Overheat

[mvalenz]

Appreciate some guidance,

I've a 2004 Ford Expedition, latelly I've notice that coolant comes out the coolant pressure bottle and periodically I've to add coolant to the tank. I've noticed that after getting the vehicle warmed up the gauge read 3/4 up, no longer half way. I also notice some small bubles coming from the coolant hose from the engine that goes to the tank. I've performed a head gasket test and did not notice any color difference on the results, also did a coolant flush with the thermostad taken out drove the truck yesterday and no overheat. any suggestions. Do I've an air pocket? do I have a blown head gasket? any recomendation would be greatly appreciated.

 

[Bedrck47]

There is no need to post the same question in two different areas all you will accomplish is jumping from your threads to see the same answers Everyone on the forum gets to read all the post

 

[Ripp]

So you took the thermostat out did u put in a new 1?or the same old 1

 

[stamp11127]

If you don't have the "special tools" for a proper diagnosis the first thing you could do would be to test the thermostat in boiling water. It should open near or at the rated temperature. If it doesn't then that is one possible cause of the higher temps and puking coolant. I would replace the thermostat with a name brand and test the system again.

 

[04ExpeditionEB]

I would say if your system did not over heat after the thermostat was removed, then more then likely the T-stat was bad and held from opening too long allowing the system to boil over. this builds up pressure greater then the capacity of the radiator cap (located on overflow bottle) this introduces air into the system and pushes coolant out.

Did your ride ever go critical? temp gauge peg out? system info tell you its too hot? If you puked all your coolant it may be too late. had this happen on my 4V intec and then it was game over. I wound up replacing water pump, t-stat, radiator, hoses, crossover tube seals. and gallons of coolant till I sold the car. Although never confirmed head gasket,(also checked for gas in coolant (tested negative) ) I could never get the car to settle down after the boil over.

Things to check obviously.. oil - does it look milky?
Coolant, do you see oil in coolant?
overflow bottle cap. is it old and not holding the proper pressure of 16PSI?
have you checked for proper temp in the radiator after up to temp? should not have clear cold and hot spots in system. should be a uniform heat all around, until the thermostat is open then for a little it will be hotter while coolant cools off.

Good Luck.

 

[mvalenz]

Update,

I performed a pressure test with no thermostad in the system it ran for over half an hour and no pressure change.Today I drove it to work no signs of overheat however there were sings of coolant overflow at the tank.

 

[04ExpeditionEB]

Update,

I performed a pressure test with no thermostat in the system it ran for over half an hour and no pressure change.Today I drove it to work no signs of overheat however there were sings of coolant overflow at the tank.

I had the same, you have a blown head or a cracked head. its pushing pressure from the calendars into the coolant passages. causing excessive pressure to push coolant out (that being said, have you replaced the cap or had it tested? 16PSI it can be bad. I did have a bad one that did not hold back the pressure.
Either way good luck.

P.S. A static pressure test may not be conclusive enough. you may have to go through a drive cycle to see if pressure fluctuates too much. I know water pump will create pressure but it should settle down.

 

[mvalenz]

Overheat Overboil

Please explain how come this does not happen from the get go when I start up the vehicle. It seems to take a while for this pressure to build up, also why did the block test came back negative? how much did you spend on your repairs?

 

[mvalenz]

Overheat Overboil

please explain how come this does not happen from the get go once I start up the vehicle.

 

[stamp11127]

If the head gasket is blown and allowing cylinder pressure into the cooling system your pressure tester will show a very high increase in pressure over the 16lbs the system is rated at. It usually shows up quickly once the engine has started. A minor leak or cracked head will take longer to show up.

If the water pump has failed or is failing, the flow is reduced enough it will allow the coolant to boil, increase the pressure and vapor over time.

Do you hear the fan clutch engage at any time?

If you have an IR temp gun it would help with the diagnosis. That way we would know the outlet coolant temp.

Since a combustion gas test has showed negative I would be inclined to pull the water pump for inspection/replacement. Once it is out you are able to see the condition of a part of the cylinders. If scale is present then the radiator may also be playing a part in this.