LOW OIL PRESSURE ALARM

[Salvador Alasco]

I just bought a 1996 TOYOTA CAMRY,Coupe with a rebuilt engine. Although it came with its initial jitters when I first drove it, the car was running fine until about one week ago,
I noticed that my “low oil pressure indicator” was “lit” but then I was just a few hundred feet from my home so I dismissed it as “one of those alarms” that would go away the next time I drove it again. I was wrong.
The next day, after driving the interstate for about 16 miles, I got off the exit ramp and the low pressure alarm came on and started to “flicker”. It was not ON all the time but came on-and-off while flickering. I reached my destination without the alarm.
When I drove home, and got off the interstate, the flickering indicator came on again.
The thing is, the alarm comes on whenever I slow down after a high speed run.
I already replaced the low pressure sending unit but that didn’t work out. A mechanic friend tested for the presence of a normal oil pressure and there was nothing wrong with the pressure.
What is wrong with my car ? What did I not do to correct this dangerous indication ? Can I do something to correct this or do I need a professional to look this over ? I am afraid to drive the car at this point.

Thanks,

Sal

Topic

[Frank Heiser]

Was the car hot when your friend checked the pressure? Classic sign of worn engine bearings is low oil pressure once warmed up. I’m no expert on Toyota but I had an old Ford F150 that had no issues while the revs were high (aka on the interstate) but once I slowed down the light would flicker or just stay on. Do you hear any noise coming from the top of the engine? Lots of times you’ll get tappet noises etc. because the heads are usually first to starve for oil.

Since you already replaced the sensor, I’m suspicious that it could be bearings or something along those lines. If you haven’t checked the pressure when it’s good and hot, I’d check that next and see if it’s still within spec.

If it really is low pressure there are some cheats that can give you some more life out of the engine, I started running 15W30 oil in my Ford and it kept the light away for a few thousand more miles. Thicker oil flows slower so the pressure can build up higher behind it.

BTW, of all the warning lights, the oil pressure one is the most critical, never ignore it! If there’s a real issue it can mean your engine will self-destruct in short order. When I was a kid my mother ignored an oil light, the car drove another mile and seized up the engine, ruining it. The oil change place didn’t tighten her drain plug and it fell out on our way, so it lost all its oil, we were half-way to Yellowstone park in the middle of nowhere!

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