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Finding an anti-freeze leak

The wife’s got a 2002 Chevy Venture with 85k. She’s leaking anti-freeze from somewhere. The tank was low and I found a small puddle underneath her spot in the garage. How do I find the leak? I did a quick check tonight (It was getting dark) and couldn’t see anything obvious around the expansion tank or associated hoses. It has DexCool. Does DexCool crust up and get very noticeable like Green does when it leaks? I really don’t want to crawl under there.

I really don’t want to crawl under there.

That is why you pay a mechanic to do it. The only way you are going to find it is to get out and get under.

i have found the best way to find a leak IS at night. a flashlight will show the green drips glowing back at you.

find the water pump. if it is visible look around under and near for evidence of leaks.

if your pump is under the timing belt cover look around the large crank pulley for drips too.

if you cant find a leak you may just have to resort to going to a mechanic.

You might be faced with an intake manifold gasket leak. Which is a common problem on the GM V6/8 engines. You need to have the cooling system pressure tested to determine where the leak is located. Also, keep an eye on the oil condition. When these gaskets leak, coolant can end up in the oil pan with the oil. And if this continues long enough it can destroy the engine.


How can you tell if there’s coolant in the oil? Do they mix completely or is there a coolant slick?

If coolant is getting in the oil, the oil level will rise. Also, the oil will have the appearance of a brown/sludgy substance. It’s uaually at this point where engine damage has occured.


Iam pretty sure the green coolant will floures (glow) under UV light. Now orange DexCool have to try it

Buy a blood light at Wal Mart. They are in the hunting section, usually made by Winchester or Remmington. They are marketed for tracking deer blood trails. Sometimes they are called a tracking light. They have black light led’s that make florescent stuff glow. It that doesn’t work, you should be able to get a bottle of florescent dye from the parts store. Pour it in the radiator and check around again with the light.