my 01 2.9 started making a hissing noise sounds like coming from top of cylinder thought at first coming from fan but continues when fan is off. I also saw 2 drops of antifreeze below water pump on skid plate but nothing on cylinder exaust seems ok no moisture. my question is if my water pump was going out could be making the noise. drained tranny oil doesnt appear to be milky but need to change oil on my other 01 and compare

You'd have to look further into the hissing noise to figure out where it's coming from. You could try torqueing the head.

There is an update for your waterpump...new seals and gear...maybe even the impeller, but I don't remember.

The problem caused leaking, but not necessarily into the motor, so you might not see coolant in your oil.

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