My '93 3.0 Ranger (160,000 miles) has been overheating recently. In Dec 06, I put in a new water pump and thermo. So I figure the system must need to be flushed out and I plan on replacing the thermo and radiator cap. However, when I attempted to drain the system nothing came out of the draincock. I filled the radiator with water and it's still not draining - I guess it's clogged. I warmed up the truck thinking the pressure would push it out – nope. I tried using a plastic zip tie to poke up the drain hole and it didn’t accomplish anything. Any ideas how to unclog it?

Also, any ideas what would make the truck run hot beside what I plan on replacing?

 

What kind of shape was the old coolant in & what kind of shape were the water pump impellers in?????

Had the coolant ever been changed before???

Things, or combinations of things that'll make em run hot, clogged radiator fins, from mud, bugs, plastic bags, ect, slipping drive belt from coolant. or oil deposits, or weak belt tensioner, bad fan clutch, worn water pump impeller, stuck thermostat, rusted/sludged up system, from coolant neglect, clogged up radiator passages from coolant system debris or corrsion from coolant neglect, bad radiator cap, collasped lower inlet/return radiator hose, over advanced timing, lean air/fuel mixture, vacuum leaks, are some of the things that come to mind.

 

The old pump that I changed out just over a year ago had pretty worn impellers. I put new coolant in when I changed to water pump and thermo. Before that, I don't know because I picked up about a year before the water pump went. After taking the therm out and replacing the housing to run through some radiator flush it seem to be running on the cool side. Hopefully it was just a faulty thermo.

However, I'm starting to think about a possible head gasket lead since over the last few weeks it seem to always run low on coolant. If it had a head gasket leak, would the engine still be running smoothly?

 

I'm going to guess that the radiator passages are simply plugged. When these passages are plugged, your coolant simply flows from hose to hose. As such, the coolant does not dissipate any heat. I believe that you need to replace the radiator. If you do, for the fun of it, pull the side caps off of the plugged radiator. I believe you will see what I mean. The coolant passages are flattened tubes and the inside passage of these tubes is very small. Little pieces of junk plug each tube's input end. Pluged radiators happen to all of us that do not drain, flush and replace with new coolant at recommended intervals.

 

Good feedback on it using coolant. does kinda sound like it may have a head gasket problem, if it's using coolant, overheating & you don't see any signs of a external coolant leak.

If it were just oveheating, without coolant loss, then maybe a clogged radiator or sticking thermostat.

Do a coolant system pressure test, or a engine compression test, or cylinder blowdown test, or maybe a cylinder balance test with a scantool, could give a clue as to which cylinder/s to suspect, so you could pull the plugs for inspection & do a compression or blowdown test.

Sounds like this puppy has had it's coolant maintenance ignored for a long long time, so it's probably not in very good shape inside.

If it's overheated badly, you might have warped heads, so if you find the head gaskets gone & it's had a serious overheat, be sure to have the heads inspected for flatness, before replacing the head gaskets.

I'd also make sure the radiator is in good shape too, after doing any head work.

Maybe a radiator shop could give you some inputs about cleaning it out, or just replacing it.

 

Drained the system, took out the thermo and reinstalled the housing and ran it with Preston flush and water for 10 minutes. Drained it again and refilled with water and ran for 10 minutes. Drained it out, replaced thermo a 180 degree new one and refilled with coolant/water. Test drove for a while and made a few stops and different stores. Meter was looking good most of the time. On the last leg of the trip, the temp meter got up to just below the maximum safe zone. After I stopped and got out, staem was coming out of the over flow cannister tube. Ugggg! I bought the water pump at a NAPA store. Any chance that could have gone bad in 13 months? When I was working on the truck, I could see a good flow of fluid shooting near the radiator cap. If the radiator is clogged would the fluid still be flowing nicely near the cap?

 

Probably. Either your radiator is clogged or your head gasket is blown. Start your engine and look for bubbles out the top of your radiator cap.

 

I am not sure how true this is. But if you mix the green radiator coolant with the red, it will turn to sludge. You can mix it up to 25%, after that it becomes thick. Could have this been your problem? Did you mix RV radiator fluid in there?

Could be a few things now. Blown head gasket, cracked head, intake gasket, Water pump, someone used stop leak at one time (say it's not true), air trapped in your engine still. Is your heater blowing hot air, or is it cold? Is your oil looking white or milk looking after it warms up? Perhaps drain your radiator again and see if the chunks come out, you can always put it back in when your engine is cold and if fluid is clean. Make sure the air is out of the engine, bleed the air out if you have to.

 

The water pump usually drips water on the bottom of it when it goes bad. Do you have an electric radiator fan? I have had new thermostats go bad on me before. Perhaps take the thermostat out and see if it still overheats, while your at it you could have your radiator checked out or flushed.

 

What would bubbles mean?

 

Never used red fluid. The heater is blowing hot air. When I filled up the coolant it only took about 1.75 gallons instead of the 3 gallons the maunual calls for so it makes sense there is ari trapped somewhere. How would I bleed the trapped air out? I've tried topping off as it is runnning, but after a couple of minutes the fluid starts to rise above the cap inlet and spill over. I was thinking about taking the thermo off and filling it from there - make sense? I haven't check the oil yet, but will this morning.


As for a loose belt being the culprit - when the engine is running the fan is turning and since the fan mounts to the water pump I assume all is ok there.

 

Bubbles generally mean that you have a bad head gasket/cracked head. Dont mistake them for just air bubbles being purged out. Also its possible to have a blow head gasket and no bubbles. The bubbles come from the compressed air in the cylinder escaping through a coolant passage. Usually it will overpressurize your cooling system and blow all of your coolant out of your overflow (worst case anyway).

 

It won't drain at all? Sounds like a plugged radiator to me.

 

I am not sure the best way to bleed the engine in that year. I had to bleed my 2001 Ranger 4.0L engine yesterday through the heater core hose, when the engine cooled off, and got some air out...and it was just enough. But then again, my engine warmed up and then the temperature needle dropped to cold, indicating an air pocket around the temperature sensor. I was also blowing cold air through the heater. Sounds like you got the air out of the engine though, your blowing hot air, and your gauge steadily rises and don't drop immediately to cold.

Considering you engine still has a lot of coolant in there that doesn't totally drain out, putting in close to 2 gallons is about right. Warming up the engine, then letting it cool, in cycles seems to work some of the air out of the engine. Just make sure the over flow reservoir has enough in it to suck the fluid back into the engine. Mark the reservoir to see how much it fills or drops when the fluid cools and fills back in, lowering levels after it cools indicate air pockets, leaks, or coolant going in the oil. Air bubbles indicate a crack in the head. Is your oil white or milk looking, you didn't answer that?

I wouldn't bleed from the thermostat, it would be messy and you would probably just get air pockets back in the engine, and it might ruin the gasket. Perhaps bleed from bleeder bolt on the high side of the engine (if there is one), or if the temp sensor is high on the engine...loosen it up and see if some air comes out without the engine running. Sorry for the scattered brained long explanation, I just woke up.

 

To purge any air from the system park it so the engine is on an incline . With the engine cold remove cap and allow to run till warmed up to purge it of air and top off antifreeze and reinstall cap.