ZX-Tex

iTrader: (15)

So I am trying to trace down a slow coolant leak on this LS-1 Miata of mine. I am pretty sure it is in the radiator. But to be sure, I am doing the UV coolant dye trick.

For those who do not know, one can get a dye you put in your coolant that glows very brightly in UV light a.k.a. a 'blacklight'. You put some in your radiator, run the engine for awhile, and look for leaks with a UV light. Works great. FYI I bought the dye at the auto parts store, and the UV light at home depot. It is a compact fluorescent type bulb.

I had a serious "oh-****" moment tonight when looking around the engine in the dark with the UV light. I noticed that a small amount of oil residue around the oil filter had a slight glow to it, the same yellowish color as the radiator dye. So, even though I had seen no other evidence of coolant in the oil (milky oil, water bubbles in the oil, rising oil level, etc) I immediately start having horrid thoughts of a blown head gasket. That is, coolant has UV dye, coolant gets in to oil, oil glows.

So I check the dipstick with the UV light, and sure enough, the oil on the dipstick has the same yellowish glow. Damn it...

After hating life for a few minutes, I decide, just for grins, to see if the Rotella-T synth I have in the engine right now glows on its own. So I grab a bottle of the same Rotella-T I had put in the engine at the last oil change. There is about a quart of clean, unused oil left in it. I poured a little in the cap, and sure enough, it glowed in the UV light, the same yellowish color. A small drip of the same new Rotella that I splashed on a non-glowing surface also fluoresced yellow. I then held the capful of the Rotella and the dipstick up next to each other in the UV light, and they had the same glow to them. Same color, same brightness.

Whew... life is OK again.

So, I have no idea if this works with other oils, or what the additive is in the oil that causes this glow, but there it is. Rotella-T synth glows slightly in UV light. It is not nearly as bright as the coolant dye, but it is visible. A quick Google search makes me think it is the detergent in the oil that is glowing since some detergents fluoresce in UV. I also saw a writeup from a dry cleaner talking about using UV light to identify an oil stain on fabric.

ZX-Tex

iTrader: (15)

So being the dork that I am, I decided to investigate further with a few lubricants sitting around the garage.
- Valvoline 80-90wt synthetic blend gear oil glows bright yellow big time, almost as much as the coolant dye.
- Mobil 1 synthetic ATF does not glow much at all, maybe a tad yellow.

y8s

iTrader: (8)

it's probably the phosphorus in those oils

ZX-Tex

iTrader: (15)

Could be.

hustler

iTrader: (6)

T6 formula?

Fidgitk

iTrader: (3)

Lots of oils fluoresce, put a potato chip under the same UV light and it'll glow the same color. It has nothing to do with the phosphorus. In fact when prospecting for oil one of the tests done on core samples is to look at them under UV. Crude oil glows a blue color, refined oils a pale green color.

Eadohcturbo

Motor Oil contains fused ring molecules or PAHs which cause it to glow.

Travisivart190

iTrader: (1)

Next time I want to go to a rave, I'll change my oil before, bathe in the used T Synth, and go rub on some ladies. They'll all be begging for my oil.

NA6C-Guy

iTrader: (1)

Skin cancer is awesome!

Travisivart190

iTrader: (1)

So are ladies begging for you to put oil all over their body. Maybe even their face. I think it's a give and take situation. With me mostly doing the taking. And giving some oil.

ZX-Tex

iTrader: (15)

I spoke with a Scientist I work with about this. He used to be in the petrochemical business. He said it is probably the phosphorus, especially since the gear oil fluoresced more than the motor oil.

You know, I went to a strip club once where they used blacklights and multicolored UV glowing oils on the dancers. That was pretty cool. Yes they were female.

Cococarbine3

iTrader: (1)

Concentrated laundry detergent fluoresces as well. It was embarrassing to go lazer tagging, and then have white blotches showing up all over my seemingly clean clothing. Especially in the crotch area.