jodaso2

lately my 95' 4runner 3.0l V6 has been overheating I am hoping it is something as simple as the readiator. A friend of mine told me that if the air:fuel ratios are not right this can cause it to over heat. Is this true :cry:

jodaso2

sorry I went something as simple as the thermostat

admiral

Air to fuel ratio causing over heating? I would do a cooling system flush first and see if that helps, and maybe check the fan clutch and the A/C fan if they are not working properly. I know it gets hot in El Paso.

jodaso2

A/c fan comes on, it overheated with the a/c off in the morning, how do I check the fan clutch.

admiral

This is of an article from Popular mechanics

Check for slop in the clutch. With the engine off and the fan stopped, try to rock the fan blade fore-aft to feel for free play in the clutch. Don't confuse this with flex in the blade. If the fan moves half an inch or more, something's wrong inside the clutch.

You also can check fan speed with a photo-tachometer, an inexpensive tester that is used when a conventional tach can't easily be employed. The photo-tach uses an infrared beam, aimed at a strip of tape, usually attached to the edge of a spinning fan blade. It's worth using if the manufacturer provides any specs, even approximate. On some late-model Jeep Grand Cherokees that have both a special clutch fan and a separate electric fan, the factory spec is just 300 rpm max with the engine cold. Here, the electric fan is a major contributor to engine cooling. On other systems, with a cool engine, you'll find fan speed at about 1250 to 1500 rpm when the engine is revving at 3000 rpm. At high coolant temperatures, the fan speed will rise to about 2100 to 2500 rpm with the engine revving at 3000 rpm.

admiral

To check if the thermostat is opening, warm up the engine to operating temperature, than squeeze the hose that goes from the engine to the radiator, the one on top, there should be water in there. Hope this helps troubleshoot your problem on your 4runner.

jodaso2

thanks for the help I will try it out. One more Question I flushed the system when I change the thermostat on saturday. It took 1 1/4 gal. of antifreeze (hoy fox toyota told me to use green here in el paso) now it has no antifreeze and there is no leak. I checked to make sure water didn't mix with oil, it didn't where's the antifreeze? I sure the heck don't know.

LittleRedToyota

did you burp the cooling system?

if not, you probably had air trapped in the cooling system when you filled it. after running the engine for awhile, the air made its way to the radiator and the coolant replaced it elsewhere in the system.

either park on an incline with the front of the truck up the hill or just jack up the front of the truck. set the heater control to full on (full heat).

with the engine cold, take off the radiator cap and fill the radiator to near the top with coolant. leaving the cap *off*, start the truck and let it warm up to normal operating temperature.

if there is any more air trapped in the system, it will work its way to the radiator and burp out. if that happens and the coolant level drops, re-fill the radiator. once it has stopped burping out air for awhile, turn off the truck and put the radiator cap back on. make sure you have adequate coolant in the overflow tank. if not, add some.

keep an eye on the level of the coolant in the overflow tank for a few days. if there is anymore air in the system, it will end up in the tank and coolant from the tank will be drawn into the cooling system (and, thus, need to be replaced).

also, here's some more info on the fan clutch:

http://www.off-road.com/~estegall/te...fanclutch.html

http://www.barneymc.com/toy_root/techneek/fan_clch.htm

jodaso2

thanks to all u guys have been truly helpful.