Anybody know of a way to detect coolant in motor oil? I've heard of a product that can be added that will show the presence of coolant under a black light. And is this something I can do myself?

Anybody know of a way to detect coolant in motor oil? I've heard of a product that can be added that will show the presence of coolant under a black light. And is this something I can do myself?

The products that show coolant leaks with a UV light are good for detecting external leaks like around the intake manifold, heads and other parts of the engine/cooling system. The proper way to detect coolant in motor oil is by running an oil sample analysis. Also you can check the condition of the motor oil visually. Look for the oil looking milky and the oil level may increase so check the dipstick level reading.

The lower intake manifold (LIM) gaskets are a possibility if not upgraded to the improved gaskets. A very common problem on the 3.4L including the 2002 model year. A GM TSB has been out on the LIM problem for quite a few years now.

Pull the drain plug afer it has sit overnight.
Any coolant in the oil will be under the oil and run out the hole first.
Or take a oil sample and have it tested.
If the oil turns milkey you know for sure you have coolant in it.
MT