I was just wondering what the oil and battery gauge were supposed to read? And what do the numbers indicate on the respective gauges? :confused: Curious because my oil gauge seems to be bouncing around while I'm driving.

My oil gauge did that, and eventually stopped working.

It turned out being a bad sending unit.

They don't last forever.

The battery gauge should read somewhere between 13 1/2 volts and 15 volts when running at speed. Possibly a little less when idling

What about the oil gauge? What exactly do the numbers mean?


My oil gauge did that, and eventually stopped working.

It turned out being a bad sending unit.

They don't last forever.

The battery gauge should read somewhere between 13 1/2 volts and 15 volts when running at speed. Possibly a little less when idling

I'm in Canada, so mine is metric, so someone else will have to answer that one

the oil gauge reads oil pressure in psi pounds per square inch if it bounces around a lot I would say that sounds like a sending unit. sitting at idle it should probably read at around 45 or so if it is a 4.3 I would just look for a loose connection then if none was found just replace it, I want to say it is tight next to the oil filter and is easy to change but I am not positive

the sending unit isn't an 'easy to see' part, if its starting to malfunction, its fine, and as long as you dont hear a 'tick' at anytime, the pump is fine and the unit is bad... the battery light isn't very accurate, it is ten years old (almost 11 wow) afterall, my bird reads 12 ish, but the voltmeater at idel off the alternater tells me 14.9... as long as you dont crank slow, your ok... how old is your battery and what kind is it?

My Blazers is the origional volt meter, and still accurate.
I must be lucky from the sounds of it.

I was just wondering what the oil and battery gauge were supposed to read? And what do the numbers indicate on the respective gauges? :confused: Curious because my oil gauge seems to be bouncing around while I'm driving.

Oil Pressure Gauge: reads oil pressure in pounds per square inch (PSI). The sender is usually located on the oil filter mount; I belive the pressure is read after the filter. It is normal for the oil pressure to fluctuate. When the engine is cold and it is very cold outside, it's not abnormal to have the gauge peg on the high end. Once the oil is warmed to normal operating tempurature, pressure will fluctuate slowly from the idle reading to the normal road speed reading (obviously in conjunction with what your doing).

Volt Meter: With the engine off, the guage will read the battery voltage (typically 12v) when the key is turned to "on" or "accessory" positions. When the engine is running, the guage will read a higher voltage; this is the charging voltage being applied by the alternator. You should always have more than a 12v indication when the engine is running (typically 13-14v); 12v or less means your battery is being discharged and anything much higher than 14v could indicate a bad voltage regulator. You might see some small fluctuations as big draw accessories are initially turned on (A/C compressor clutch, headlights, etc) and you'll see a bit of a spike after the starter disengages (a rapid initial charge voltage).

Your bouncing oil pressure gauge may be the sender unit or it might be a loose/bad connection to the sender or a ground.


mike