Sup everyone, so it's almost March, but here in San Diego the weather in February has warmed up already. Before I had my 105k service done(timing belt kit, water pump and radiator) back in October, my car would mildly creep up in temperature in the summertime while I was using the AC. Usually through the 100-110F ambient temp days. The last few years have seen some crazy high temps. So when I got my service done I decided to throw in a Mishimoto aluminum rad and had new OEM T-stat and hoses, with the Subaru super blue coolant. I haven't tested it out full on yet, but last week saw some 90F ambient and I've used the AC. It never overheated. Note both my radiator fans do work... Any other opinion to cause a mild temperature rise while the AC is running? Thanks guys!
Hot weather and Air Conditioning
- Thread starter JeySTI_
- Start date
HolyCrapItsFast
Drinks beer!
The AC will effect the rate at which the temperature rises but it shouldn't go much past it's normal range. How hot is it getting? The temperature should really never go much past 212*f. If it does then that means one of two things. The cooling system is still not adequate enough to keep up with the demand or there is another mechanical issue like sticky thermostat, head gasket issues, blockage and more.
You said you had a service recently where they replaced the timing belt. Did this condition exist before that or after? Bad valve timing can make your temps soar as well.
You said you had a service recently where they replaced the timing belt. Did this condition exist before that or after? Bad valve timing can make your temps soar as well.
Oh this was BEFORE I had the timing belt service done back in October. In September we were heat waving in SoCal temps as high as 110F, probably about every other day for a week. So one day I decided to use the AC, and this was on the highway going about 70-80mph. The stock temp needle crept a little, not past the upper 2nd notch mark. I've read that anywhere between the first and 2nd notch mark is "NORMAL OPERATION", but geez, that 2nd notch mark is not that far from the very top end mark. I wouldn't assume it's my head gasket going... I haven't see any oil mixture with coolant, and I'm holding a good constant engine temp on the gauge needle. So as of today I was out with the family and it was about 70F outside, obviously that's not that warm. Had the AC on low for the wife and kid. Temps were fine, but I'm just curious why back in the heat wave when I was using my AC, my temp was going up a bit. I was kind of thinking the AC condensor had something to do with it? I don't know, I'm not an A/C specialist, but that thing is in the way of our radiators... and it's out there for heated air exchange...
Oh another thing to note, I had the AC recharged at a local AC shop almost a year ago, they even put this "dye" or something to check for leaks in case something tends to happened. And so back to that day just before my temps crept up, the AC was blowing WARM AIR for about 10seconds before the needle moved. There wasn't any cooling system leaks because I was cooling the car down after my drive when I got to work that day, and I opened the hood, and nope, no leaks. Another thing, it was about 85-90F outside at midnite when I got off, so I decided to brave the issue and blasted the AC on low again... Miraculously the temp never rose up like it did 9 hours before that, and it was blowing some nice cold air. So I would have no idea what went on with that overheating issue. It bugs me because I carry my infant daughter in the back of that car on some summer days and need to blast the AC for her. Luckily I didn't overheat on days I had her with me
Last edited:
Yes it was from the AC, because as soon as I saw the temp needle creep up and rise, I turned off the AC, and the temps lowered back to the normal driving range, where it sits just above the first notch mark. And yes, nothing has happened since the Mishimoto rad was put in. Since November-January it's remained cool out here in SoCal. But Spring is approaching and we are getting ready to see early Summer temps kicking in. So I'm hoping this won't be an issue.
