ATF is clean too. Coolant looks good. PVC rattles just fine. Definately moisture in the exhaust. After the motor is at operating temp. If you nail the gas a huge ploom of white smoke comes out. I have let it idle in the driveway for more than 2 hours just to make sure that the cat is hot enough and it wasn't condensation or something. Wierd thing is that my engine temp doesn't fluctuate. At least my 5.0 did that. After letting the truck idle... the radiator hose never retained any pressure. Just a wierd situation.
Kevin

 

man not to sure about this. from what you say is that it doesnt over heat or use water. that there doesnt sounds at all like a head gasket. im stumped for right now. but if it was your intake you should be able to pressure the cooling system then bar the engine over by hand. and watch each cylinder to see if you get water in them afterbaring the engine. thats all of my ideas to help you right now. other then take a flash light and look over the intake really good to see if you might have a little leaking out around also.

 

This one's got me thinking too. A couple more ideas... You could try to blow compressed air into the cylinders (with the plugs pulled obviously) and with the radiator cap off. If the radiator gushes out water or if you see a bunch of air bubbles, you got a bad HG or a cracked head or block. You could also test your radiator for the presence of exhaust gases (or have a shop test if you don't have the equipment at your disposal).

Have you had to add coolant since you noticed the problem and how much did the level drop in how long?

 

IF the intake is leaking and he puts pressure to the radiator it might not go into a cylinder.

IF the intake valve is closed it might fill up the runner and then start filling up the intake.

 

Are you sure the manifolds are the right ones and they didn't change during the years of production? I'm not sure if they did, just a thought.

 

I skipped a lot of stuff....but Harbor Freight is no place to buy precision tools. I built my own leakdown and compression gauges using rated gauges from Grainger. Surprise surprise--The HB tools were crazy off and crappy.......

 

clicker torque wrenches are all off as well. but we most of us use them. Dial types or beam types are actually the most accurate. Which is why the nuclear mechanics in the Navy never use clickers.

Same thing goes for 12pt sockets vs 6 point sockets/wrenches. Most of us tend to use 12pt, but 6pt are the ones we "should" be using. Which is why the nuclear mechanics in the Navy never use 12pts.

 

ok read the thread--FYI--i would be careful you dont hydrolock the bottom end also....

Pull the plugs and see which ones are clean--then pull the intake--not to hard of a job.

There is also a coolant-to-oil heat exchanger on the side of the block. Looks like a short can with a bolt in the middle and two hoses coming off....

But if you are not getting coolant after pumping up the cooling system i would move on.....maybe throttle body issue--MAYBE you have the TB coolant lines and Air injection line hooked up wrong.

The coolant would fill up the Air injection cavities in the lowest intake manifold and then get atomized and sucked in when you ran it.

just throwing ideas

 

I thought around 170 was Good?

 

So what ever happend here?? It really sucks when you dont get a conclusion to a problem like this......

Your issues and resolutions help others FYI....