Back when I got my truck in the summer I found out that it ran hot and would blow coolant after a hard run on the highway. I spent some time on a bunch of forums and read all sorts of horror stories about how bad the 4.7 is and how they overheat and totally crap out.

Anyway, if your 4.7 runs at the middle range or higher you need to check your rad to see if it's plugged up. Just feel around the front of it when it's hot and see if you find cold spots. I don't think my rad was passing any coolant through it!

I thought I'd post this for any other people who buy 4.7s and find that they are boiling over. The symptoms I read about were all the same as mine and it was an easy fix. Everybody was just hesitant to replace the radiator because it's the most expensive part of the cooling system and the trucks are pretty new so the rads shouldn't be a problem. This isn't the case, they plug up really good for some reason.

Cheers, Steve

 

What year is yours??

 

It's a 2004. It had about 90 k miles on it when I got it, now I'm up to over 100 and it runs great.

I started with changing the coolant, thermostat and pump first with no luck. Only changing the rad helped other than the pump was ready to wobble off the front of the engine.

Steve

 

Steve, you replaced the radiator?
In your opinion, would a flush fix that when its clogged rather then spending the money to replace a radiator?
It used to run a couple a couple mm before the half way mark at operating temp; after a water pump replacement it run middle and a little higher when at interstate speeds.

 

I honestly didn't try flushing because I can't get anything good to flush with. The stuff they sell these days doesn't work at all. I pulled the ends off the old radiator and it had some really hard flaky stuff on the ends and in the core. From what I can tell flushing wouldn't have helped because it wasn't possible to push any liquid through the rad.

 

Thanks, yeah going to check mine tomorrow after work the other day she overheated on me, just added some more anti-freeze to the overflow tank and it hasn't overheated yet so hopefully its just the radiator plugged a bit.

 

ive had two hose burst on me, a water pump break and a chunk of plastic get stuck in my thermostat so i feel ya one this one. i ended up when i changed the water pump flushing out the radiator twice to make sure everything was out. ever since then its been alright but i just found out the coolant is the right kind so i have to flush and change the coolant

 

I'd get on that right quick if I was you.
The cost of a new rad compared to an engine rebuild, just doesn't add up.
Al.

 

Hey guys,

I've got an 02 with a 4.7 and mine started overheating at 1115,000 miles. I did the thermostat twice and the water pump and that fixed it for about a month. The last time it overheated, the upper return hose on the radiator was bulging and expanded like it was about to burst. No fluid was re-entereing the radiator because it was clogged so bad. So I ordered the radiator off ebay ($100 shipped) and installed it last night, in the rain. I only had half a bottle of coolant with me, so I put that and half water. I let it run til it got warm and it didn't over heat. I revved it up for a little while and it started to heat up but kind of levelled off, but it didn't cool down. The air was blowing ice cold though, it wouldnt warm up. I'm gonna put more coolant in it today and drive it around to see if it's fixed. If not, I'm trading that sh*t in...Hello Hemi .

 

Are you using distilled/de-ionised water topping up?
If not, the hard water may by causing a "fur" build, up a bit like a kettle.
Al.