazda to replace the Engine Mount, they had some crappy material before and it will crack overtime.
It's more than crappy materials, they were being destroyed by the engine heat. I think the newer ones have a heat shield.
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