John Deere Maintenance Monday: Oil pressure warning light

In this edition of Maintenance Monday, we're answering a question from Scott in Texas. The oil pressure warning light on his tractor goes on and off. He checked the oil level and it's fine. What else might be causing the light to come on?

Allen Drake is a John Deere tech instructor at Lake Land Community College in Illinois. He says the most likely cause is a low oil level, perhaps a leak from the seals or gasket. There could also be a plugged filter. But, the light might be an alert of something more serious, such as worn bearings, crankshaft, or oil pump.

"The first thing I would do is check the oil level. If the oil level is correct, then I would use a different gauge to verify that there is a problem," says Drake. "If I see that there is a problem, if my gauge agrees with the warning system on the tractor, then I would probably want to disassemble the engine and start looking for wear in parts."

It's possible that a light that goes on and off could be caused by a weak or failing oil pressure sending unit, which is also called an oil pressure switch. Drake says the engine should not be operated once the light comes on because it can quickly become serious.

"If you continue to run it with an oil pressure light on, first we need to think the oil pressure is responsible for keeping metal parts separated," says Drake. "The oil pressure keeps an oil film between rotating parts. If there's no oil pressure, the oil film will be removed and then you have metal-on-metal contact which can be very expensive damage."

To avoid risking damage, Drake says call your dealer immediately.