Questions regarding Oil Pressure (PICS)

[ImJJames]

I am little worried about my Oil Pressure, its readings seem to be abnormally low.

Here are some pics while road driving.


Here it is running at around 1,500 RPM (Going about 30-40mph)




Here I a at a stop light.


I just replaced oil yesterday, 10w30.

What kind of issues am I looking at? Thanks

[Madcarpenter]

Is your engine making any unusual ticking sounds when the gauge is reading that low at hot idle?

How does the oil look on your dipstick? Clear/amber, or cloudy/milkshake? Do you know if your upper intake manifold has been replaced yet? How about the lower intake manifold gaskets?

What brand filter did you install when you changed your oil? (Hopefully not a Fram, as they are now regarded as junk, and can sometimes even disintegrate and clog oil passages in your engine.)

You can't necessarily trust your dash gauge's reading as the true measure of your oil pressure. Cheapo aftermarket oil pressure sending units have been known to be less accurate than a more expensive Delco version. There's a decent chance that somebody at some time replaced the one on your rig by now...

If you use the 'Search' function here to look up oil pressure issues, you'll read the following recommendations made repeatedly by other Bonneville enthusiasts with a lot more experience than myself:

* Use a good oil filter. (Purolator Purone, Napa Gold, Wix, Mobil1... NOT Fram.)

* Consider replacing your current oil pressure sending unit with an OEM AC Delco unit.

* Buy, borrow or rent a mechanical oil pressure gauge, and screw it into the hole where your sending unit goes. Take pressure readings when the engine is good and warm.

* 25 psi at hot idle, and 35 psi at 1500 rpms can be considered low, but acceptable.


I noticed your temp gauge indicated just 150 degrees in those pics. HOT idle would be closer to 200, and oil pressure typically drops with increased temps as. Does your 'check gauges' warning 'ding' for low oil pressure when you're stuck in traffic after driving a while?



I'm right in the middle of the same issue, but my dash gauge reads about 5-7 psi higher than yours under similar conditions. Motor sounds great at 110k original miles. (I'm using a Napa Platinum filter, and 10w-30 Castrol high mileage.) I just purchased a Delco pressure sending unit, and am going to install it at my next oil change, as it's easier to access with the oil filter removed.

[Joshuabonnie]

That does seem low did you check to make sure that the filter is seated and you have no leaks. I would double check the connection on oil pressure sensor!

[MattStrike]

If the oil pressure is actually that low, it means a lot of bearing wear or failure immenent. Definitely verify that pressure with a mechanical gauge. With any luck, it's a bad sensor.

[myfirstbonnie]

[ImJJames]

Madcarpenter,

Engine does not make any sound when gauge is reading low. Sounds the same all the time. (Sounds good)

Oil is clear normal looking. I have no idea if intake manifold has been replaced.

I went to a local oil change shop, so I have no idea what type of filter they used, and to be honest I dont even know if they replaced it.

Lastly, check warning gauge for oil pressure does not come on when it hits a low oil pressure.

Joshuabonnie,

Ok, I will check.

Mattstrike,

I hope that is not the case, the engine has never dinged or made any kind of noise.

[Madcarpenter]

ImJJames:

OK, not to bum you out, but you really need to go to the 'Techinfo' section of this site, and read the articles about 'Dexcool' antifreeze, and 'UIM' (Upper Intake Manifold) and 'LIM' (Lower Intake Manifold) gasket failures. The 3800 engine is legendarily reliable, but some of them have an 'Achilles Heel', and this is it.

Since your SE is a 1996, these issues will very likely be relevant to your engine's health.

There are many experienced Bonneville owners and mechanics here at this club who can offer insight into your car's symptoms, but you first need to inform yourself about the 'care and feeding' of your vehicle, and especially those three issues in regards to your particular generation of Bonnie.

I've been reading this site nonstop for two weeks since I picked up a '95 SE for my wife. There's a wealth of knowledge and good advice available in this club.

[Mad Myche]

For the most part quick lubes are fairly honest on doing what they said they did for the oil changes, and unless they are spinning penzoil filters on then most likely you got a filter produced by Champion Labs; and they are a reputable manufacturers.

[yonkerse]

I would suspect a failing Oil Pressure Switch/Sending Unit. My brothers 05 SLE was reading similar oil pressures when we picked it up. Similar to you, the engine runs great and had no signs of any going wrong. I replaced the OPS and the oil pressures are now where they should be.

[Jrs3800]

I would check with a gauge or replace the oil pressure sending unit... If the oil pressure goes up then good.... But if its low then Uh oh...

[ImJJames]

After searching forum and reading other peoples oil pressure issues, I am kinda convinced that what I am seeing is normal. I only drive the car less than 10miles a day.

I have no oil leaks, oil texture looks perfect from dip stick, no white residue under engine oil cap, when engine is cold it starts at 60+ Psi, and I have yet to see a warning "check gauge" ding.

Since I just had my oil change, I will wait for my next oil change(3kmiles) to replace the Oil Pressure Sensor and also to make sure a non-Fram oil filter is used.


Hopefully car will be fine until next oil change.

[yonkerse]

You don't need to wait until the next oil change to replace the Oil Pressure sending Unit. Where its located, only a drop or two of oil will come out when replacing the unit.

The repair consists of this:

1. Purchase a new one from local parts store. (I suggest this so you know what your looking for later)
2. Jack up the right front of the car and remove the tire
3. With tire removed, you should easily see the oil filter. Just behind it (as in toward the center of the car) you should see something like this: (Scroll through the thread to find the picture..)

viewtopic.php?f=19&t=17034

4. Unplug the wire going into it, thread the old sensor out and thread in the new one until snug.
5. Put the tire back on and your done. Start the car and hopefully your oil pressure is higher!