Coolant coming out of timing cover bolts?
For a bolt hole that goes into a water jacket ?
Yes, it works on most leaks.
I was surprised at how well that it works.
The powder melts and when it gets to the leak, solidifies and stops it up.
I was once visiting my friend and some of his son's friends were over (about 18 y/o). One of his friends had a monte carlo ss and it had a chunk of gasket missing from the water pump. You could see the slow stream of coolant leaking out of it. Since I carried a tube with me for emergencies, I poured 1/4 - 1/2 of the bottle in his radiator and we ran the car for 40 minutes and the leak finally stopped. We just intended this to last to get him home until he could buy a gasket and change it. He ended up selling the car two weeks later and still hadn't changed the gasket as it was still holding. I couldn't believe that it worked on that bad of a leak.
I always use it after I replace a water pump bolt or end stud for the exhaust manifold and it seals the threads right up without any other type of sealant on the threads. I put them in dry. It finds the leaks in the threads and seals them right up.
