2003 Mazda Protege Overheating when AC is on

KMETZ2

MEMBER
2003 MAZDA PROTEGE
4 CYL
FWD
AUTOMATIC
98,000 MILES

I have a 2003 Mazda Protege with ~98,000 miles. I took a road trip from Louisiana up to Idaho this summer. On the outset of the road trip I recharged my AC myself, but over charged it by turning the can up-side-down. To solve this problem I bled off enough R-134a until the AC clutch would kick-on and stay on. The AC worked fine until somewhere in Missouri where it just went out. Eventually, my car overheated outside Denver, CO in the mountains. I took it to the shop and had the radiator and thermostat replaced, which coincidentally fixed my AC problem. From Colorado up to Idaho my AC and coolant systems worked fine, but coming down through Southern Utah and Arizona, I discovered my car would overheat whenever I had the AC on and was going up a hill (i.E. >4000 rpms and under 40 mph).

It would not overheat if the AC were off and I had high rpms with low traveling speed.

Any help would be great!

3 Replies

MHPAUTOS

MECHANIC
31,938 POSTS

HI there,

Thank you for the donation,

I would be checking that the condenser cooling fan is coming on with the A/C and that the engine fan is sill working as it should, start here and let me know your findings.

Mark (mhpautos)

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Tuesday, September 8th, 2009 AT 7:10 PM

KMETZ2

MEMBER
2 POSTS

I let my car heat up by idling it in the parking lot. While heating up and even once it was at normal operating temp no fan came on, but it did not overheat. I turned the ac on and one of the 2 electrical fans came on. Despite running the AC and sustaining rpm's of >4k while sitting in the parking lot, the car would not overheat and the temp gauge did not deviate from the norm, but the 2nd fan never came on.

Should both fans come on naturally, or will the 2nd only come on if it begins to get too hot? Would having too much pressure in the ac condenser cause it to over-heat? I notice when the condenser clutch kicks on the engine in REALLY taxed. If i'm running 4k rpm's and the clutch comes on it will drop almost 1000 rpm's.

Thanks

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Friday, September 11th, 2009 AT 12:32 PM

MHPAUTOS

MECHANIC
31,938 POSTS

Get the system pressures checked by an A/C tech, and have the engine cooling fan circuit checked as this should come on when the engine gets to just above normal operating temp.

Mark

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Friday, September 11th, 2009 AT 5:56 PM