If the temp outside is maybe 80 degrees or hotter and I turn my a/c on, within a few miles of stop and go driving the engine temp start to climb past 195 degrees on the temp gauge. It never went past the 3/4 mark, however when I parked the car and let it sit overnight then went to drive it the next day I noticed that it was running hotter than usual again and this was with the a/c off. I checked the coolant and the reservoir was almost empty, so I refilled and have been trying to avois using the a/c.
What would cause the engine to run hotter than usual and blow coolant out through the reservoir when using the a/c ? This has never happened any other time except for when using the a/c on hot days. I recharged the a/c system not too long ago with EZ Chill r-134a that has a stop leak additive. Could this be the problem ?
Also, I have noticed a wierd humming/rubbing sound from the compressor/pulley area when driving with the a/c on.The noise is especially apparent when accelerating from about 1000 rpm to 3000 rpm. Could a worn serpentine belt be slipping under load and cause the engine to run hotter ? This is a 99 z24 ld9 auto. I also should not that this car has an aftermarket hayden cooling fan instead of the factory fan and I always keep it on whenever the a/c is on.
Maybe your thermostat is sticking. Is your coolant mixed correctly? Also coolant usually only comes out the overflow when it is boiling meaning above 230*. I would check your coolant, tstat, and fan. If they are ok then there is another issue. Only other one that comes to mind is a failing head gasket pressurizing the coolant. If you take the cap off and let the car idle you would see bubles or smoke coming from the coolant.
On the inside my car looks like a fighter jet.
maybe your fan isn't kicking on properly...I swapped my radiator fan motor out ($25 part at a parts store) and it fixed it. Though mine had 190k miles at the time and it was hitting the red line and going all the way off the temp gauge...texas heat + traffic = death to engines without coolant flowing!
04 Cav. 2dr. 5spd. My DD. 'Nuff said.
Was a 50/50 mix of water and dexcool, but it's pushed coolant through the overflow twice now and both times I only added water so now it probably 60/40 or 70/30. It only does this if I use the A/C on a hot day. I have a hayden aftermarket cooling fan wired to a toggle switch and most the time I never even have to turn it on unless I'm in slow moving traffic.
I always turn it on if I turn the a/c on, but on hot days it just doesn't cool. It has a new water pump and I've replaced the thermosat twice thinking that it might solve the problem to no avail. Specific gravity test for coolant checks out as well. Could being off a tooth on cam timing either exhaust or intake or both cause this ? My cam timing might be off a little, but if it is it's not much because the engine runs great and gets about 20 mpg city and 29-30 highway. It does have a ticking noise below 1000 rpm after the engine has warmed up. Also, the black plastic thing that directs airflow from the bumper to the radiator is missing. At least I guess that's what it supposed to be there for.
Dexcool should be a different mix i belive, maybe a clogged line, rad, core or even air in the system somewere.
Fireboy153
Brady Fire Co. - Station 150
Long Live The Sunflower! (yea its not so "cool")
I'd flush your system thoroughly and use regular antifreeze instead of dexcool. Even if that it isn't the problem, it couldn't hurt
I've bled the system via disconnecting the upper coolant line that runs above the exhaust manifold. In the owners manual and on the coolant reservoir it says to use dexcool only. Dexcool has certain specific corrosion inhibitors, etc... for these engines. Using anything other than dexcool can be harmful in the long run, or is GM just sayingf that ? I'm sure the engineers who desgined and built these vehicles know what they're doing and don't just tell us to use dexcool for no reason.
The same reason they tell you to rotate your tires every 3000 miles (every oil change) or flush your power steering fluid even when it's not dirty. They will tell you a lot of stuff in order to make an extra few bucks.
Did you ever find what was wrong? I might be having the same problem?
