1982 cadillac rear wheel drive 4.1 V6 oil light on

[paul]

my daughters 82 sedan deville with the buick V6 has the oil light on. car has about 75000 well serviced miles. I have to check car today. she said light went on in a 5 mile to work trip . checked oil at work and was full. drove home but light was still on. no notice of any engine noise. could it be the pump? or just a bad pressure switch or wire. I know this engine is no smooth runner or powerhouse. If it is oil pump is it a bugger to change?. thanks

[Derek]

Could be the pump but I'd think that might make some noise.  Is it on all the time or when hot?  I'd check that the switch isn't bad, also check wiring near the switch for worn spots that could be grounding out.  Had an '84 Lincoln that oil light came on at certain speeds, turned out engine vibration/wind was pushing the wire, which had a bare spot, against metal under the hood and grounding it out.  A piece of split-loom solved that problem for good.

[Dave Shepherd]

First issue is whether the op is really low, get a mechanical gage on it at the oil sender port, see what it really is, that said these engines were famous for weak oil pumps, the front engine cover which housed the pump used to wear, hence low pressure.

[Paul]

Thats for the responces. I went over and started the car. The engine fired up and oil light was on.  Engine sounds great no valve noise or anything out of the ordinary. The exhaust is new from the manifold back so you can hear good. I let it run for a few minutes then shut it off and went to my local parts store to get a oil pressure switch. They had to get it out of town so ill have it tomorrow and install that and check the wiring. hopefully that will take care of it. she said she was turing the corner to her work place when the light went on. I dont see any connection but who knows with cars. I talked to a old mechanic buddy of mine who was real familiar with that and the V6 engine. he seemed to think that with only 75000 miles and regular service that the switch was more the problem than the pump considering the age of the car. I  hope so. He said that back in the day people not changing their oil was the main reason for the falure. That particular engine was one that had to have regular sceduled maintence and alot of people were used to the bullet proof V8s of the 60s and 70s that you could go for longer periods of time not changing the oil. Thus the failure of many a V6 back then. I blame the cafe standards and environmentalism run amuck but thats not offering techinical advice so ill stay on the subject. I will let you knowo the outcome as this is her only ride and it must be fixed. its truly a comfortable and wounderfully riding car.

[Rusty Shepherd CLC 6397]

It's a sad commentary on 1982 Cadillacs, but the 4.1 V6 is probably the most reliable of the three engines that were available that year since the 5.7 diesel and the first year HT4100 were the alternatives. You're right, though; that's a handsome, comfortable, and smooth-riding automobile.

[paul]

OK the car has been fixed. Heres what happened. i ordered a new oil sending unit. next day the wonderful parts guy ordered a tempature switch so he had to order the right part and that ate another day. This is a V6 so you can actually change this from ubove if you have a switch removal socket because this is in a tight spot. i have long since misplaced mine so off i go to parts store. I pull switch put some sealant on threads sparingly and install. Start car oil light is still on. So i spend the next hour try to finfd my plian old wire tester. I take tester turn on key and touch the prongs. Nothing. I inspect wire and plug. Looks in good shape. I start to think. is this fused. Could very well be. So i pull panel under steering colomn and try to see fuses. dont have enough light or my glasses. spen another 10 minutes looking for them. On this car are 2 seperate fuse panels . the main one has lots of wire harnese in front of ir making it hard to see if you got good vision. The second panel which is off to the left of it only has 2 fuses. I pull the 15 amp fuse and notice its blown. So i go out back to a junker and pull a fuse. put t and yes juce to the plug. I plug it into the switch and start the car . oil light is out and what was a nail biter was just a minor glitch. But what caused this. This is what i think. My daughters boyfrind is the master sterioo cobber. for some reason he was trying to chnge her power antenna (probably to impress me ) he unbolted the radio and just left it sit there with nothing securing it. so when my daughter turned the corner to pull into work the radio moved and maybe toughed a wire and poped the fuse. OR the swich shorted out and popped the fuse. You be the judge. Anyway here isi how the procedure should go if this happens to anyone else.

Oil light goes on. By all means stop driving the car .  first check the fuse panel its a 15 amp fuse and it sits to the left of the main fuse panel all by itsself. Next check the wiring at the plug and as much of it as you can. Test to see after you replace fuse if plug has juice. If you got juice and fuse is not poping plug it back into oil switch . if fuse blows replace switch. i would recomend replacing switch anyway its a 8 to 10 dollar item and car is over 25 years old. If none of that cures your problem then remove switch and do a oil pressure test. you should have about 18 pounds at a warm idle and 35 to 45 pounds at driving speed. If its low oil pressure then you will need to rebuild the pump. The pump gears are easy to change and you dont have to remove any front cover . just the oil filter and cover. The pump gears slide down and you slide the new gears in . coat them with a generous portion of cam lube or somthing of that nature. i lucked out this time and it was just a simple fuse and switch replacement. i hope this will help out someone in the future if this problem arises.