Overheating issue!!!!!! HELP!

[burtonkid87]

I have a 3.0 V6 ford ranger it's a 1999. In the past two weeks I had the cooling system flushed. I had a thermostat put on twice cause of the issue of overheating and the heat not working till given gas. After that I drove it to Michigan from Pennsylvania with no issue on the drive. I let the truck sit for 2 days at a friends. I started it she idle very rough for a few minutes I drove it up the street it overheated. I burped the truck and top it off with water she ran fine till I go to Toledo and it overheated when I was getting gas. So I repeated filling it with water as long as I stayed in the highway and driving she would not hear up till I hit places where it would have to idle. I got home and tried to get any air pockets out of her I placed the front end on uphill slant to get it to burp and the coolant lines. She drove fine for a few days then the same issue of overheating. I took it to Firestone and they couldn't figure it out they did a pressure test and they were left stumped and did not charge me as they said either water pump or airpockets which could cause rough idle. Though I have to put coolant into the system every couple days but no apparent coolant leak. I checked the oil to make sure there was no leaking into the oil. Which there isn't. No white smoke either. So anyone ever have a weird issue like this. I can drive the truck around fine as long as I make sure the coolants top off. All day no problems no overheating and got heat...so hellllp!?

 

[RonD]

Welcome to TRS

Do the Glove test to take blown head gasket or cracked head off the table.

It is easy and best of all FREE

Cold engine
Unplug Coil Pack, you want a no start
Remove rad cap
Coolant should be down about 1" from top of rad, or lower, drain some if not
Remove over flow hose, plug that port with vacuum cap or ??, you can put your finger over it if you have someone else to crank engine, read on.

Put latex glove over rad cap opening and seal it with rubber band, you can also use a balloon or even condom instead of a glove

Cooling system is now sealed

Crank engine, no spark so no start
Watch the glove
It should just lay there no movement at all
If it bounces then one of the cylinders is pumping air into the cooling system, which is a blown head gasket or cracked head

There is no delay it will happen as soon as engine is cranking

If you do get the bouncing or movement, then remove 1 spark plug at a time and crank engine.
When bouncing stops the last spark plug removed was from the leaking cylinder, reinstall it and crank again to be sure.
That spark plug will also look super clean, like it was steam cleaned, because it was.
Finding the leaking cylinder can be helpful after disassembly.

It reads like if there is a leaking cylinder it is a small leak now.

So you wouldn't see "white smoke" and engine wouldn't over heat all the time.
The cylinder pumps air into the cooling system and it will flow out of the head and get to top of rad and stay there, then be pushed out to over flow when engine warms up.
When driving at highway speed coolant is flowing fast taking away the air with it so no overheating, when RPMs are low air can get trapped in the head which blocks coolant flow also in heater hoses so heat goes cold, that's when engine starts to over heat.

People will replace thermostat, water pump, fan clutch, hoses, and radiator chasing an overheating problem.
Do the Glove Test first then you can go to the other stuff

 

[Andy D]

Over heating at idle is often a fan issue.

 

[RonD]

Yes, I thought of that but his description of heater not working until "given gas" reads like air was trapped and the increase in water pump speed pushed it out, or water pump impeller issue.
But the continued reference to "burping" the system and "topping" it off means air is getting in, and with no visible leaks and good pressure test................

Almost text book start of cylinder breach