Ideas to Stop an Oil Leak

As an engine gets old, oil leaks can be expected. The main causes of oil leaks are the loosening of bolts and the wearing of gaskets, which are usually not too difficult to repair. The real challenge is figuring out exactly where the oil leak is coming from.

Start with a Clean Engine

Before you tackle the project of making your engine leak-free, it's a good idea to start with a clean engine. Use a foaming engine cleaner to get as much oil as you can off of your engine. Raise the front of your car on jack stands and clean the bottom of the engine as well. Cleaning the bottom of your engine will be more important than the top when trying to trace an oil leak. Usually, cleaning an engine is fairly simple: Just warm up your engine slightly, cover all electrical accessories and the carburetor or throttle body and coat all of the surfaces with foaming engine cleaner. Let the cleaner sit and emulsify for a few minutes before hosing everything off.

Getting the Leaks Going

Once you have a squeaky-clean engine, it's time to find out where your oil leak is coming from. Take your car out for a short drive on a clean road. Drive long enough for your engine to completely warm up and go through its normal pace of driving rpms before heading home and parking on clean asphalt of concrete. Do not park on old oil stains.

Tracing the Leaks

Once home, get your car back up on jack stands and try to find any leaks that may have started during your drive. Using a flashlight, examine all mating surfaces in which oil may leak from. Some key areas to inspect are around the edge of the oil pan, around the timing cover, the bottoms of valve covers, around the oil filter, around the distributor and the edges of the intake manifold. Look for wet areas and follow drips from the bottom of the engine up to their source.

Stopping the Leaks

Once you figure out where the oil is coming from, it is much easier to stop the leak. The first thing to try is to tighten the nuts or bolts that hold the two mating surfaces together. Use a torque wrench if you can and torque the questionable nuts or bolts to factory specifications. After doing this, clean your engine again and go for another drive. If the leak persists, you will have to replace the gasket where the surfaces meet. Use a high-quality gasket and sealer.

Replace the PCV Valve

A properly working PCV valve keeps the internal pressure inside your engine under control. If you have a clogged PCV valve, pressure may build up inside your crankcase and cause oil to blow out through the gasket surfaces. To test if your PCV valve needs to be replaced, pull it out of the valve cover and shake it. If you can hear a rattling, the valve is good. If not, replace it.

"Stop Leak" Products

Any mechanic worth his salt will tell you that "in-a-can" products that advertise the ability to stop oil leaks are dangerous and not worth the money. Pouring a product that is designed to stop leaks may also clog small oil passages that keep vital engine parts lubricated. Do not use these products.