1995 Buick LaSabre oil light


trenton309
11-09-2004, 06:27 PM
I was driving my Dad's car home today when I passed another car. After passing at around 70mph the oil light came on. I was close to home and continue on. When I got home I checked the oil. It was full. The engine sounded like it was pinging a little. I started it up again with no light on. This was my Dad's car. Did I push it to hard? The car was 141,000 miles and he changes the oil every 3000 miles. Any suggestions?

buickmastermind
11-09-2004, 06:34 PM
The oil pressure switch may have a problem, or the oil might be due up for another change. It is also possible that the oil might be the wrong wheight, but I doubt it if the oil actually gets changed every 3000 miles (usually people who do that wouldn't get the wrong wheight of oil, seeing as how you have to know stuff about cars in the first place to know to change the oil every 3,000 miles) . If the dip stick has a scored area on it, the oil should be filled right to the top of that area. I don't think that it is an issue unless the light comes on again, and starts to regularily.

avatar307
11-10-2004, 01:53 PM
Provided the oil pump is working correctly, an oil level anywhere within the cross hatched area on the dipstick should be sufficent to keep the oil pressure light from coming on.

The oil pan might be bent and blocking the full availabilty to the oil pickup to the oil pump. The oil pump could be dying, but I seriously doubt it (I've got 175,000 on my 1995 with 2 large accidents and my oil pump is fine.)

The oil pressure sensor could be faulty, the connections may be corroded, or one of the wires may be loose. All of which would create more electrical resistance which the computer could interpret as low oil pressure (depending on the exact electrical function of the sensor).

If you stepped down on the gas really hard, you could of simply sloshed the oil in the engine backwards and caused the engine to loose it's oil pressure reading. Depends on how many Gs you were pulling, LOL.

However, it is not unheard of for an engine to read a loss of oil pressure when accelerating sharply. For two reasons, one the movement of the liquid within the engine. Two, the engine was running at a lower RPM initially, which means the oil pump was spinning at a slower speed. Upon increasing RPMs, there is a couple seconds before the increased speed to the oil pump results in the full increased oil flow to the top of the engine. (Simply due to the viscosity of oil and the path traveled.)

If it starts happening regurally or happens during light driving, then I would get concerned. If you just want to tinker with the engine, go buy a manual and read up on the oil pressure sensor. It will give you the reading to check with e multimeter, and you can get you hands good and dirty finding and checking the sensor connector. LOL

buickmastermind
11-10-2004, 09:23 PM
"However, it is not unheard of for an engine to read a loss of oil pressure when accelerating sharply. For two reasons, one the movement of the liquid within the engine. Two, the engine was running at a lower RPM initially, which means the oil pump was spinning at a slower speed. Upon increasing RPMs, there is a couple seconds before the increased speed to the oil pump results in the full increased oil flow to the top of the engine. (Simply due to the viscosity of oil and the path traveled.)"

This does happen, but it shouldn't because the oil pump on the 3800 is a ge-rotor oil pump. It is a significantly more efficient type of oil pump. Also, the feed for the pump is in the center of the oil pan toward the back, in a posistion where that shouldn't be an issue. As avatar siad, it still might be an issue. Don't worry until it becomes a regular problem.

strefo
12-10-2004, 08:33 AM
I am having a similar problem with my 95 LeSabre. The oil light is coming on regularly at low idle. Oil level is just fine and was just changed 2 weeks ago. We have 114,000 miles on the car. Hubby mentioned there is a small ding in the oil pan when he changed the oil but, as far as I know, it's been there as long as we've had the car. Any ideas???

buickmastermind
12-10-2004, 11:17 AM
The worst it could be is that the oil pump is dying. One thing you could try is using a heavier wheight oil, such as a 10w40 instead of 10w30. Use 4 quarts of the lighter one, and one of the heavier one. If the light persists, use only 3 of the lighter one, and two of the heavier one. Keep doing this until you are using only the heavy whieght oil, and hopefully it should stop. If that works, however, it points to the oil pump going bad. The last thing that it could be is the pressure switch is reading lower than it should.

strefo
12-10-2004, 11:46 AM
Thanks!!! He did put 10W30 in for the winter time (on my Father's advice from forever ago), we normally run 10W40 in the summer.

We suspected the oil pump but, that is not exactly a known problem on this car. We know 3 other people that have the same car with 150,000 miles up to 200,000+ and no problems there. Of course, there is always one, huh? =-)

buickmastermind
12-10-2004, 02:08 PM
If that's the case, I would use the 10w40 year round. Also, not sure what brand(s) of oil you use, but it would be a good idea to substitute a quart of Rislone in next time you change the oil. It will clean all the oil paths in the motor from grime and carbon layers.

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