I noticed this week that even after driving my car (07 stx charger 3.5) for about a half an hour, and with the heater working well and temp guage between cold and halfway, my upper heater hose is still firm with alot of pressure in it. When i release the fill cap the pressure is relieved. Is this normel on this car? I never had a car that maintained that much pressure after a 20 minute drive. The thermostat should open and the pressure would go down. On a longer drive on the highway , about an hour and a half, the hose was soft with no pressure. I took it to the dealer and they said this is normal. They said they changed the thermostat a month ago along with the rocker arms about a month ago. Im not comfortable with the way things are. I feel this is too much pressure in the system. I worked on a lot of engines and never had this happen. Any advice would be appreciated.

 

My guess would be that the fluid hadn't cycled all the way through to the overflow tank. I've never noticed anything, but then again I don't check. Supposedly, it takes about 15 minutes for the warmup cycle to complete. This is what I've heard from our 3.5L expert.

 

I'm still wraping my mind around this one. I don't see what the issue is, help me out here.

 

The pressure in the top radiator hose remains as hard as a rock even after driving for 40 minutes(yesterday). MY temp guage reads between C and Half Way. The heat works fine but I'm concerned about that much pressure in the system for that long a time. Is this common in the v-6? thanks for replying.

 

I shouldn't type this in a thread that all can read but to tell the truth I never squeezed my hose on the 5.7

In all seriousness if your radiator isn’t spewing into the overflowing and isn’t leaking I wouldn’t worry about it.

The T-Stat should have a small pin hole at the top to releave pressure back to the other side when stopped. It will take it some time to fully releave the pressure.

 

I think I know what he is asking

Yes this is normal on all cars. Your cooling system will stay pressurized while the engine is hot. Hence why there is a warning on or near the radiator not to open it up until the car is cooled.

You say that you never have had a car that did this before, remember different engine sizes and car weights are going to result in different end results.

I do have to ask though, why would you check your radiator hose unless it was leaking. Just curious.

 

I checked under the hood (cooling system) because i smelled the odor of anti-freeze after taking a twenty mile turnpike drive. There was no obvious source of a leak but i could still smell a little odor. That's when I noticed the amount of pressure in the hose. I know that these systems run under presure but after the thermostat opens up there is usually some give in the hoses when you squeeze them. The car has thirty thousand miles on it and the hoses look almost new. The hose remains hard as a rock. I never had an engine that ran with that much pressure in the cooling system. I've been working on cars for fourty years and this is a new one for me. Is it possible they didn't bleed the system after they put in the new thermostat?Thanks

 

I don’t think it needs a bleeding, if it did you would have cavitation accompanied with not enough pressure.

 

On this vehicle the thermostat is not on the top of the engine and the hose remains hard while engine is hot...... The thermostat on this vehicle is on the bottom of the engine and the bottom hose regulates the thermostat.... Cars no longer have "overflow tanks" but it is called an expansion tank, and the flow of coolant runs backward from what we've always been used to.

 

I thought we was going forward. " the flow of coolant runs backward "????? i want to say something but that bends my mind way TO much. I WANT MY 66 Charger back, lest i can get chicks with it.