Truck gets very warm with a/c on

[Duncanmac2807]

Hey guys, I'm new here I'm hoping someone can help me with this. I have a 1994 ford ranger 4wd 4.0L v6. My engine is almost to the red with the a/c kn and it makes me nervous. The truck stays at about 1/4-1/2 when it is off. I have replaced quiet a bit. I have replaced the thermostat, waterpump, radiator, fan and fan clutch, the system has been burped and flushed out. The coolant is very clean and there arent any coolant leaks anywhere. I do have a bad power steering pump bearing, I dont know if it would cause added stress but feel like I should mention it. The rest of the bearings on the vehicle seem good. The motor was rebuilt a couple of years ago, with about 33 thousand on the new motor. Hope someone can help, it's been over a hundred degrees here in salt lake the last day and stays in the 90s I'd really love to get it working.

 

[Dirtman]

Have you checked your fan clutch?

 

[Duncanmac2807]

yes, the fan clutch seems to be working as it should

 

[Ewgoetz]

Possibly the gauge sensor or the gauge is beginning to fail.
Is the fan shroud still there? Or damaged/modified in any way?
The thermostat may be sticking even though you replaced it.

I’d start with pulling out the thermostat and running it with out one, or boil water and drop your thermostat in it and see if it opens up all the way.
If it doesn’t get hot like you say than get a new thermostat.
Other option is replace the gauge sensor.

 

[Denisefwd93]

In that environment you probably should have an extreme Duty fan clutch. you should hear that fan when it's hot out, sound like a Jeep if you race the engine. if you don't hear the fan moving air something's not right.
air flow through the radiator and air conditioner condenser could be highly restricted even though it doesn't look dirty or clogged. I don't know if it's possible but could the thermostat be in backwards?

 

[rangerenthiusiast]

I like Ewgoetz’s suggestions. To be thorough, you might also want to check and see if you have any obstructions in the heater core, particularly if your heat in winter isn’t the greatest. Mineral buildup can cause those lines to really constrict internally, even if they’re not entirely closed. Just a thought.

 

[Denisefwd93]

Also to really know engine temperature you need a handheld infrared thermometer or a way of actually checking the coolant temperature. The dashboard gauge would be the least reliable way of knowing

 

[Duncanmac2807]

Hey thanks guys, I'll start by looking at the thermostat, maybe a heavier duty fan clutch. I'll get back to you, I'll be gone in our other vehicle for a week, ill get back to you then. Appreciate it thanks!