Weird Oil Pressure Reading

[nivit0]

Last week, I bought a 1997 Firebird. All week, I've been doing the maintenance it needed, but I noticed something weird within a day or so of changing my oil and filter. The oil pressure gauge in the dash reads higher now, always staying above the midway mark, and creeping to 3/4 under acceleration. I used a premium filter, but only (cheap) Citgo oil. Could the reading be high because I didn't use a top grade of oil, or could the gauge just be reading artifically high for some other reason? Also, can someone please tell me where to find my fuel filter? The previous owner had installed some great looking ground effects, but it's hard to get under the car to look around, and the Hayne's repair manual doesn't tell me where to look. Thanks all

[speedy-v6-camaro]

As for the fuel filter....its located under the drivers side about 1 ft in from the outside of the car and about 2 ft in front of the rear tire. I just changed my oil to a high performance filter and red line synthetic 5W30 and noticed my oil pressure seems to be higher too. As to why...I have no idea.

[nivit0]

I appreciate the info on the filter location, I'll make sure to get that changed tomorrow when I have the car up on ramps. Glad to hear I'm not the only one with a wacky oil pressure gauge, let's just wait and hear from the rest of the community as to the reason.

[Alexcab7]

My oil pressure gage goes from the 3/4 mark to the 1/4 mark I am not exactly sure if it is just not a good gauge or what. My pressure is usually higher when I have just changed the oil. The weird thing is when I accelerate it goes up to the 3/4 mark and usually stays around there and when I brake it goes down to the 1/4 mark, im not sure why it does that.

[need4speed]

if you think your oil pressure guage is wacky...after my oil is warmed up and engine is idleing, oil pressure is normal, but start driving and get above 2k rpm, the guage flies over to the right and max's out. It's pegged the entire time when I first start it up when it's cold. Just started doing this last week and I changed the oil 2 weeks ago. I'm not sure why it's doing this but I'm guessing sending unit and I have no idea how to get started on fixing it.

[ March 22, 2003: Message edited by: need4speed ]</p>

[nivit0]

Alright, the oil pressure sending unit might be suspect. Where on the engine is it, and is there a procedure to clean or calibrate it? Is this the kind of thing where just disconnecting the battery will fix upon reset?

[RedCamaro]

the sending unit is in front of the engine left hand side down close to the bottom...got a wire harness plug to it....that gives your gauge its readings..if you unplug it it will read max out or no pressure at all.

[Christian]

Yea it's not hard to find, the sensor that is. It sticks out right from the engine @ the bottom. Mine cracked about a year ago and I fixed it in about 15 mins. When it starts going bad it will 1. send crazy fuggin' readings 2. Start leaking oil and the pressure will be low 3. Start smelling like something is melting bcuz it is being scalded by the oil. Why do all of the dash readings in our cars blow rectum, I love mine but damn!!! [img]graemlins/rofl.gif[/img]

[ March 23, 2003: Message edited by: Christian ]

[ March 23, 2003: Message edited by: Christian ]</p>

[whtefbrd96]

actually i think atleast MY gauge is close to being acurate whenever i put fresh oil in my oil pressure is at 60 psi at idle and up to 80-90 running when it is getting close to time for an oil change it will read 40 -50 under idle and 60 running. i wouldnt worry too much about higher oil pressure as i would lower oil pressure as in below the first mark.

[nivit0]

That makes sense. I only noticed the change in range reading, but I assumed my old readings were accurate. The oil I pulled out of that car was pretty dirty, and might have been giving a falsely low reading. The relatively higher reading I'm getting now is probably the accurate one, I just wasn't sure what's normal for this car. My new readings are a bit below the mid point (60) mark at idle, and they rise by a quarter of the range under acceleration. Thanks for your help.

[strobhen]

I would not be concerned about minor variations in oil pressure when you switch oil brands.

Especially if you switch oil types.

Generally non-synthetics will give higher pressure readings than synthetics (synthetics are inherently thinner).

Now if it is maxing out or zero'ing out, I would be concerned. Mine is starting to act wierd as well. I think its probably time to replace it.

[TheV6Bird]

<blockquote>quote:</font><hr>Originally posted by Alexcab7:
The weird thing is when I accelerate it goes up to the 3/4 mark and usually stays around there and when I brake it goes down to the 1/4 mark, im not sure why it does that.<hr></blockquote>Our oil pumps are mechanically driven. The faster the engine spins, the faster the oil pump spins. Mine does that to; when I am at idle, the guage reads lower (sometimes almost near the red 0 mark after I've been driving for a LONG time), but when I step on the gas, it goes back to normal.

[Dominic]

My 2002 is the same way. I idle above the middle 60psi mark and run ~75/80psi on the highway. Its fine [img]smile.gif[/img]

[Takumi Fujiwara]

I use the oil gauge as a way to set myself on a launch when dragin if Im just going for a normal start, I just get it up to normal running pressure, cause mine falls below the mid line when idle of course. But the higher pressure with a perfomance filter would make sense cause ur getting better flow.

[merlinsrealm]

lets all remember that the factory gauges are electric and from experience are never truly accurate. and if the sending unit gets hotter or colder than usual because of for example weather will change the gauge reading as well.