Air Conditioner and Overheating - Toyota Nation Forum : Toyota Car and Truck Forums

Killinchy · 09-26-2002, 12:54 PM

Twice now my 93 Camry Sport has overheated after a few hours hard driving (it's "hilly" in BC). Fortunately, after a short wait, I've restarted the car and the temp guage has dropped back to normal very quickly.

My questions are these: why does AC cause overheating? - isn't it just another small pump that's working. And why doesn't Toyota (and the rest) make a cooling system that can handle the demands of AC?

Thanks

John Owen

PLRBEAR · 09-26-2002, 03:42 PM

Might want to check your thermostat. If it's busted, then it won't open up to allow coolant to run through the engine block. Chances are, that's what's causing the overheating.

A/C puts quite a load on the engine, thus the engine works harder to run the compressor, hence the extra heat.

91camryDX · 09-26-2002, 10:20 PM

When you see your temperature gauge start to rise, turn on your heater, as it sucks away some hot air from the engine.

PLRBEAR · 09-26-2002, 10:31 PM

Quote:

Originally Posted by 91camryDX

When you see your temperature gauge start to rise, turn on your heater, as it sucks away some hot air from the engine.

That would qualify as a good short-term solution. :wink:

2dcamrystick · 09-27-2002, 02:23 AM

if its overheatimng take it to the dealership and fix it. pay as much as it takes. it will be worth it. overheating may be a very seriouse problem

PLRBEAR · 09-27-2002, 10:28 AM

another possibilty is that your car's coolant system may need a flush. If it hasn't been changed in over a year, perhaps it's time to do it anyway. In any case, if you're planning to change the thermostat, you might as well do a coolant flush while you're at it. New coolant with a 50/50 mix should suffice.

Other things that can cause overheating:

1)Late timing
2)Plugged radiator
3)Faulty fan
4)Collapsing bottom radiator hose
5)Low oil level

I'd check the oil level, bottom radiator hose, see if the fan's working and do the thermostat and radiator maintenance first before trying anything else, since they're really inexpensive fixes.

Killinchy · 09-27-2002, 02:37 PM

Thanks, guys. I'll check the rad for dead animals. What I can't understand is why the engine suddenly overheats after hours of driving, and why the temp drops back to normal so quickly. I've put in two new thermostats and a new water pump (and got a flush).

John

PLRBEAR · 09-27-2002, 04:18 PM

And it still overheats??
How about the temperature sender (sensor?). when you say hard driving...what exactly does that mean? rpms?
Check the radiator to see if it's really fudged, although i don't think damaged cooling fins can cause something like that really.
I'm assuming you haven't added any water to the radiator since the flush? Really, i don't think it's the way the car's been built. We have Camrys back home that run in city traffic (red light every 100-150metres), idle like nuts and operate in 27-33degC (high 70s to mid 80F) temps and they don't overheat. Air-conditioning is a way of life back in Singapore too!

Killinchy · 09-28-2002, 03:03 PM

Thanks, PLRBEAR

"Hard driving"? I mean from Vancouver up to the top of the Coquahalla Hiway (5000? feet) on a hot day, then driving for a hour along the top. The car overheated just before I descended into the Okanagan Valley.

At least I know now that not everyone's Camry overheats - I'll figure it out

John

PLRBEAR · 09-28-2002, 03:12 PM

No problem. I'm helping you out as much as i can because i'd be so flustered if i were in your situation. I won't be able to sleep soundly knowing that there's some unresolved issue with my car.