I need some help. I have a 89 F-150 inline six. I replaced the water pump last week and assumed I had solved my overheating problem. Then the upper radiator hose got so hot it busted the plastic connector nozzle clear off with the hose still clamped on. So I replaced the radiator. I also replaced the thermostat but discovered that the engine was still overheating. Since its summertime, i completely removed the thermostat. When I start the truck, I still do not see any water flowing through the radiator and engine seems to get hot fast. I decided maybe the pump might be bad but it was brand new. Any other suggestions before I tear into it again? Also, coolant seems clean when it drains so i don't think there is massive clog or anything.

 

When you say you discovered the engine was over-heating do you mean the coolant gage showed the engine coolant was too hot?

Is the engine still getting too hot since you removed the thermostat?

 

The engine is still getting too hot even when I remove the thermostat. The gauge might be broken but I am going by the temperature of the engine and the fact that the water sitting in the overflow tank was boiling. (as in get some spaghetti it's Italian night) I have completely taken everything back off and looked at the water pump, it seems to be working fine. what could be preventing water from circulating?

 

Does it look like a radiator hose my have sucked itself shut?

Is the fan cooling fan operating properly?


Is the water in the overflow tank really boiling or is it air from a leaking gasket escaping? Maybe cylinder pressure is seeping out a bad gasket into the coolant which in itself could create air pockets in the coolant system and cause the engine to get hotter.

I am thinking a compression test of all cylinders and see if the cylinders hold pressure. If the pressure in a cylinder goes down quickly you might be able to hear bubbling with an engine stethoscope.

 

Dood.....its overheating BECAUSE you removed the thermostat. You can't do that in hot temperatures. That thermostat regulates the flow of the water in your engine by slowing it down long enough to absorb the heat. You remove the thermostat, the water is probly gushing thru so fast it can't absorb enough heat and move it to the radiator to cool. Get a NEW thermostat, whatever the manufacturer recomends and put that thing back in.

 

I would suggest taking truck to radiator shop. There they can flow check it. This will tell them if radiator is providing proper cooling. And if it is stopped up they can remove end caps and rod it out. This procedure will allow radiator to provide proper cooling for engine.

 

Actually, after reading newsgroups on the net, i see that they say removing the thermostat altogether will NOT cause it to overheat and that what i just wrote is BS. So....i don't know. I did read that if you remove the thermostat, the pump can force water thru the system so fast that it can SIMULATE a boil over...so thats something else to think about. It sounds like a block in the heater core maybe? If there is a block, and the pump is still pumping water, then it has to come out somewhere. Have you tried firing up the truck when its cold, without the thermostat, and given it a few good gooses to get the RPM up higher to maybe unclog whatever is plugged? Just keep an eye on the temp.

 

The flow check sounds great!

Where did you get your replacement radiator?

I don't know when Ford started using degas bottles but is yours really an overflow bottle or a degas bottle?

What is your water/anti-freeze mixture?

Is your coolant system maintaining pressure? Mine is supposed to be at 16psi and it has a degas bottle. This pressure raises the boiling point of the engine coolant.

 

My previous F150 was a 1991, purchased new Radiator from Autozone approx. $140.00, lifetime warranty. New radiator was all metal, no plastic end caps like on original. And they had it in stock too.

 

Another thing...you can get a prestone flush kit at wally world for a couple bucks. You can flush your coolant into a bucket and save it, then run pure water thru the engine with the water hose. Without the radiator, you can fire it up, rev it a few times, and IF something comes unlodged, it will come out the top of the engine with the water, this way it doesnt recirculate back thru and jam somewhere else........just an idea if the rad. flow test yields not results.

 

Sorry GCOLE, I was addressing Dhaus99.

Dhaus99, where did you get your replacement radiator?

 

thanks for the suggestions, I will take it to a shop tomorrow to check pressure. One other thing, when I was driving it the other day (before all this happened) after about 30 minutes, the engine started to kick up to about 3500 rpm when I pushed the clutch in. Then I started hearing a really high pitched squeaking. It was the oddest thing. If it was in gear, it ran normal, besides being extremely hot. Could this be a symptom of a blown gasket? Does water not circulate when you have a pressure leak?

I got the "modine radiator" from a place called ACE Radiator. Cost about $135. why do you ask?

 

I just wanted to know that you got a nice clean radiator and not one that might have clogged passages from a junk yard.
Does it have an electric fan or an engine fan? Is there a shroud around the fan?


Does water not circulate when you have a pressure leak?

The water will circulate but will bubble/boil at a lower temperature. Heat transfer through air sucks compared to water so air bubbles and pockets must be kept from forming in the coolant system.

The coolant system is usually a "closed" system meaning only excessive pressure should escape. My 1999 F150 for example should run around 16psi of pressure. This 16psi of pressure raises the boiling point of the coolant. Also consider that anti-freeze raises the boiling point of the coolant.

http://auto.howstuffworks.com/cooling-system3.htm

Then I started hearing a really high pitched squeaking. It was the oddest thing. If it was in gear, it ran normal, besides being extremely hot. Could this be a symptom of a blown gasket?

I don't know but its kind of the chicken or the egg thing. Which comes first. Is the engine overheating and overwhelming the coolant system's normal heat removal capacity or has the coolant system's heat removal capacity been reduced (a failure in the coolant system) thereby causeing the engine to overheat.

Lets say for example that the water pump failed but the engine was driven in an overheated condition and engine damage occured (blown gaskets, etc.). You find the water pump is bad and replace it thinking all is well. Now the engine produces too much heat for the coolant system to remove and the coolant boils yadda yadda and the conclusion is that something else is wrong with the coolant system when in reality the overheating has moved from the coolant system to the engine if you catch my drift...

Heres some links...

http://www.raysradiator-hotrodshop.c...%20failure.htm

http://www.babcox.com/editorial/us/us80222.htm

http://www.fatcity.net/overheat.htm

http://www.carrsmith.com/cooling%20system.htm

http://members.shaw.ca/autocheck/overheatingc&c.htm

 

Truck has a fan shroud, and an engine fan.

Where is a good place to get updated information on head gasket removal and replacement on the internet? My dad has a torque wrench and we are going to tackle this over the weekend. I want to make sure I have really good instructions though, as I read that improper installation is the cause of many problems later.

 

Did you look at some of those links above and determine that you have a bad gasket? Did you do a compression test on the cylinders? Please don't assume that its a gasket because I mentioned it as a possibility.