Using Dye to find Oil Leaks

[Richard M.]

Just another Info-Thread.........

After cleaning heavy oil from a engine, add a 1 oz bottle of this dye to the oil. (1 oz for V8's works fine)
http://www.napaonline.com/napa/en/p/BK_7652661

Run the engine for a while until hot, shut down, then using a "black-light" your leaks will jump out at you.


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[Patrick H.]

Re: Using Dye to find Oil Leaks

Nice! I always wondered if those kits worked.

[Tom L.]

Re: Using Dye to find Oil Leaks

That type of dye has been available in the refrigeration industry for MANY years. Don't think it matters to this discussion but compressor manufacturers will void a warranty if the dye is found in the oil. So here's my problem with this type of stuff. ANY leak will be seen with the light, ANY surface that comes into contact with the dye will be shown as a leak. For example, if you put the stuff in, let it circulate on ALL internal surfaces, accidentally touch a trace of oil with your hand and then touch other things all of those other things will show in the light. The leaks, true, or false just keep moving around and of course the inside of your engine. Cleaning the dye off or out is almost impossible. In other words, once you put the stuff in your engine there is NO turning back. Good luck if you try it. Just my humble opinion. Have fun!!

[Richard M.]

Re: Using Dye to find Oil Leaks

Tom, Interesting.

However I think the diagnostic results outweigh the inconvenience. I would imagine several oil changes will dilute the dye enough that eventually it will be dispersed. Even if it's still there later it is designed to be compatible with oil. What was very rewarding in this test, was that I had suspicions about the timing cover to harmonic balancer seal as a problem. Using a small mirror and the blacklight deep inside the finned balancer told me everything in there was sealed. Additionally, after I reseal the intake manifold, I can rerun the engine to test the new seals. After that I'll then change the oil. I find it a good tool to use for these pesky leak problems.

My first experience with this dye was many years ago on a Chris Craft antique boat. This model was a Capri, with a it's engine behind the bench seats under a hinged deck cover with very limited access. Much like this one....
1957-Chris-Craft-Capri-19_-pix-1sized.jpg
It had a continual leak which ended up at the bottom of the oil pan then into the bilge. This was a completely restored boat with a new bottom. The CC engine was original and rebuilt/restored.

After a engine pull to reseal the oil pan, it continued to leak after prolonged use. It drove us crazy. We finally cleaned it again and used the dye to help find the leak. We found it.....Unbelievably, the cast aluminum oil pan itself was the culprit. It was porous. We could see dye traces coming out of the pores on the bottom of the pan. Problem solved with a replacement, which we tested again with the dye with the engine on a test stand. Then we installed the engine back in the boat with confidence.

Rich