Curious IDI Issue.

[Camarogenius]

The guy I sold the red crew cab to just called and said that it's making pressure in the radiator.
He said that the Upper radiator hose is getting real hard when it's running.
I don't believe it's a head gasket, because the coolant is clean and beautiful. As much thick black smoke as that truck makes, if Combustion was getting into the coolant, so would the soot. also, that would mean that coolant is getting into the cylinder, and we all know what happens then.

 

[f-two-fiddy]

All radiator hoses should be hard, when the engine is at operating temp. They're running at 13 psi.

Usually if they're not hard, your losing pressure somewhere.

 

[Diesel JD]

When I blew head gaskets on the 6.9 I noticed
1) A drip of coolant near the rear of the engine
2) A sickening sweet smell in the exhaust
3) Bubbles and combustion gases in the radiator
4) Couldn't keep the overflow bottle or the top row of the radiator wet for more than a few days
Hydrolock may have been imminent but I sure wasn't getting any coolant in the oil. Several of the firing rings on the old gasket were compromised.... I doubt your old truck has blown gaskets...but it is common with the 6.9s and you shouldn't feel bad if it happens to him. I bear no ill will to the PO of my truck..it just happens and sometimes develops pretty quickly. Then again sometimes they just drip back there for a long time and never really hurt anything.

 

[tonkadoctor]

All radiator hoses should be hard, when the engine is at operating temp. They're running at 13 psi.

Usually if they're not hard, your losing pressure somewhere.

+1

If he was making too much pressure in the system because of a head gasket or cavitation the coolant wouldn't stay in there long..... Don't ask me how I know

 

[Agnem]

The guy I sold the red crew cab to just called and said that it's making pressure in the radiator.
He said that the Upper radiator hose is getting real hard when it's running.
I don't believe it's a head gasket, because the coolant is clean and beautiful. As much thick black smoke as that truck makes, if Combustion was getting into the coolant, so would the soot. also, that would mean that coolant is getting into the cylinder, and we all know what happens then.

He should do the obvious then, and run it up to temp with the radiator cap off so he can look for bubbles.