MGFord

Nitehawkjr gives a very through explanation, the only thing I would like to add is, when your removing the core access panel use a ratchet and long a extension. Work your ratchet from outside the glove box. This makes it a lot easier.

smart88

I have leaking underneath the heater core area. If I add about a pint of water to the radiator daily (I average 20 miles driving a day), the engine stays cool. Water is not leaking inside the truck. Just for your knowledge before I ask my questions. The truck normally runs with the needle about 1/8" into the NORMAL bracket. When it gets slightly low on water she runs around the "N". My friend borrowed my truck today and drove her 100 miles with the needle reaching the "OR" area, apparently not paying attention to my instructions that she is hot if the needle stays in the center and give her water long before she gets to that spot. He said I need to replace the heater core and radiator and the temp guage needle will probably then be in the center for normal driving. So, question 1. Do you find all vehicles have their own normal spot or should the needle be in the center of the guage? Question 2, since I am replacing the heater core, dumping radiator fluids etc. Should I replace the radiator or spend money on flushing and maybe find out the radiator should be replaced anyway? The radiator has rusty water and not a lot of evidence of coolent. I think the previous owner was neglectful. What symtoms if any, are evident that make radiator replacement necessary other than leaking?

Just call me Sean

iTrader: (1)

The needle can be anywhere, for instance mine is always below "N" unless it is hot, it's when it gets hot that it moves off your normal spot. Change the core and run it, if the radiator isn't leaking you don't need it.

broncojunkie

While you're in there, replace the thermostat as well. If you've got rust in the system, chances are the thermostat is toast. Rust will eat them up in a hurry. Your engine needs to run at the correct temperature. Too hot, and you'll blow a gasket or crack or warp something. Too cool, and it ain't gonna run right. Some people think it's ok to remove the thermostat instead of fixing the overheating problem. You could get away with it on older vehicles (although you wouldn't have much heat when it got cold). Newer engines monitor the temperature and adjust the fuel mixture in response. Too cool, and it thinks it is still try to reach normal operating temp.

Just call me Sean

iTrader: (1)

Yes if it got hot change the thermostat too. With a good one, not the cheapest one the store has.

smart88

I will plan on flushing the radiator and replacing the heater core. I'll do the thermostat also. What about the sensors for heat temp. I don't know the proper name, should they be replaced. I read something like an ECM sensor? Sorry, I didn't write it down when I was checking out other threads.
Autozone has a heater core in stock. Will their quality be fine or do I look for a big name brand?

I drove the truck tonight and before I could get to the gas station about 1/2 mile away the temp was above HER normal. I put quite a bit of water in her and the temp came right down. I drove 10 miles and the temp never got into the normal bracket. She drove smooth and sounded fine so I am hoping no damage was done by my friend's drive.

smart88

The thermostat has been changed and the truck is running normal temp. again.

Now, I'm at the beginning of the heater core replacement having removed the glovebox, ABS control module and 6 screws around the panel. (Wow, I sound like I know what I'm doing!) BUT I cannot release the white thing at the top, I think it's called the damper cable retainer. So I am stopped until one of you guys tells me how to move it.

Just call me Sean

iTrader: (1)

Take a pic because I have no idea what you're talking about.

smart88

This is not mine but similar. It's the white thing holding a cable at the top left.