Wierd Low Oil Pressure

[94stangfan]

I have a 95 GT that just hit 100k miles. I noticed that it has good oil pressure when driving down the road and at idle. The weirdness hits when I pull up to a stoplight. The oil pressure drops down to the L and fluctuates down there. If I hit the gas, it goes back to normal.

I only have the factory gauge on it, so I can't tell actual numbers.

Does this sound like an oil pump going bad, or possibly a sending unit?

I forgot to mention, this only happens after the engine gets warmed up to normal operating temps. The needle will start to shake and eventually go down.

Thanks

 

[Bullitt95]

Replace the sending unit. It's a ~$10 part and that's likely to cure the problem.

 

[toyman]

The sending unit is a pressure sensitive switch with a 6 psi trigger. So where it reads on the gauge isn't important. However, if the needle falls to zero I would be concerned.

 

[94stangfan]

Changed oil

I had just bought the car, it was showing good oil pressure when I test drove it, but then it dropped to about the L on my way home at a stop light.

I checked the oil and it looked pretty dirty. I contacted the people I bought it from and they said they just had the oil changed at Wal-mart. Either they were lying or Wal-mart never changed it.

Regardless, I changed the oil and put some high milage 10w-30 in it and now I have good oil pressure.

No need to change the switch.

Thanks for the help,

Keith

 

[toyman]

You may or may not have good pressure. All you know for certain is the pressure is above 6 psi. The gauge position means nothing. It's either reading or it's not. Same as a bulb being either on or off.