I just noticed this symptom this morning. When the car is idling (or when I'm not stepping on the accelerator) with aircond on, the car shakes very badly and the engine feels like it could die anytime. When I turned it off, the engine feels normal again.

I parked my car and put it to P and tried turning the AC off and on several times and observed this:
AC on - car shakes badly.
AC off - car doesn't shake.

My friend told me his car had this symptom before his compressor died in a spectacular show of white smoke.

So could the compressor be the culprit? Please help!

Edit: Oh my car is a 10-year-old 1.5L auto Wira.

This post has been edited by Aurora Boreali: May 27 2010, 10:02 AM

Inspect the engine mounting, probably cracked and have to change. This will cause the car to shake badly. Also, you will need to get the air regulator thingie serviced. Probably clogged with carbon or dust. Usually they will wash it with diesel/petrol.

if only shakes when ac on, it sounds like wiring / battery problem...

to sum it up: when the ac also gets power from alternator / battery, there is not enough power to provide sufficient spark to your spark plugs, hence the shake.

or maybe the spark plugs are so worn out, even sufficient power will not produce a good spark.

possible solutions: change spark plugs, check wiring, add voltage stabilizer, add grounding, etc...

last time.. my kelisa also liek that...

the mechanic told me i hav 2 prob... thermostat and my fuel injection (throttle body) is not betul anymore... i didnt repair... i sell the kelisa and buy saga... 10 yrs old also..

This post has been edited by omara86: May 27 2010, 10:22 AM

more like certain vacumm hose crack

mounting - not necessary coz that's not the cause of the shaking...
air cond unit - not big effect... my previous case, i did refurbish my aircond system (compressor, piping, filter, bla bla) still no improvement for my shaking prob.

my case is hav sumthing to do with throttle body timing/firing...

Hm, the problem here is:

AC on - car shakes badly.
AC off - car doesn't shake.

Maybe I should send it to the workshop... but I don't want the mechanics to slaughter my wallet!

when this happened??... all the while got this problem or jz this morning??..

if its fuel injection, check the ISC socket at the back of ur throttle body... mayb loosen adi.... if ISC socket loosen adi, ur ISC gears wont work to bring the idling rpm up when load (aircond, power steering, etc.) is on...

if its carburetor, check the vacuum hose connected to the ficd and idle load compensator (the thing dat looks like an ufo).... disconnected vacuum hose wont activate the actuator to bring the idle rpm up...

aircond compressor gets power via belts connected to the pulley of ur engine...
sparkplugs worn out will affect the engine regardless aircond switched on/off...

install toyota FICD.
my wira have same problem too. after installed FICD, u can control air flow into engine manually. RPM wont drop anymore!

I gotta agree with omara86. Your symptoms sounds like a problem with the throttle body. Normally, the car would automatically push the RPM higher when under load from the air cond. Right now, your car doesn't seem to be doing that anymore, so it is no longer able to maintain a high enough RPM while idling with the air cond switched ON, therefore the engine is borderline about die, causing the vibration. You will notice when you are driving and not idle, the vibration goes away.

My wira 1.5 also got the same problem. Went to mech and was told the plastic gears in the throttle body broken. Changed to local spare plastic gear but problem still there. Mech told me that the local plastic gear may not be good quality and asked me to replace the throttle body which cost > RM 1000.

Of course I don't have enough money and my car is still having this problem. Any advice ?

wah... ur mechanic chop 9 u ahh??... sparepart shop selling rm1xx only... with labour charge max also rm300 laa....

Really ? How much it costed you and where did you installed it ?

that FICD cost arround rm60 only, u can fit it urself ler..

FICD ? whats is that

yo! i have old proton saga around 6-7 years old also have this problem exactly as <+Newbie+ > said...so how much will it cost to repair it? any shop recommended around subang and kelana jaya here? and what should i tell the mech? pretty scare that they will chop me lol. newbie for my car, juz got it from my bro...

thanks in advance...

Tell us more what is FICD, what does it stand for and how does it work to increase the idle speed of the engine?

Is it being used to decrease the stoichiometric ratio or increase the amount of airfuel mixture electrically?

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Added on July 26, 2010, 7:05 pmCar shake? Not engine shake?

This post has been edited by J1@l_ l_l l\l: Jul 26 2010, 07:05 PM

fast idle control device
its basically an adjustable actuator where it allows an amount of air leaked into the engine to increase the engine rpm, when the aircond kicks in
only works for fuel injection engine as ecu compensates the bypassed air with fuel, hence increasing the engine rpm

no it is not used to increase or decrease the air fuel ratio... it is not a piggyback ecu

Compressor problem you either get no air cond or air cond with hot air (magnetic coil) so it has to be something else.