93 Buick Regal 3.8 liter Oil Pressure?

[weekendmac]

I have a 93 Buick Regal with a 3.8 liter engine. Historically, the oil pressure on the dash has read in the 40 range. Recently with the last two oil changes, the gauge has shown a consistent pressure range on the gauge in the middle of the 40 and 120 readings, say 80.

Is this good or bad? What is normal? Should I pursue investigating the oil pressure related items? Your input is appreciated! Thank you.

[Master01]

I would say that the weights of the oil you are using are different. I had the same problem. Use 10w-30, eventhough it says to use 5w-30. Just to be safe talk to a mechanic and see what he thinks. Also check the connections to the oil pressure switch make sure that they are making a good connection.

[weekendmac]

Thanks for the note. I'll check the connections on the oil pressure switch to make sure the connections are good. I would assume that they are because the gauge does not show any eratic movements. In other words, it looks like it is showing a valid reading. There is a little movement with revs of the engine.

Sorry, I should have specified that the oil and filter being used have been consistent for the most part. Only one oil change was done by someone other than myself. I used 10w30, same brand, in all oil changes. Same brand with the filters as well.

Anyone with other ideas or suggestions? Is 40 the normal reading or is somewhere in between the 40 and 120 an acceptable reading?

[maxwedge]

Any pressure above 70 psi is too high, you should put a know good test pressure gage on the port at the oil pump housing and see what the "real" reading is, the dash gages can be very inaccurate.

[mtmaurer8ooo]

It's probably not the oil. 10w-30 and 5w-30 are the same 'weight' oil at operating temp....the only difference between them is when the engine is cold(5-30 is less viscous at colder temperatures and at start up). If oil were the culprit you would really only notice the difference when the engine was 'cold'. It sounds to me like someone may have gotten a bit overzealous and damaged the oil sending unit as Master01 alluded to, or the sender may be just be going bad - parts do wear out. A bad sending unit will usually cause a 'spiked' gauge more than erratic movement. If memory serves, it is quite easy to do on those particular engines. I would have the servicing shop look at it, and get a second opinion from a reputable mechanic. Of course, this is past the fact that there may be something else going on there, so I would have the oil pressure checked by the same mech. as the previous poster suggested, and you may indeed may just simply have a bad dash gauge. Good luck. Let us know what you find. M.

[conegito]

I have a similar problem with my buick regal 3.8 oil pressure.
Can you tell me where on the engine is the oil pressure switch?
Have been trying to get the location but no one knows.

Thanks,
Conegito

[HotZ28]

The sending unit is located in front of engine and above oil filter. In addition, please avoid posting or voting in outdated threads. It merely clutters up the message board and makes it more difficult for fellow members to sort through the vast amount of information contained on the boards.