having overheating issues. 94

[Modrod]

Highway driving is bad. 70. Is Max any more and it will run hot. Coolant is maybe a resivour full every 500-800. Not been paying to much attention.
Before the new radiator went it I flushed the block and heater core. Then did water pump and tsat after, so the block it flushed as much as possible. I know these rigs suck at maintaining engine temp. But I'm not asking it to do anything extrodinary here.
Rig is a 94 168k aw4 bout 5 iinchs lift with 33 4.56. stand alone b&m cooler stacked plate style,. Biggest that will fit in front of mechanical fan. With same cooler for ps. Radiator trans cooler not plumbed.
Ac works great.

I know this is an old thread, but I wanted to ask if the engine has had the head gasket replaced prior to the overheating issues. I've run into a problem where I overheat on the highway after replacing my head gasket after a valve job. The new FlePro gasket is missing all of the water port holes down the length of the gasket. Maybe driving around town this is fine, but on the highway going up hill or going 75mph plus it starts to heat creep. Everything is new and checks out. The only thing left is the head gasket missing the water port holes. And yes, both the head and block have the holes where the factory head gasket had the holes on it. So my last step is to do what some shops apparently doing and to drill out the holes in the head gasket. I think at higher rpms it is hindering the cooling of the cylinder head and overheating the engine.

 

[Rob Mayercik]

Odd that the gasket has holes missing - there's no note in the box with it about this?

I cannot help but wonder if maybe you got a gasket for the 245 (4.2) instead of the 4.0, because it doesn't make sense that a company like Fel-Pro would get that sort of detail wrong - it's not like the 4.0 is a brand-new engine design that just hit the market. Maybe it'd be worth reaching out to them to double-check that there wasn't some sort of labeling or packaging error when that gasket was made?

 

[Unclewolverine]

We're there NO holes, or just small ones? Because every head gasket I've seen has small holes where there are large sections in the water jacket. This is done to slow down the coolant flowing through the engine so it has time to absorb the heat from the metal and so that the coolant circulates more evenly otherwise it would just take the quickest path and over heat the rear cylinders. Your problem in particular is probably crap got stirred up in the system and is restricting the flow through those holes, a backflush may help. Unless you're not running a thermostat, like that other guy who is having weird cooling problems that I have repeatedly told would go away if he put a thermostat in. In that case, put in a 195 stant super stat.