Leaking oil pan gasket — Seal versus Replace

You can seal a leaking oil pan gasket without removing the oil pan

Replacing a leaking oil pan gasket can be an expensive repair costing almost $1,000 for some engines. Many DIYers want to know if they can seal an oil pan gasket with RTV or some other sealant. The answer is, sometimes. But only if you do it properly

Which leaking oil pan gaskets can be fixed using RTV?

Older engines with neoprene or composite (cork and neoprene) oil pan gaskets can sometimes be fixed using RTV. However, the proper preparation is critical since RTV won’t stick to oily surfaces.

However, if your oil pan was installed without a gasket and just uses RTV, you can’t use RTV to patch it. Why? Because RTV doesn’t stick to RTV. The only fix is to remove the oil pan and remove all traces of the old RTV before you can install new RTV.

Preparation steps before applying RTV to the gasket

• Drain the oil
• Using aerosol brake cleaner, clean off exterior of the oil pan
• Inject aerosol brake cleaner into the breach of the leaking gasket. Allow the brake cleaner to drip out of the oil pan drain plug. The goal is to get a clean dry surface on the existing gasket for the RTV to cling to. Let all the solvent evaporate. Use compressed air if you have it.
• Inject fast curing RTV (Permatex The Right Stuff) into the breach in the oil pan gasket and to the recently cleaned exterior surface of the oil pan surrounding the gasket.

Which gaskets can’t be fixed using RTV?

Silicone gasket leaks cannot be fixed with RTV. The RTV will not stick to the silicone

RTV sealant leaks cannot be fixed with more RTV. New RTV will not stick to old RTV

Leaking pan gasket

Can you seal an oil pan leak with a leak sealer or stop leak product?

Oil leak sealers and stop leak products work by softening and swelling rubber gaskets. Most oil pan gaskets are silicone, a combination of cork and neoprene, or just RTV and no gasket at all.

There are very few neoprene only oil pan gaskets. However, if your engine has one, you can try using an oil stop leak product.

But here’s warning about using an oil stop leak product: All oil stop leak products affects all the rubber gaskets throughout the entire engine, not just the oil pan gasket. If you decide to use a leak sealer product, follow the directions to the letter; more is NOT better. Using too much leak sealer can cause all the rubber gaskets to swell to the point where you actually create more leaks.

©, 2023 Rick Muscoplat