apoirier594

I have a 99 ext 4.6 Auto 2wd.

My old radiator got a Crack on the seal and was leaking water. I was able to drive my truck under 60 mph no problems, could idle 24/7 and not overheat. As soon as I hit 70 the temp would rise.

I had a single row, I just installed a 2 row yesterday. Well now she is undriveable. It overheats just idling. The top hose is really hot and the bottom hose is very cold. My heater stopped working as soon as my old radiator got that leak and it's still not working.

Just bought a new T-stat which I need to install as well, could that be it? But why would it be fine at certain speeds with the leak and now overheats right away?

OTG02

Ok first off I am no expert lol. That being said. I replaced my radiator bout month ago and new t stat. Mine was doin same thing your is doin now. My prob was there was and air or many air bubbles that had to work out. I would start it let it run for a bit had the cap off the rad resivor and would shut it off when started to over hear let cool down and repeat. Also I had my hear on high trying to work bubbles out. Finally it did. That's what I did. I've also have the 4.2 so may be diff. I hoped I helped in some way.

Side note I replaced the rad because I blew both head gaskets LOL. a lot I replaced.

I am sure other with much more experience and know how will chime in.

4x4dave

Very well could be trapped air. Run the engine for a while with the cap off so you can burp the system.

blacknsb

What they said. I did a coolant flush on mine and had the same issue. Try applying pressure to the hoses to work out the air in the system.

w0lvez

I think your oil is below minimum. It won't overheat on idle if there is enough oil in the engine because of Fail Safe System. It will automatically stop injecting fuel on some cylinder randomly. Automotive oil today are full of detergent and additives that absorb moisture. It's almost impossible to detect oil consumption unless you drive it a highway for several miles to boil mositure and fuel out of your oil.

The reason you need to replace your coolant after a period of time is to prevent chemical electrolysis from happening that could eat the impeller on your water pump.

apoirier594

Thanks for all the help. My oil is a little above the middle on the dipstick marks.
I did park my trucks passenger tire only on a ramp and let it idle but nothing happened. Today I took the t-stat out and only ran the engine for 5 minutes cause I had my ride take me to work. I pored water in the reservoir tank and it wasn't going down. So it's almost like it's not going anywhere. Any ideas, is there any real way to bleed the air? Or how can I test for the water pump without buying a new one first? Thanks

w0lvez

You can either remove the cap or install and park the vehicle in a small hill with the truck nose pointed up run the heater and install the cap.

Look at the picture I posted above. You only need to remove 4 bolts + the fun clutch. But before doing it make sure you have a new water pump o ring.

Are you using distilled water mix with coolant?

The Thermostat available today have a small hole that will bleed the air out automatically.

Why not just use the old radiator and use stop leak. Ford also use this stuff.

Jbrew

You should use just the 192 and 194 stats for that engine. In the past, I've found plenty of these engines that were picky about which stat you use.

The way these trucks are set up can at times make them very difficult to burp.

What you have to do , -hangon I might have something from service here..(?)



Yep! , - follow that to purge and stay away from hot spots in the heads.

blupupher

iTrader: (2)

Stop leak products are a band aid, you need to replace whatever is leaking to fix the problem.

Jbrew

If that doesn't work, just lift the front end until the degas bottle (expansion tank) is higher than the heater core.



Hey, it's been done before and worked!