My 95' is overheating like crazy. It doesnt take more than 5 miles on a 90 degree day that the antifreeze boils over and starts spewing out the radiator cap and/or the overflow tank. What might be causing this? I already have a new radiator cap but that wouldnt seem to explain the boiling so quickly. Thanks

 

Sounds like a blown head gasket. Check your oil for water in the oil.

 

Is your themostat stuck closed?This also would cause the coolant to boilover and back into the tank.

 

Probably happening because it is a pink truck.

 

I just drained the oil because the head gasket would royally suck. I dont know exactly what to look for but the oil looks like oil. Rich and black and as it normall looks. The old boy can always use an oil change anyway.

I hope it's just the thermostat. It's only like 4 years old though. Took like 2 weeks to replace it myself back in college during my spare time. Took like 6 tries to get it installed and not leaking. lol. This time I'll take it to a garage.

 

Is the water pump working?

 

If there is water in your oil,you would see it.The water will "float" on top of the oil because the two dont mix.If all you saw was oil,then your problem lies elsewhere.Why did it take you 2 weeks to replace you thermostat?Its 2 bolts,off comes the housing,remove the thermostat,clean your housing and mounting surface on the block,a little rtv,drop in the new thermostat and put it all back together.I hope you find your problem,what ever it is,good luck.

 

how many miles on her??? grab the fan and try to move it up and down. your water pump could be gone.are your upper and lower hoses getting hot? is there any coolant even circulating thru there??

 

If the water pump is turning, then it working. Water pumps get replaced because they either start to leak or the bearing fails. Poorly maintained cooling systems will see deposits form in the pump that will reduce flow, however. How old are the hoses? The lower hose could have collapsed on the inside restricting or blocking flow. It makes no difference how old the thermostat is, I've had brand new ones right out of the package that were bad. Some thermostats can last 2 years, others go 10 or more. There could be a blockage in the rad, if you have a fan clutch that could be bad as well.

 

The first thermostat took two weeks because we were in college and busy and it wasn't a priority. But we did have a lot of problems with leakage. We tried everything from gaskets to gasket maker and it leaked probably 6 different times. We even broke one cast thermostat housing in half.

I assumed the fan was fine because it is attached to an engine pully and I didn think it could even stop moving so long as the belt was in place.

The upper hose is older but seems fine. The lower hose isn't that old, and it's a jerryrigged hose with two hoses combined with a copper bend. A bit of custom work when I added the 3" body lift and we couldnt find a hose to fit.

I dont know how to tell for sure if the antifreeze is flowing, but if it wasn't flowing into the engine, I assumed it couldn't get hot enough to boil over.

There are like, 120K miles on the truck. I'll try and checkout the water pump and fan tomorrow.

 

Well I went outside with a flashlight.

Belt....Check
Spinning fan...Check
Fan does NOT go up and down by hand
Squeezing both lower and upper hoses causes noise in the radiator
Visual inspection of radiator does not reveal any obvious problems.

I need to take the truck on a short 3-mile drive tomorrow, I'll check the heat on both hoses.

 

the impellers in the water pump can wear out. its rare but it does happen .usually a bearing will go before that but...thats why i asked the mileage.

 

Okay, so I ran a quick errand with the truck. Exactly 2 miles each way.

Starting Temps: 95 Degrees outside
Upper hose: 115F
Engine: 40F
Lower Hose: 50F
Radiator Cap: 100F

Mid Trip temps:
Upper hose: 180F
Engine: 145F
Lower Hose: 160F
Radiator Cap: 100F

Returning Home Temps:
Upper hose: 200F
Engine: 160F
Lower Hose: 170F
Radiator Cap:120F

By the end of the trip, I could hear the antifreeze boiling.

It's starting to look like the thermostat is the only remaining possibility

 

Grrrr. So I took the truck into Meineke on Monday to get a new thermostat put in.

They did that but it was still over heating.
So then they tried flushing the system. Still over heating.

Now they think it could be a head gasket. They're trying to get a hold of some kind of exaust gas tester thing to see if that tells them something about the gasket. I did drain the oil and there was no water or antifreeze in there so I really dont know what to think at this point.

All I know is it's getting expensive and there is still no solution.

 

Did they pressure-test the new radiator cap or the cooling system? Did they check the specific gravity of the coolant? Did they test the fan clutch? (Read how in this thread.) Did anyone check the coolant temperature WHILE it was boiling? Did they flow-test the water pump or radiator? When the coolant is boiling, are all the coolant hoses difficult to squeeze? Is there steam coming out of the overflow tank?