I just did a pressure check on the cooling system on my 04 6 liter. It reached 16lbs towing an enclosed trailer and into a strong head wind. I was just wondering what's the Normal pressure suppose to be, or is there a Normal pressure. I'm using the new style cap with the larger spring in it and it didn't kick any coolant out.


Thanks for the help

 

What level is your coolant at in the degas bottle when cold, and what temperature was your coolant at when you hit 16 psi?

 

its just above the min level.

 

And the temp there are a lot of factors involved there is no real average temp/pressure for every system. 3 to 5 psi is considered by many but like I say a lot of factors involved.

 

I hook the scan gauge up and check the coolant temp.

 

The harder the engine works and the more heat it creates the higher the coolant pressure.

3-5 psi is a good rule of thumb for simple driving conditions, ECT 190-198 or so.

Working it hard will see higher pressures, over 200 ECT under load it isn't unreasonable to see 8-12 psi.

Over 12-14 psi is an indication of an issue IMHO.

Josh

 

I plan on taking the truck cross country in a month so I figured I better check a few things, I'm doing a coolant flush and thermostat change shortly. Then I'll use the scan gauge at the same time as when I'm doing the pressure recheck. May even try a different gauge, just to verify that its working properly.

 

Just did another test drive, reached 15 psi and 200 coolant temp.

 

Does it spike up or just gradually rise?

 

goes up slowly

 

Is there a bunch of mud or crap in between the radiator and innercooler? Is 200 ect unloaded just cruising?

 

No mud or crap obstructing the air flow. That's towing my enclosed trailer. It runs about 9 psi 184 coolant temp not towing and just driving.

 

I've seen closer to 18 psi when i was hammering on my truck, but im tuned to the max.

 

this truck is bone stock, except for the blue spring. about 160,00 miles.

 

Head Gasket Issue?
After your truck is up to temperature and the pressure is up ,carefully vent the coolant pressure. Then drive your truck hard, you should be at or around zero. If your pressure rises you may have a bad head gasket. I see up to 16-18 psi, but im using extreme tuning. You could pressurize the system cold and it should hold 15 pi for at least 1 minute.