Hi im having an over heating problem while im sitting in traffic for any period of time as well as sitting in my yard just idling, but when traveling its fine, i was thinking of the fan clutch but when i trying to stop the fan when running, its not that, so now im leaning toward a thermostat, also ive added water to it for the last 2 days i see no water leaks and the system is still under pressure when i take the fill cover off the reservoir, but all the water is gone, i have not seen any white smoke out the exhaust. any ideas will be helpful. its a 6.0 bulletproofed and egr deleted. i will also do a radiator flush and pressure wash the fins on the radiator in case some of them have dirt blocking air flow.

thx in advance.

 

I would NEVER have tried to stop the fan with the engine running unless you want a bent fan blade or worse..That proved nothing. Generally if the engine runs hot during idling and slow speed operation, I look for an air flow issue.I still suspect the fan clutch but could be a missing fan shroud, damaged or plugged radiator or condenser fins. A water flow issue will cause a hot running engine at highway speeds. I would also look for the source of the water leak by pressure testing the cooling system. Take a close look at the weep hole for coolant on the underside of the water pump.

 

thx i didnt know about the weep hole ill check it out.

 

Could cause your coolant loss as well as a loose hose clamp but unless you are losing a lot of coolant, that alone will not cause your overheating.

 

would the water ive been adding evaporate because its water and not coolant? when i remove the fill tank on the firewall its always empty but it has pressure as im turning the cap to take it off even if truck hasnt been ran for a day. is this normal? wouldnt that be an indication of not having a water leak? today ill get under the truck to check the weep hole, would it be best to have it running when checking it?

 

First are we sure it is pressure or possibly vacuum ?
When the engine cools down a correctly functioning radiator cap will allow liquid from the recovery bottle to go back into the radiator.
Weep holes can leak when the temp drops down and everything contracts, OR can leak when cooling system pressure increases as temp rises . The fan may speed up the evaporation so a leak may not be apparent..

The better way to verify any leak in the system is to use a cooling system pressure tester pumped up to the pressure shown on the radiator cap and observe if the pressure drops. If it does, then the source has to be found. As stated earlier a hose clamp may need to be tightened some if found to be a source of the leak Best to check and see what result you get pressure testing before suggesting anything at this time.

 

Thanks Hanky, can i put up the pressure tester at auto parts store?

 

Some stores will rent them. I don't know which ones..

 

Autozone rents them, I have rented two different ones for different vehicles and both were in very bad shape and did not work as designed, if you work on your own cars it might be worth buying a midlevel pressure tester set, I wouldn't buy a harbor freight grade set though.

 

An easy way to pressure test the 6.0L system is to "tee" in a Schrader valve into one of the vapor hoses that feed the degas bottle. With that fitting, you can put air pressure on it like you are airing up a tire, and you can use a stick gauge to check the pressure - just get a 0-20 psi gauge. You really want to put only 12-15 psi on the system.
three small pieces of hose the same size as your hose to the degas bottle (3/8 I would think)
two male-to-male barb hose adapters
one all male barb hose tee
https://www.summitracing.com/search/...chrader-valves