4.0 with Factory Supercharger has small coolant leak. Need help with Diagnostics

Second gen 4.0 with factory super charger. Trying to figure out small coolant leak. Dealer did pressure test and did not find any issues. I am getting a small amount of coolant being spun up on pulley. No overheating, and a very small loss of coolant. Only happens occasionally during long drive. So maybe a high rev or altitude(driving in Colorado High Country) induced moment. Has anyone else had this issue?

 

Curious what you find out. I've been experiencing a similar coolant leak (non supercharged though). I just ordered some leak dye for the coolant, hopefully that pin points it.

how many miles are on the coolant hoses? Mine are all original at almost 200K, so it could be just about any of them for me.

 

Id check those fittings below/behind the throttle body that run out of the thermostat housing. It looks to me like something’s dripping onto the belt and being carried around onto the oil filter. There are quite a few connections back there that could be suspect

 

buy a pressure tester & leave it under pressure overnight....
From your description, my guess would be water pump shaft area....

You dont just want to roll the dice off of what someone suggests here in regards to what the leak could be....

Pressure test overnight & get under it with a flashlight & try to isolate a leak...
Dont worry about diagnosing the pressure drop on the gauge, pressure testers can leak down as theyre not 100% sealed long term....
Just try to isolate the leak.

 

Probably water pump. That's the cooling system component that interacts with the drive belt..

 

You have two divorced cooling loops with the S/C, so a pressure test on one or both was conducted? It does appear to be inline with the water pump and throttle body being slung by the belt.

 

My water pump had a tiny leak from the weap hole didn’t notice it until I saw some pink crust around it ,I lost a very small amount of coolant between oil changes I thought it may have been evaporation,but since I replaced it I has not done that