Oil light flicker at idle, Then

[BodybyFisher]

In another thread I mentioned that I was getting a flickering oil light at idle. I put my foot on the brake and raised the idle and it would go off at 950 RPM.

The other day, after about a 15 mile ride, I came to a stop, the oil light came on quickly, and this message appeared, STOP ENGINE - LOW OIL PRESSURE. To really get your attention the CHIME that I miss from my 91 goes off; BONG BONG BONG BONG! that last action really drives your blood pressure through the sunroof.

It has gotten worse, lighting up at 40 coasting to a stop..it only seemed to happen when the engine was hot. I thought, ok... NO tappet sound, (like lifter noise) from low pressure. I thought, I am using 10W40 (stay calm I know 10W30 is the spec, but I am more concerned with the decrease in the zinc anti-wear compounds than I am with anything else, the zinc was not decreased in 10W40). Plus my engine has NEVER sounded better, it was sounding like a SINGER sewing machine. Today I took it to the car wash and the car jockeys face turned white after he parked my car in the drying area and he ran into the office after seeing the STOP ENGINE message and bong. I tried to stop him to tell him it was OK, but he took off Never said a thing to me however

Today I pulled my oil filter adapter off and replaced my Oil Pressure Switch. I went to my local Cadillac Genuine GM Parts Department to find them closed, FN closed! I called another dealer and its parts department was closed, WTF? A retail business CLOSED on a Saturday. Spoiled SOBs. So I logged on to ACDelco.com, and searched for a local distributor. They did not have an AC Delco part only Standard. (What a bad name for a product, Standard), Standard, and I believe they make a good part and bought it, I think they used to make Blue Streak when I was a kid, it was a premium ignition part.

R&Ring the oil filter adapter is not hard, use a 3/8" 12" long extension, universal swivel and 10mm socket. Snapping the plug back in was quite difficult however, its just lucky that I have the hands of a surgeon! The next time I do this job I am going to plug it in before I bolt in the oil filter adapter if there is enough slack in the wire. There are 2, +two inch long 10 mm bolts holding the adapter and there are two o-rings also. I replaced my o-rings last year so I didn't worry about replacing them today. I just coated them with NYLOG sealant and when I started the engine I didn't notice any leaks. I am going to buy a few sets of o-rings to keep on the shelf as I would rather have replaced them.

If you look at the following photos you will notice that the old switch was wet in the contacts, since there is a rubber seal, I can only figure that it was leaking near the pins. This was definately a source of an oil leak. I sprayed the plug and plug contacts with electrical contact cleaner to get the oil out. Screwed on a new PF61 AC filter and I was done.

Here is a photo of the oil filter adapter, the o-rings, and the switch. Notice the switch is wet with oil inside.

This is a photo with the new oil pressure switch installed and the o-rings held in place with NYLOG

During the job, I found out that my water pump is leaking. Interestingly enough it looks like its been leaking for a long time, but not fast. I had to add a gallon of coolant last week for the first time, but I knew my radiator side tank was bad and leaking so I chalked it up to the side tank. It has not been overheating at all, but there has been a coolant smell for about a month or two. So next week I order the radiator, water pump, upper hose (has rub marks on it from a bracket), oil pressure level switch, ISS sensor and dog bones. Oh here is a good one, the ACDelco distributor can get me an ACDelco radiator for $280 (Brasington wants $260 with shipping) but they have an aftermarket radiator for $145, he tells me that its identical and that the AC delco is over priced, an AC DELCO distributor, imagine that? If in fact there is no difference, GM better wake up. I did this once before with my 91 and it WASN'T identical and took it back and bought an AC.

Going to take a long ride now to get it hot and see if the light stays off..

Miss being here everyday, miss you guys! Hope this helps someone, Mike

[Bruce Nunnally]

Hope that fixes it; nice detail & photos.

Not necessarily the case here, but sometimes vendors recommend the item they have the largest markup on. Sometimes GM seems to price things for profit though, as in the case of original mufflers for example; the GM parts cost as much or more than an aftermarket system when one might expect by virtue of superior quantity if nothing else the GM part would be much less expensive.

[Ed Hall]

I also installed an aftermarket radiator on my 93 Northstar powered Allante and it looked identical to the original equipment radiator that I replaced.

[BodybyFisher]

Thanks, I think I will do that, for $145. I think I will shop around however and see what brands I can buy and research them a bit. I wonder if its possible to buy one with more cooling capacity.

[Texas Jim]

I have been known to just have a local radiator MAKE one with more rows of coolant tubes. Gives a lot more capacity and much better cooling. Used to do that on high performance cars that I played with. Also on pickup's that I pulled heavy loads with.

[BodybyFisher]

I have been known to just have a local radiator MAKE one with more rows of coolant tubes. Gives a lot more capacity and much better cooling. Used to do that on high performance cars that I played with. Also on pickup's that I pulled heavy loads with.

Yes, I have heard about doing that. I think if I was keeping the car, I would think about improving the radiator capacity, I wonder if the Oil Life Monitor would adapt to cooler coolant and thereby cooler oil?

[Cadillac Jim]

If the problem doesn't turn out to be the switch, the oil pump is the next thing to look at. Mine was starting to flicker at idle when I would pull off the freeway to a stoplight, or in heavy traffic on a hot day -- with 5W-30 oil. If I had been able to do the timesert job, I would have changed the oil pump while I was looking at the front of the engine.

[BodybyFisher]

If the problem doesn't turn out to be the switch, the oil pump is the next thing to look at. Mine was starting to flicker at idle when I would pull off the freeway to a stoplight, or in heavy traffic on a hot day -- with 5W-30 oil. If I had been able to do the timesert job, I would have changed the oil pump while I was looking at the front of the engine.

Oh that's a comforting thought...that's exactly what mine was doing, it would be a shame if yours was the pressure switch also. Had you changed it?

At idle the oil pressure drops to 5 psi I think, the threshold for the switch is low also, I think when the oil is hot, the slight drop in pressure at idle is enough to trigger the switch, when the switch is leaking. I had quite a bit of oil everywhere. I had noticed a lot more oil on the ground also, so the case half leak concerned me also, we have had discussions here about the case half seal damage causing a low pressure condition, I think its related to the oil valley seals, see photo below.

I need to go for a ride this morning we will see, I am using 10W40 so if it flickers with 10W40 I am REALLY in trouble.. I think with the wet switch leaking by the pins however I found my problem, will advise.

[JimD]

Yes, I have heard about doing that. I think if I was keeping the car, I would think about improving the radiator capacity, I wonder if the Oil Life Monitor would adapt to cooler coolant and thereby cooler oil?

Adding a larger than OEM capacity radiator will not alter the temperature of the coolant circulating in the engine cooling passages. You will have the ability to reduce the temperature of the coolant in the radiator, but the thermostat determines how much of that "cooler" coolant flows through the engine.

Reserve capacity is OK, but cooler is not necessarily better (in the engine). A warmer engine will vaporize the condensation out of the oil faster than a cooler engine. A warmer engine is more efficient that a cooler engine.

The engine oil cooler was dropped at some point in the Seville ('98?) and it became part of a towing package option.

[BodybyFisher]

Good points Jim, very true. I do have the oil cooler and plan to retain it when I replace the radiator.

Was Mobil 1 (synthetic) spec'd for the cars without the oil cooler do you know?

[JimD]

Dino 10W-30 for '98 and '99; dino 5W-30 for 2000-2004.

I don't remember what oil was spec'd. when the Northstar was installed in rear wheel drive cars.

[nigel]

i had a similar problem 6 years ago with my '97 eldo. the oil light and stop engine message would come on at idle with a hot engine.

i fitted a new switch and still had the problem. i had the pressure checked with a shop gauge and found that at idle there was only 3psi but at 2000 rpm the motor had a good 40psi.

i decided to fit an aftermarket gauge to keep an eye on things.

the front motor mount meant i had to remove the switch and extend the supply from the filter housing using parts from a plumbing shop.

after modifying and installing the relocated switch the oil light never came on again and the dash gauge and shop gauge indicated 10psi at idle

i have a picture but the board says i have reached my global limit??

[BodybyFisher]

i had a similar problem 6 years ago with my '97 eldo. the oil light and stop engine message would come on at idle with a hot engine.

i fitted a new switch and still had the problem. i had the pressure checked with a shop gauge and found that at idle there was only 3psi but at 2000 rpm the motor had a good 40psi.

i decided to fit an aftermarket gauge to keep an eye on things.

the front motor mount meant i had to remove the switch and extend the supply from the filter housing using parts from a plumbing shop.

after modifying and installing the relocated switch the oil light never came on again and the dash gauge and shop gauge indicated 10psi at idle

i have a picture but the board says i have reached my global limit??

Thanks, I think you are limited to 64K for photos, Mike

[BodybyFisher]

I washed and waxed my car and took it out for about a 25 mile WOT beating. First I want to say that I do believe that 93 octane makes a difference, it is more powerful and snappy. Changing to 93 is more obvious because I have been using 87 because of tight finances, but 87 made it feel piggy and heavy.

The used of 10W40 has quieted my engine down no more lifter noise or rattling as i hit 5600 RPM, she wants to run now. I am NOT condoning/recommending the use of 10W40, but I have been happy with the results at 94,000 miles, where the tolerances have loosened a bit I am sure. Anyone who thinks that I am getting poor gas mileage due to the heavier oil should be advised that last night on the highway I reset my Avg. MPG monitor and I was getting 27-28 and rising on level open roads at 65 - 70.

I am happy to report that my OIL LIGHT problem has been fixed.... and I didnt have an oil burning smell when I got back from flogging it..... yeah!

One problem down a bunch more to go...

[kens96]

Glad to hear that it was the fix !

[Cadillac Jim]

I was looking at oil leaks during running (no oil on the garage floor), a flickering oil light at idle occasionally with 5W-30 synthetic, struggling with an oil burning problem (about a quart every 1200 miles, and worse after 2500 miles on an oil change -- and managed with two pints of CD2 oil detergent additive right after each oil change), and then I had the head gasket problem. Although all of these is doable in a week, full time, I didn't have a week to work on the car full time or a place to work on it, so that's when I got the remanufactured engine. I don't wait for anyone to tell me anything to do for this engine. The dealer doesn't know about it yet because they haven't seen the car since it went in last July. I'm coming up on 10,000 miles now.

[95SevilleSLS]

I was looking at oil leaks during running (no oil on the garage floor), a flickering oil light at idle occasionally with 5W-30 synthetic, struggling with an oil burning problem (about a quart every 1200 miles, and worse after 2500 miles on an oil change -- and managed with two pints of CD2 oil detergent additive right after each oil change), and then I had the head gasket problem. Although all of these is doable in a week, full time, I didn't have a week to work on the car full time or a place to work on it, so that's when I got the remanufactured engine. I don't wait for anyone to tell me anything to do for this engine. The dealer doesn't know about it yet because they haven't seen the car since it went in last July. I'm coming up on 10,000 miles now.

How many miles are on your car total?

[Cadillac Jim]

I have about 125,000 total miles. See my journal under Supporter's Cadillacs (or click the link).

[Spurlee]

I had the same "flickering at idle when hot" problem with my 1996 El Dorado at about 125,000 miles. I switched to 10W40 and it cleared up immediately.

[winterset]

1) I spray everything down with WD-40. It quiets things down, and keeps parts from rusting / sticking / drying out.

2) my oil light flickered at low idle too. I disconnected the elertrical connector, sprayed compressed air & some kind of cleaner solvent on the electrical connectors & I haven't seen this for about a year now. no tools required (to the best of my memory)

[PAUL T]

Mike,

Glad you fixed the problem. I noticed there was no oil bypass valve in your adapter, did you do away with it or was it just not shown? Mine kept falling out when I would change the oil so I finally did not put it back in. That has been almost 80,000 miles ago.

Paul T.

[BodybyFisher]

Mike,

Glad you fixed the problem. I noticed there was no oil bypass valve in your adapter, did you do away with it or was it just not shown? Mine kept falling out when I would change the oil so I finally did not put it back in. That has been almost 80,000 miles ago.

Paul T.

No Paul there was no oil by-pass. Does that by-pass get used when there is no oil-cooler? I have an oil cooler in my radiator, which I am changing this weekend...

[clarkz71]

Snapping the plug back in was quite difficult however, its just lucky that I have the hands of a surgeon! The next time I do this job I am going to plug it in before I bolt in the oil filter adapter if there is enough slack in the wire.

, I know what you mean Mike, I was lucky and noticed the problem in advance and installed the connector before bolting on the housing.

[BodybyFisher]

Snapping the plug back in was quite difficult however, its just lucky that I have the hands of a surgeon! The next time I do this job I am going to plug it in before I bolt in the oil filter adapter if there is enough slack in the wire.

, I know what you mean Mike, I was lucky and noticed the problem in advance and installed the connector before bolting on the housing.

Clarkz, complicating the problem of course was that when I screwed the new pressure switch in, I lost the position of where the switch snapped it, and it was our 180 degrees. They don't give much room in there..

[iq2hi15]

My '96 SLS did the same thing at every red light. After about 2 weeks the check engine light came on. The code was for a misfire. After replacing the ignition coil and plug on cylinder 5 the oil pressure light never came on again and the car has idled perfectly since.