Pepper in the radiator

I read recently about pouring a can of pepper into the radiator can stop a minor leak without damaging anything. Just wondered how much truth and/or danger there was to this before I try it out on my Taurus SHO.

I keep a can of black pepper in the garage as a stop-leak. Works as good as anything you can buy. However, you don’t need to pour the entire can into the radiator. A tablespoon usually does the trick.


Your cooling system is so important to the engine that I would rather fix the cooling system properly than take a chance of overheating the engine. Pay a little now or pay a lot more later. The choice is yours.

I don’t know about pepper, but I was surprised to find out that the story I had heard about Bars stop leak being used successfully to repair a cooling system leak on the US Nautilus is actually true. If I need to use something, that will be high on my list.

"En route to the polar ice cap, the engineering crew discovered that a small salt-water leak had developed on one of the nuclear reactor steam condensers. The leak was spilling sea water onto a critical piece of machinery, causing noxious fumes to fill the Engine and Maneuvering Rooms. A submarine is a labyrinth of tubes and pipes, so pinpointing the leak while at sea would have been impossible. Something had to be done.

In Seattle, the sub?s last port before embarking north, the commander had an idea to save the mission: He sent his men out to buy as much Bar?s Leaks as they could find. Dressed in civilian clothes, the crew covertly spread out over Seattle to purchase the legendary stop-leak solution.
With the Bar?s Leaks safely on board, sailors poured 70 quarts of it into the submarine?s condenser system.

It worked! With the leak stopped, the USS Nautilus was able to complete its top-secret mission, becoming the first submarine to cross the North Pole underneath the Arctic ice cap."

I confirm the story about the USS Nautilus (at least it appears in print) I read the story in a issue of Naval History (great magazine) I know I have the issue somewhere but I can’t find it. It was a story about the first underice transit of the North Pole,every bit as important a event as Sputnick (probably more significant in the military sense).The transit didn’t happen the first time,they turned back twice before sucess.

Truely a testament to our troops’ ability to innovate to complete the mission.

I’d still rather avoid fixing my car with it. I’d still prefer a proper fix.

Black pepper does work. As Tester mentioned, you only need a tablespoon’s worth.

Bar’s Leak is a slightly different animal. Too much of Bar’s Leak can cause radiator tubes to get clogged. I had this problem, and used the Bar’s Leak when the pepper stopped working. It stopped the leak for a month or so, but blocked up tubes in the radiator, and I had overheating problems next. It all came together when the overheating stressed the already-weakened headgasket, and finished it off. I had the radiator checked since it was out, and flow was reduced to 40% normal. Had to buy a new one. The ultrasonic bath could not clear it.

It will work but if it were me, I’d consider it a temporary fix and buy a new radiator because they’re not that expensive.

Keep in mind that if the leak is in the plastic tank of a radiator it’s entirely possible that tiny sealed leak could instantly become a long, gaping crack. Plastic can work great until it gets some age and heating/cooling cycles on it.

You can probably get a brand new radiator for about a 100-125 bucks. Compare that to the cost of an SHO engine.