The oil pan gasket can sometimes continue to leak even after you have replaced it. There are several reasons it can leak, but it needs to be repaired, no matter the reason. Not only can it lower the oil level and cause engine damage, but it can also lead to contaminants getting into the oil system. A few tips to get the oil pan to seal properly can alleviate this problem.
Using a torque wrench is the most important thing to remember. The oil pan bolts must have a certain amount of torque to make the gasket seal properly. Under-tightening can cause a poor seal, and over-tightening can split the gasket. A torque wrench has a knob at the base that can be set to certain torque specifications, which can be found in a repair manual specific to your vehicle.
Using room temperature vulcanizing (RTV) silicone helps maintain a good seal. This silicone is flexible without breaking its bond; therefore it will not begin leaking due to the movement of the engine. Placing a thin bead of this silicone on either side of the gasket will prevent leaks over time.
Foreign debris on either the oil pan or the engine block can break the seal of the gasket. To avoid this, use a razor scraper on the oil pan gasket and the engine block where the gasket sits. You can also use sandpaper on any burrs that the razor scraper cannot remove.
The pattern in which you torque the oil pan bolts can cause a leak. Many times, amateur mechanics will tighten the bolts in a straight line. What this does is causes one side of the pan to be tighter than its opposing side. This can cause a leak from the looser side. The way to avoid this is to tighten the bolts in a crisscross pattern. An example is if you tighten the left front bolt first, tighten the right rear bolt next. This ensures equal torque on both sides.
Another sealing problem is if the oil pan is damaged near the seal. If it is bent, some amateur mechanics will attempt to hammer it straight, but this does not always work. If it is dented, purchase a new or good used oil pan.
