Aircon on Idle drop

[jarod]

My manual Mazda 323 have been incurring erratic idling and I turned to have it tuned-up and all. The idling went better but I still manage to observe times where the idling dropped too much to have the car shake a lot.

I happen to notice that this only happens when I'm in traffic, whether night or day. I realized that the only difference between my everyday driving and when in traffic is that my condenser is not properly ventilated. I thought that since the condenser is getting hot, freon might not be circulating well making the compressor work hard and making it harder to rotate. When that happens the engine would then have a sudden additional load thus experiencing sudden idle drops :roll:

These could probably be cause by clogged condenser or unbalanced freon charge?

Are my assumptions making sense?

[scharnhorst]

Sir, baka yung idle-up mo may problema

[jarod]

Sir, baka yung idle-up mo may problema

Thanks scharnhorst but the idle-up is ok since the idle works ok even if I've been idle for a minute. The problem only starts when I have been stucked in traffic. When coming to a stop or running, I assume that my condenser is ventilated because the car is moving or moving previously. I just thought that in traffic, there is no wind to cool down my condenser.

I'm still not sure about the condesnser though but I'm sure that all engine components were double checked for any issues.

[scharnhorst]

If standstill ventilation yung problema, baka pwede ka magpa fit ng auxiliary fan para dun sa condenser

Let's wait for other opinions...

[bambino]

malalaman yan sa manifold gauge readings kung may malfunction sa A/C SYSTEMS kaya get it checked by a qualified AC TECH first.

[ruelsdcz]

check your condenser aux fan.

[jick.cejoco]

My manual Mazda 323 have been incurring erratic idling and I turned to have it tuned-up and all. The idling went better but I still manage to observe times where the idling dropped too much to have the car shake a lot.

I happen to notice that this only happens when I'm in traffic, whether night or day. I realized that the only difference between my everyday driving and when in traffic is that my condenser is not properly ventilated. I thought that since the condenser is getting hot, freon might not be circulating well making the compressor work hard and making it harder to rotate. When that happens the engine would then have a sudden additional load thus experiencing sudden idle drops :roll:

These could probably be cause by clogged condenser or unbalanced freon charge?

Are my assumptions making sense?

jarod,
the symptoms you described fits the description of high head pressure. this is an abnormally high pressure originating from the compressor discharge port to the receiver/drier, to the condenser and behind the expansion valve. high pressure develops if the receiver/drier is saturated with moisture as in the system had been serviced without replacing the receiver/drier. if you are still using freon (R-12), your suction side around 32-37 p.s.i. and your discharge side should be around 260-280 p.s.i. depending on ambient temperature and humidity. your system might have been overcharged. today's climate control systems only use a fraction of the airconditioners of yesteryears. hence, the modern climate controls are more sensitive to even 1/5 of an ounce of extra refrigerant. if your system is using R 134a, your suction side should read around 27 p.s.i. and the discharge side should be around 260-290 p.s.i. again depending on the ambient temperature and humidity. have youre system serviced and your receiver/drier replaced and you should be fine.
jick

[jarod]

malalaman yan sa manifold gauge readings kung may malfunction sa A/C SYSTEMS kaya get it checked by a qualified AC TECH first.

Very well noted sir. I do hope we have shops that do that here or would that be just a simple reading instrument that most shops would have? Sorry if I might sound to ridicule the shops in here, it's just that I am not familiar the the gauge reading instruments sound high-tech to me

check your condenser aux fan.

I checked it last night and it's doing fine. I thought at first that it could be at fault but when i checked it again, it went doing fine.

jarod,
the symptoms you described fits the description of high head pressure. this is an abnormally high pressure originating from the compressor discharge port to the receiver/drier, to the condenser and behind the expansion valve. high pressure develops if the receiver/drier is saturated with moisture as in the system had been serviced without replacing the receiver/drier. if you are still using freon (R-12), your suction side around 32-37 p.s.i. and your discharge side should be around 260-280 p.s.i. depending on ambient temperature and humidity. your system might have been overcharged. today's climate control systems only use a fraction of the airconditioners of yesteryears. hence, the modern climate controls are more sensitive to even 1/5 of an ounce of extra refrigerant. if your system is using R 134a, your suction side should read around 27 p.s.i. and the discharge side should be around 260-290 p.s.i. again depending on the ambient temperature and humidity. have youre system serviced and your receiver/drier replaced and you should be fine.
jick

It is already using R134a and the first owner haven't had it cleaned yet since 1998 upto now that I bought it. I'm just kind of paranoid that other problems would occur if I have it cleaned without knowing first if it is really needed to be cleaned because it is actually performing well except during traffic. Nevertheless, your suggestion is very well noted and I now understand more on how it behaves, would have it checked then soon.


Guys, also I happen to notice that most of the time when the compressor engages, I hear a rattling or boiling sound (sorry it's hard to describe it) when I'm in the cabin. Unfortunately, I was not able to pop the hood to identify where it comes from. Would that be the compressor or just the refrigerant? Is my system in urgency for a check-up?