my 94 Ranger is overheating a lot and I need help troubleshooting.

[Dragonfrootz]

So to begin, I am useless when it comes to mechanics. But I do know how to keep my truck running. So in October I had a really bad overheat, and my truck was steaming. Well I flushed the radiator the next day, put fresh coolant into it and I called it good. (The coolant in there while I was flushing it was rusty and brown and chunky.) And I’ve checked it every time I get gas since this happened. Now, last night it overheated again! I wasn’t doing anything usual in it, and in fact I checked it yesterday morning and the coolant level was okay. Now when I popped the reservoir to put more into it, the coolant was rusty, and almost brown looking again. I had originally thought someone put stopleak into the radiator to keep it from leaking? But now I’m beginning to think it’s the head gasket. Anyone have any ideas? Maybe somewhere I could try to start?

 

[Dirtman]

It often takes several flushes to clean a really dirty cooling system...

You could have a bad water pump, stuck thermostat, clogged radiator, bad radiator cap, or the system is just still full of too much gunk. I'd replace the thermostat and radiator cap no matter what since they are so cheap. Then Id remove the upper and lower radiator hoses and run water through the radiator to see if its flowing properly (help to flush more gunk out anyway). Then flush the block and heater core seperately. Next pull the belt off and grab the water pump pulley and check that it spins nicely and has no wobble to it.

If you wanna check the head gasket do the RonD glove test... Take radiator cap off and put a latex glove over the opening (make sure its sealed air tight). Then start the truck. The glove shouldn't move. If it bounces around you have a blown head gasket. But im thinking you just need to do a better job cleaning and flushing the system.

I'd also check the computer for any codes to see if the engine is running too lean. Lean engines run hot. You can also pull the plugs and look at them. Black means too rich, grey/white means too lean, tan is running good, if they are spotless like they've been steam cleaned is also a good indicator of a head gasket leak.

 

[alwaysFlOoReD]

Simple check for a head gasket leak to the cooling system is the glove test....
@Dirtman beat me to it. Follow his advice.

 

[Dragonfrootz]

Thank you guys, I appreciate it. I’ll be showing these to the person that will be working on my truck. Unfortunately I myself can’t really do the work as I don’t have the knowledge but I mean hey looks like I’m about to learn.

 

[adsm08]

When dealing with an overheating condition there are three things to consider, mostly about when it is happening.

How fast does it happen? Is it in the first 10 minutes, or does it take longer than that. If less than 10 minutes suspect thermostat, if longer, suspect other things.

Does it happen sitting still, or moving? If sitting still it is more likely the cooling fan. If moving it is more likely a flow issue.

Once the engine is warm is the whole radiator warm, or does it have a cold spot, or spots. If the whole thing is warm then the water pump is likely going bad. If the rad has cold spots there are clogs or blockages.

 

[19Walt93]

When you're flushing it make sure to pull the block drains and also flush through the heater core( backwards first,then forward). I'd also look at the radiator to make sure the cooling fins are in good shape and clean.

 

[alwaysFlOoReD]

When you're flushing it make sure to pull the block drains and also flush through the heater core( backwards first,then forward). I'd also look at the radiator to make sure the cooling fins are in good shape and clean.

Where are the block drains? I didn't know there were such things.

 

[Dirtman]

There's a couple small pipe plug fittings under the rear freeze plugs on either side of the block. Im always afraid to touch them though.

 

[19Walt93]

If you aren't pulling the block drains all you're flushing is the radiator. If the coolant is clean and you're just doing a drain and refill with some fresh stuff it's probably OK, if it's dark and rusty the drains need to come out.

 

[Dragonfrootz]

Does it make a difference that my AC doesn’t work? We haven’t been able to do anything because it snowed yesterday and today my friend wasn’t available to look at it. I started it up and noticed that the coolant doesn’t seem to be flowing from the res to the radiator. But I didn’t move it just let it run and watched so I’m unsure if that’s even really anything. Just checking back with updates. Thanks again.

 

[adsm08]

A/C is irrelevant. Your coolant reservoir is just an overflow bottle and not part of the circulation, so also irrelevant.

 

[Dirtman]

If you aren't pulling the block drains all you're flushing is the radiator. If the coolant is clean and you're just doing a drain and refill with some fresh stuff it's probably OK, if it's dark and rusty the drains need to come out.

I pull the t-stat, disconnect the rad hoses and then run the garden hose through the upper rad hose for 5 or so minutes to flush the block...