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Oil Pressure Light --- After Oil Change & 7.5 Quarts Added


newbold1

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Just bought a 1996 DeVille for my daughter. It has about 176K miles on it. The oil pressure light keeps coming on at low RPM's... generally at idle when the RPM's are about 650 - 600. If I sit for any length of time I will get a message stating to turn off the engine. However, if I give just a little gas to bring up the RPM's to about 800 or so the light goes out.

I had the oil changed right after I bought the car. Currently it has 7.5 quarts of Valvoline Max Life 10w30 oil.

Questions:

1. I hear that using 10w40 may fix the problem. I will try that on the next oil change. Anyone able to tell me why that helps?

2. What kind of repair work does the car likely need in order to fix this problem altogether? Any ideas on the cost that will be involved if the likely problem turns out to be the problem? Is this a problem that would typically require major repair work?

3. There are no DTCs being set by this problem. Is that unusual? My DTCs are completely clear.

4. Last question... I am freaking out when that light comes on and especially when the message says to shut off the engine. I am worried to death that I am going to do serious damage to the engine and the fact that it has 176K miles on it makes me that much more nervous about it. Should I be as worried as I am about this problem?

Thanks in advance for any insights you may be able to offer!

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Seems like a few of us had this, and there were several solutions. I just removed the plug from the oil sensor in the front of the car near the oil filter, and sprayed wd40, and compressed air, on both the sensor electrical connectors, and plug to remove oil & dirt that accumulitated there. Then I reconnected, and never saw the message again. I did this about a year or so ago. I'll let others comment on changing the oil grade. I have always used synthetic oil (10 w 30) in this car since new.

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You need to determine if it is a faulty oil pressure sender. One way to do that is to install a new OEM sender and see if the situation clears up.

The absolute best way is to plumb in a mechanical pressure guage temporarily.

Oil pressure specs from 1998 Seville Service Manual pg. 6-14 and 2004 Deville manual pg. 6-15;

Minimum pressure at normal operating temperature at idle = 5 PSI

Minimum pressure at normal operating temperature at 2,000 RPM = 35 PSI

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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Just bought a 1996 DeVille for my daughter. It has about 176K miles on it. The oil pressure light keeps coming on at low RPM's... generally at idle when the RPM's are about 650 - 600. If I sit for any length of time I will get a message stating to turn off the engine. However, if I give just a little gas to bring up the RPM's to about 800 or so the light goes out.

I had the oil changed right after I bought the car. Currently it has 7.5 quarts of Valvoline Max Life 10w30 oil.

Questions: SEE MY RESPONSE IN BOLD, MIKE

1. I hear that using 10w40 may fix the problem. I will try that on the next oil change. Anyone able to tell me why that helps? The thicker viscosity causes an increase in pressure. If this car has been sitting for awhile without running, the case half seals could have shrunk. The reason I use 15W40 Rotelle is because its a Diesel oil and it has MORE friction reducing zinc in it. As you may or may not know, environmentalists were successful in having zinc levels reduced in oils. Our 96 has rubbing lifter/cam elements that are succeptible to increased wear as a result. You might also try a high mileage oil, they have more seal conditioners. Is MAX LIFE considered a high mileage oil?

2. What kind of repair work does the car likely need in order to fix this problem altogether? Any ideas on the cost that will be involved if the likely problem turns out to be the problem? Is this a problem that would typically require major repair work? My theory is that the case half seals leak dropping the pressure at idle, it could also be, a bad oil pressure switch, it could be due to a bad oil pump or bearing clearances. One more thing that it could be is that the CRANK PULLEY is NOT torqued to spec, allowing the OIL PUMP drive to slip.

3. There are no DTCs being set by this problem. Is that unusual? My DTCs are completely clear. No DTC will be set

4. Last question... I am freaking out when that light comes on and especially when the message says to shut off the engine. I am worried to death that I am going to do serious damage to the engine and the fact that it has 176K miles on it makes me that much more nervous about it. Should I be as worried as I am about this problem? Well I think there is cause to worry, but what is happening is that AT IDLE, your oil pressure is dropping below the oil pressure switch ON threshold (I believe its 5 PSI). I have in the past, used two feet (one on gas one on brake at a stop) to step up the idle to make the light go away, but I must say, since I started using 15W40 NO light. It might get better over time, if the car was sitting without being run as the seals swell up from the conditioner in the oils. Take it for a long ride, you might recondition the seals, if it has been sitting.

Thanks in advance for any insights you may be able to offer!

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Just bought a 1996 DeVille for my daughter. It has about 176K miles on it. The oil pressure light keeps coming on at low RPM's... generally at idle when the RPM's are about 650 - 600. If I sit for any length of time I will get a message stating to turn off the engine. However, if I give just a little gas to bring up the RPM's to about 800 or so the light goes out.

I had the oil changed right after I bought the car. Currently it has 7.5 quarts of Valvoline Max Life 10w30 oil.

Questions: SEE MY RESPONSE IN BOLD, MIKE

1. I hear that using 10w40 may fix the problem. I will try that on the next oil change. Anyone able to tell me why that helps? The thicker viscosity causes an increase in pressure. If this car has been sitting for awhile without running, the case half seals could have shrunk. The reason I use 15W40 Rotelle is because its a Diesel oil and it has MORE friction reducing zinc in it. As you may or may not know, environmentalists were successful in having zinc levels reduced in oils. Our 96 has rubbing lifter/cam elements that are succeptible to increased wear as a result. You might also try a high mileage oil, they have more seal conditioners. Is MAX LIFE considered a high mileage oil?

2. What kind of repair work does the car likely need in order to fix this problem altogether? Any ideas on the cost that will be involved if the likely problem turns out to be the problem? Is this a problem that would typically require major repair work? My theory is that the case half seals leak dropping the pressure at idle, it could also be, a bad oil pressure switch, it could be due to a bad oil pump or bearing clearances. One more thing that it could be is that the CRANK PULLEY is NOT torqued to spec, allowing the OIL PUMP drive to slip.

3. There are no DTCs being set by this problem. Is that unusual? My DTCs are completely clear. No DTC will be set

4. Last question... I am freaking out when that light comes on and especially when the message says to shut off the engine. I am worried to death that I am going to do serious damage to the engine and the fact that it has 176K miles on it makes me that much more nervous about it. Should I be as worried as I am about this problem? Well I think there is cause to worry, but what is happening is that AT IDLE, your oil pressure is dropping below the oil pressure switch ON threshold (I believe its 5 PSI). I have in the past, used two feet (one on gas one on brake at a stop) to step up the idle to make the light go away, but I must say, since I started using 15W40 NO light. It might get better over time, if the car was sitting without being run as the seals swell up from the conditioner in the oils. Take it for a long ride, you might recondition the seals, if it has been sitting.

Thanks in advance for any insights you may be able to offer!

Mike,

It seemed to me that the simplest first step toward a solution would be to try the 15w40 Rotelle oil. I just had an oil change so I figured that the oil filter didn't need to be replaced right now. So... just a simple drain and refill using 15w40 is all I did this evening. Having done that I took the car for a drive through some subdivisions where I would be doing a lot of stopping / idling. Well, the light never came on at all. I let the car idle in my driveway for about 15 more minutes after the drive and still no warning light. It was after sundown and only about 65 degrees outside though. I'm going to drive the car to work tomorrow (30 miles) in stop / go traffic. Hopefully, I won't get the warning light.

I sure hope that this is all that it took to resolve the situation. If so... what a relief.

I don't mind spending the money to fix the car as needed but hope I can get a chance to recover from the initial outlay of cash spent on buying the car first before I start having to do repair work.

Thanks,

David

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That is good news I surmise that your car has been sitting, and once you start to drive it, you will perk up the case half seals. Good Luck tomorrow, Ill keep my fingers crossed, Mike

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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The last oil change slip was still in the car when I bought it and it showed a mid-January date on it. I think it was traded-in shortly thereafter. So, the car has probably been sitting on the lot for about 2-3 months. I doubt it was driven around because it was all the way in the back of the sales lot off to the side in vacant property that wasn't even paved. That area had a bunch of junker cars and this almost perfect looking DeVille. I guess they figured it had little value due to the 176K mileage and so they just parked it and didn't even put it on the main lot for sale.

I think the car received a lot of TLC from the previous owner. It was very clean and CarFax showed that it was owned by the same person all the way back from when it was first purchased.

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  • 2 weeks later...

I thought about starting a new thread but this is the same issue so I will post here. A while back my wife had an experience with the "stop engine" and bells about low oil pressure in our 97 Deville. When I got there the car was fine and I drove it home. Then last week I drove about 200 miles then stopped and let the car sit for about 1-1/2 hours and the oil light came on and would not go off. I tried a fast idle and it would go off then as idle came back down it would come on. Then I checked codes and it finally went away. I still had 200 miles to drive home. I set the cruise on 75 and the light flickered off and on but never stayed on. Then in the last 50 miles no light at all. I managed to jack the car up yesterday and manipulated the wiring around the oil adapter and was going to clean the connectors but I found 2 connectors close together. They were very hard to get to. I managed to get one plug off but then I realized that I could barely reach it, so I spent the next 20 minutes trying to get it back on. I was doing this by touch because I could not get myself under the car far enough to see what was there. I then took it for a drive, about 3 miles, and the warning and chime were going off all the way. I then checked and cleared the codes and no problem since in about 20 miles.

Can someone scan a copy of the oil adapter picture for a 97 Deville, so I will know what plug to clean. I am going to take it to a local garage and use their lift so I will have better access to and see what I am doing. If that does not work I am going to add 10w40 oil on the next change. How hard is it to change the sensor and what tools did you use to change it? There does not look like much room to work.

To update the work on my 97 Deville, I just changed the waterpump, the tensioner and idler pulleys.

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Its a tough location to get it, I will second that. Here is a photo of the oil filter adapter, keep in mind that the plug has to be turned so that the connector lines up. On my 96 there is a metal piece that you can remove with 4 bolts that will give you more room. It is much easier to remove the two bolts holding the adapter, than to try to change the switch with it in place. Replace the two seals, and use something to hold them firmly in place when you put the adapter back in place. Use long extensions and universals and a 10 mm socket. Mike

OilPressureSwitch005.jpg

This photo shows the oil pressure switch and how you must turn the plug to have it fit

OilPressureSwitch002.jpg

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Thanks Mike, I think the plug I had off was the oil pressure switch. It felt like there were 2 plugs next to one another though. I may try to jack the car up and crawl under again to see if I can get a better look at whats there. I am not a big fan of working under a car with just a 2 ton floor jack in place. I can't get to my ramps, but I do not like them either. I had one collapse on me one time, thank God, I saw it going and got out of the way just in time.

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The Crank Sensors are right there also. Try taking off the inspection cover if you have not done so, the bolts face forward and it covers the space between ahead of the carriage.

I will be more careful now with my jacks, but I am pretty careful as it is, I always have a safety jack stand in place, chocks on the wheels etc. But mechanical failure like that is scary...

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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The last oil change slip was still in the car when I bought it and it showed a mid-January date on it. I think it was traded-in shortly thereafter. So, the car has probably been sitting on the lot for about 2-3 months. I doubt it was driven around because it was all the way in the back of the sales lot off to the side in vacant property that wasn't even paved. That area had a bunch of junker cars and this almost perfect looking DeVille. I guess they figured it had little value due to the 176K mileage and so they just parked it and didn't even put it on the main lot for sale.

I think the car received a lot of TLC from the previous owner. It was very clean and CarFax showed that it was owned by the same person all the way back from when it was first purchased.

How is the oil pressure holding up? A member has questioned my hypothesis regarding the case half seals via PM.

Look at the bottom of your engine, is your pan wet? Do you appear to be leaking oil?

Did you replace your oil pressure switch? I think I said that when I let my car sit for a month without oil and without running I had a persistant oil light until I went with 15W40, I changed the oil pressure switch and it made no difference. I had 95,000 miles at the time and I leak oil badly. The problem is this, if its NOT the oil pressure switch, the correct oil is being used, are we saying its a bad oil pump? I had 95,000 miles when it began to show itself, no main bearing or rod bearing noise. I know that large clearances at the bearings can lower pressure also.

What made me begin to think about the case half seals causing low RPM oil pressure problems was a member who came here and said, he took it to the dealer after replacing the oil pressure switch and the mechanic said it was case half seals leaking, and I scoffed at the suggestion. That is UNTIL, I looked closely at the case halfs in the following photo. I traced a small segment in red, where seals seal the oil galley between the case halfs, if these seals leak at this location INTERNALLY, oil pressure could be lowered in my opinion. If the case half seals can cause an external leak, why couldn't they cause an internal leak? When you look at the case halfs you notice that and OIL GALLEY is created between the halfs, see this photo

engine_20004-1.jpg

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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  • 2 months later...
The last oil change slip was still in the car when I bought it and it showed a mid-January date on it. I think it was traded-in shortly thereafter. So, the car has probably been sitting on the lot for about 2-3 months. I doubt it was driven around because it was all the way in the back of the sales lot off to the side in vacant property that wasn't even paved. That area had a bunch of junker cars and this almost perfect looking DeVille. I guess they figured it had little value due to the 176K mileage and so they just parked it and didn't even put it on the main lot for sale.

I think the car received a lot of TLC from the previous owner. It was very clean and CarFax showed that it was owned by the same person all the way back from when it was first purchased.

How is the oil pressure holding up? A member has questioned my hypothesis regarding the case half seals via PM.

Look at the bottom of your engine, is your pan wet? Do you appear to be leaking oil?

Did you replace your oil pressure switch? I think I said that when I let my car sit for a month without oil and without running I had a persistant oil light until I went with 15W40, I changed the oil pressure switch and it made no difference. I had 95,000 miles at the time and I leak oil badly. The problem is this, if its NOT the oil pressure switch, the correct oil is being used, are we saying its a bad oil pump? I had 95,000 miles when it began to show itself, no main bearing or rod bearing noise. I know that large clearances at the bearings can lower pressure also.

What made me begin to think about the case half seals causing low RPM oil pressure problems was a member who came here and said, he took it to the dealer after replacing the oil pressure switch and the mechanic said it was case half seals leaking, and I scoffed at the suggestion. That is UNTIL, I looked closely at the case halfs in the following photo. I traced a small segment in red, where seals seal the oil galley between the case halfs, if these seals leak at this location INTERNALLY, oil pressure could be lowered in my opinion. If the case half seals can cause an external leak, why couldn't they cause an internal leak? When you look at the case halfs you notice that and OIL GALLEY is created between the halfs, see this photo

engine_20004-1.jpg

Sorry about not replying for a long time. I started a new job recently and haven't been on the board in a while.

We haven't been driving the car a whole lot yet and so it does tend to sit in the driveway for 2-3 days at a time. I hope that when we start driving it more often that maybe that will help the situation.

Swapping out all of the oil for 15w40 has helped greatly. The oil light now only comes on when the oil level is truly low. Bad news is that the oil level becomes low pretty quickly. The pan is definately wet and there are oil stains all over the driveway where we've been parking the car. My 1996 SLS had a very slow leak so I never did anything about it. I might get 1-2 drops in the garage each night. With this car it looks like we're losing a lot more oil than that each day. Maybe when we drive it more often the seals will recondition as you had described and the leak will be less severe.

I sure hope so. I understand that a repair job to correct this problem is pretty labor intensive... expensive.

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While this could be a case half leak, that is very expensive to repair, this could be something simple. Try the following

Retorque the pan bolts to spec

Check the cooler lines and fittings

Check the oil filter adapter for leaks

Check your CAM covers for leaking

I am glad your Low Oil Pressure light is staying out that's great and that the 15W40 is helping

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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While this could be a case half leak, that is very expensive to repair, this could be something simple. Try the following

Re torque the pan bolts to spec

Check the cooler lines and fittings

Check the oil filter adapter for leaks

Check your CAM covers for leaking

I am glad your Low Oil Pressure light is staying out that's great and that the 15W40 is helping

BBF, I really respect, how you look, for the simplest solutions first ...

before marching on, and making your head hurt ...

catmando ...

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It's more optimism than anything else, I tend not to think the worst first. Why note eliminate the simple things first right? My style can be methodical and tedious however, and I appear off track at times for this reason. But its just the way I tend to approach things. Thx

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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  • 1 year later...

This turned out to be a severe case half leak. The repair was in the mid $2K range at the dealership. We had the work done and that was almost a year ago now. The car doesn't consume oil at all now. Never have to add any between oil changes. The repair was close to blue book value of the whole car but in the end it was worth doing because my daughter has a nice looking comfortable and safe car with no car payments and low insurance costs. Gas mileage would be an issue but she barely drives 40-50 miles a week and the car still gets over 20 mpg on average. We only have to fill it up about once a month at the most.

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This turned out to be a severe case half leak. The repair was in the mid $2K range at the dealership. We had the work done and that was almost a year ago now. The car doesn't consume oil at all now. Never have to add any between oil changes. The repair was close to blue book value of the whole car but in the end it was worth doing because my daughter has a nice looking comfortable and safe car with no car payments and low insurance costs. Gas mileage would be an issue but she barely drives 40-50 miles a week and the car still gets over 20 mpg on average. We only have to fill it up about once a month at the most.

Thank you, this confirms my thinking that the case half seal can cause low oil pressure at idle

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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