Yellow Gunk on Alternator

[XRL]

So when I was changing my oil yesterday, I noticed some yellow gunk on the bottom of what I believe is the alternator. A quick google search had some people talking about it possibly being coolant. This is a possibility, as I know I've got some sort of slow leak around the water pump, which is to be expected at right near 100k. But there's only one issue, my Vue has Dexcool in it, which is red, not yellow.

Any ideas? Is this normal? I haven't noticed any issues from this yet, but I'd like to take care of this before anything bad happens.

As an aside, shortly before my Explorer died, it exploded similar yellow gunk inside the engine bay. So I'm a little unnerved. My explorer's alternator was shot though. My Vue, not so much, though it could use a new battery soon.

[far2grumpy]

I've attached a PP illustration lifted from FSM.

The alternator is on left-end of engine - side nearest radiator - and is the upper of the two belt-driven devices to the left of the catalytic converter.

The item underneath the alternator is the A/C compressor. If the gunk is on the bottom of compressor it could be residue from leak-detector chemicals and might not be that unusual.

[XRL]

Looking around, I found a picture from nitroussaturn's timing belt replacement writeup that illustrates it perfectly. My Vue has this same yellow gunk. Someone mentioned it being Freon on a condenser.



I'm guessing it isn't anything to worry about.

[fdryer]

far2g has it right, refrigerant dye used for leak detection. Far be it for me to be the messenger of bad news but that picture showing oil collecting on the bottom of the a/c compressor is refrigerant oil that isn't supposed to be there, along with dye. It means a leak has been occurring and most likely around the compressor front seal, behind the clutch pulley or from the case cover. Various dye colors have been used over the years and green or yellow seems to be the color of choice. An easy test for this is simply borrow a black light or uv light and shine it at the green/yellow stain; if it glows (especially at night) its dye from a refrigerant leak.