Overheat again!

[Reverend]

I recently got rid of the overheat problem by changing alternator belt and thermostat. Now its back and worse than before. Car warms up normally but soon heat starts to rise and nears red.

I switched it off and i could hear "gulp gulp gulp gulp" kinda sound from the engine/radiator and there was white smoke coming from carbs.

Also i noticed that there was water dripping from water pump area. Could this be water pump related problem? I found it hard to believe but my head is empty and i cant figure out anything else..:stupid:

[Zs-ondabrain]

I would do a complete Flush on the cooling system, Pull the water pump and replace it if it's leaking. "Gulping" sounds usually indicate Air in the system. So after filling back up after the flush and R+R of the pump, Park the car on an Upward slope, pop the radiator cap and let it runn for a bit, filling the radiator after the air is "Burped out"

make sure the valve is open on your heater core when doing the flush, so you get all the crap out and don't burst a line.

Dave

[EScanlon]

Could the impeller in the water pump have gone bad?

It sounds as though your water pump is gone, not only due to the leaking, but that you're not pushing the water around.

That "gulping" may be the coolant boiling.

FWIW

E

[manny1973]

I had the same problem, Changed the water pump no help. It turns out the head gasket was bad. probabally due to over heating. I put on a new head gasket, That solved the problem

Good Luck

[Zs-ondabrain]

That was my thought as well, that's why I suggested the Water Pump R&R, Pull it, inspect and reinstal or replace. You're right though, the gurgling could be a boiling sound as well.

Dave

[olzed]

Iv'e had similar on my 240. After draining and refilling the radiator it started to overheat. Realised it had an air lock so loosened the engine side hose and purged the air as it was running, at the same time filling radiator with hot water.Iv'e had this a couple of times over the years, and yes, glug glug glug!!!

[Reverend]

Hiya! I've changed the pump and there had been issues after that too.In first startup after pump change it overheated, possibly because there was huge amount of air in the system. I could see it bubbling from radiator and after the thermostat opened all the water in the top radiator just disappeared in to the depths of engine. Well, i added more water/glykol and go for a spin. It DIDNT overheat. I was happy.

Now next morning i go for another spin and it DID overheat AGAIN!! Well i opened the hood and scratched my head but all seemed fine. I started the car and heat stayed normal, actually it has stayed ever since. I drove about 2 hours straight and heat stayed normal. Hmmm... What might be the reason for that..?

Well i found other "minor" thing while cursing with the overheat. Radiator is LEAKING! Leak is small and you gotta drive a lot (hours) to use all the fluid in the radiator.

Its leaking in front of the radiator, just in the weld between upper tank and radiator core. Can this small leak cause overheating? It's on my top priority to repair it before doing anything else.

[ozconnection]

You're not having much luck with this one hey?

A leak in the radiator is just that .....a leak. The cooling system must be completely sealed for it to work properly. It must be able to contain pressures of up to 30 psi in the water passages in the block and prevent air entry after shutdown.

Air in the cooling system is compressable. Water is not. Air in the system, entered into via the small radiator leak will prevent pressure from building in your cooling system and thus allow nucleate boiling, the water boils in the hot spot areas, the engine gurgles as the air pockets move around and your engine will overheat. Water pump cavitation is also a problem with reduced coolant pressure, so less water moves through your engine, and what does, overheats and perpetuates the problem with runaway overheating.

Fix all leaks. Don't discount a faulty headgasket even though your oil isn't milky. How old is it? Do you have a coolant recovery system on your radiator? Try a higher pressure radiator cap. I'm using a 20 psi one (up from the 14 psi one I had originally) and I swear that I've had zip problems with overheating.

You'll beat this, just keep at it.

Cheers.

[Reverend]

Oil is just changed and i've been driving with it about 50miles in this year. I'll take radiator to shop a.s.a.p.

[pwd]

I concur with Ozconnection. One of the most important tools to have in your toolbox is a radiator pressure tester. It should be the first thing used in troubleshooting a cooling problem. Cooling system problems can worsen progressively, to the point of cracked heads, blocks, etc. If the system has ever been significantly overheated, it could be a warped/cracked heard, or burned head gasket. (Note: always allow an overheated engine to cool down naturally to ambient temperature before filling with water) More than likely you have a defective hose, or radiator. Interior heater hoses and the heater core can fail and cause pressure loss too.

With the radiator cap OFF and the Heater Controls to full heat, run the engine up to normal operating temperature with the coolant level just below the tank filler neck. If you see water coursing through with no significant bubbles or pulsing, you probably don't have a breech into the combustion chamber. There are also "color change testers" to check for the presence of exhaust fumes in coolant. Also, if you don't see significant water in your engine oil, you probably don't have block related problems either. Now that the system is warmed up, fully open and full of coolant, replace the radiator cap. This ensures the pressurized system has been "bled" so that air is completely out. Often, when replacing a hose, water pump, etc. a significant amount of air is introduced to the system, which must be purged, or else you get reduced cooling, and gurgling.

[Reverend]

I got rid of the overheat. I took the radiator to radiator shop and they patched it up. Now its good to go. Now i have a new problem..leaking fuel pump... arghhh!!!

[Mikez73]

I got rid of the overheat. I took the radiator to radiator shop and they patched it up. Now its good to go. Now i have a new problem..leaking fuel pump... arghhh!!!

Congrats! Now does somebody want to explin this:

Iv'e had similar on my 240. After draining and refilling the radiator it started to overheat. Realised it had an air lock so loosened the engine side hose and purged the air as it was running, at the same time filling radiator with hot water.Iv'e had this a couple of times over the years, and yes, glug glug glug!!!