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First oil change advise...


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Good afternoon,

I'll be taking my car in for her first oil change on Tuesday Im aware I should use 10W 30 however I am wondering if the 96 Northstar Engine was designed for Natural, Synthetic or Synthetic Blend?

I would take it to the dealer but I will only be back home for a day and dont have time to wait for the dealership.

91,670 miles 1996 Concours

I jut dont wanna screw it up or mix an improper oil in her. any recommendations would be appreciate. :)

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The FSM (and the Owner's manual) says to use 10W-30 certified for use in motor vehicles in your Northstar.

My Cadillac dealer recommended Mobil 1 as a premium oil for my 1997 Eldorado Touring Coupe Northstar. Many here and elsewhere will argue against synthetic oil. The differences between synthetic and conventional ("dino") motor oils are primarily

  • Synthetic oils are more expensive.
  • Synthetic oils do not contain the waxes (heavier hydrocarbons) that cause conventional oils to become thick or congeal at very low temperatures. Synthetic flow better at lower temperatures than conventional oils of the same grade because of this.
  • Synthetic oils do not contain the napthas (lighter hydrocarbons) that give conventional oils their flash points (the temperature at which they will catch fire and burn if there is a spark), so synthetic oils have much higher flash points.
  • Synthetic oils do not have other impurities found in conventional oils that absorb water and are part of the process of sludge formation.

Another point that will stir controversy here and elsewhere is the use of 5W-30 oil. The FSM says to use it if the car is not to be started cold at igh ambient temperatures (over 80 F or 90 F I believe) but this applies to dino oils. The FSM recommends 5W-30 or 10W-30 for temperatures below 30 F. The 1997 FSM never mentions synthetic oil at all.

Synthetic oils are not a different "stuff" from conventional oils. Conventional oils are based on mineral oil, which is refined from crude petroleum as a product with a specific range of molecular weight, with heavier ("waxes") and lighter ("napthas") hydrocarbons at specified low percentages. Synthetic motor oils are manufactured through a different process that essentially eliminates waxes and napthas more thoroughly but it is still mineral oil. The very important are of additives is mostly the same for synthetic and dino oils.

There is an important additive for motor oils called ZDDP. This is a zinc compound that provides film strength for oils that is important in metal-to-metal surfaces like cam-lifter interfaces, cam chains and sprockets, cam chain tensioners, piston rings, and all libricated surfaces in a cold engine. ZDDP is hard on catalytic converters so its use has been reduced in modern oils over that when your car was made. Newer oils have about half the ZDDP as oils made in the 1990's. BUT your oil life monitor (OLM), the part of your car's computer that determines when you should change your oil and provides a CHANGE ENGINE OIL message when it's estimated oil life is 20% or less (10%?), has a 2:1 safety factor built into its algorithms. So, you can safely use modern oil and use your OLM as a prompt to change your oil.

SUMMARY: I recommend 5W-30 Mobil 1 if your car is in tip-top shape and you want to keep it that way, or if you don't drive many miles and long oil change intervals or sludge are an issue. But 10W-30 dino oil is perfectly fine if you prefer that.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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I would use 10W-30 Rotella diesel oil in your car - it does not have roller cam followers and the Rotella oil has extra antiwear additives that regular 10W-30 does not. If you can't find 10W-30 Rotella oil, use the 15W-40 Rotella. The engine was designed to use conventional oil so there is nothing to be gained by running synthetic oil in that car.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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Just because a oil is for diesel's does not mean it’s inherently better for a gas engine. Diesel oil is engineered with a higher amount of dispersant and detergent package to deal with the increased amount of soot and other hydrocarbon combustion by-products present in a diesel engine that is not in a gas engine. I would not use diesel oils in these engines.

There is no benefit to running diesel oil any more. Since all diesel trucks have gone to a particulate filter and low ash motor oil, most of the additives that were put into the Delos, Rotellas, etc. are gone.

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Yes thats the problem I have no clue of whats been used in the car However based on the impecible condition of the car and All te GM replacement parts i found receipts for I can only assume the previous owner took the car to the dealer for servicing and oil changes and they would have used WHATEVER the designed the engine to be used with.
I also was taught (many moons ago) that if you been using "Dino" Oil, Keep using "Dino" Oil if you were using Synthetic ONLY USE SYNTHETIC never try to convert so hence my question and THANKS
Ill just do a regular oil change Tuesday night. I generally get oil changes every 6-8 weeks regardless of the milage I drive just because I tend to be overly meticulous

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Your car has an oil life monitor. Hit info, and when you get your oil changed with conventional 10-30, hold the reset button till it says XXX OIL LIFE LEFT. save your money. When the car displays a message that you have 10% oil life left, change. 6-10 weeks is extremely excessive, and a waste of oil and money. Never get anything flushed either. Drain and refill your fluids when you save $$

To do so.

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Just because a oil is for diesel's does not mean it’s inherently better for a gas engine. Diesel oil is engineered with a higher amount of dispersant and detergent package to deal with the increased amount of soot and other hydrocarbon combustion by-products present in a diesel engine that is not in a gas engine. I would not use diesel oils in these engines.

There is no benefit to running diesel oil any more. Since all diesel trucks have gone to a particulate filter and low ash motor oil, most of the additives that were put into the Delos, Rotellas, etc. are gone.

The diesel oils have more ZDP than the conventional oils which is needed for the flat tappet engines link the pre-2000 Northstars. Other than using the diesel oil, adding some GM EOS (5 ozs per oil change) would restore the oil to the level of ZDP that was in the oils when the engine was produced.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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I knew this question would start an oil thread. The FSM says specifically NOT TO USE OILS ENDING WITH -40 or anything other than -30, as in 10W-30. Page 0B-3 of the 1997 FSM:

ENGINE OIL VISCOSITY

The recommended oil viscosity for this vehicle with the temperature is above 0 F (18 C) is SAE 10W-30.

Engine oil viscosity (thickness) has an effect on fuel economy and cold-weather operation (starting and oil flow). Lower viscosity engine oils can provide better fuel economy and cold weather performance. However, higher temperature weather conditions require higher viscosity engine oils for satisfactory lubrication. When the temperature will be very cold and never above 60 F (16 C), SAE 5W-30 should be used in all models [the manual covers Eldorado, Seville, and Deville with the Northstar, both VIN "Y" and VIN "9"]. SAE 20W-40 or oils of other viscosity rating or quality designations are NOT recommended at anytime.

NOTICE: Using oils of any viscosity other than those viscosity's (sic) recommended could result in engine damage.

When choosing an oil, consider the range of temperatures the vehicle will be operated in before the next oil change. Then, select the recommended oil viscosity.

Since it's the middle of summer, use 10W-30. Good quality dino oil (Shell, Exxon, Pennzoil, Quaker State, etc.). Look for either the starburst or the newer "doughnut" symbol that certifies that the oil is certified by the SAE for use as a motor oil:

donut-starburst.jpg

Since the Northstar went to roller tappets in 2000, there are those who believe that flat tappets are failure prone, particularly since ZDDP content of motor oils has been reduced to avoid damage to catalytic converters in oil-burners. There is no evidence that ZDDP goes below acceptable levels using any good quality motor oil in Northstars while the oil level monitor is not showing the CHANGE ENGINE OIL message on the DIC every time you turn on the key. If there is any doubt, there is always Blackstone Laboratories.

If you are insecure about that and don't want to take the trouble to send samples of your oil to Blackstone Laboratories for the first time you drive through an oil change interval, you can use GM EOS (engine oil supplement) as recommended by KHE. It's intended for use when breaking in new engine components such as camshaft/lifters, piston rings, cam chains and sprockets, rocker arm fulcrums, roller bearing center pins, and other metal-to-metal surfaces.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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SORRY, Wasnt trying to start an oil thread the one thing that the car did not come with was the owners manual and im ticked at that but hey the car runs and good. My Oil Life says 77% but the little windsheild reminder sticker say 94,000mi or April 30, 2013...LOL (no thats not a typo) and it looks dirty to me or worn. I figured it was better to ask here than try and "google" it and get all types of wrong answers from individuals whom have never owned or worked on a Northstar.

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If the oil looks good on the dip stick and has no strange smell, just keep track of the OLM and start thinking about an oil change when it gets below 50%. Be sure and get to it when it starts getting to 20% or below, and if you forget and see the CHANGE ENGINE OIL message, get it done ASAP because the OLM is at 10%.

I think a good time to change the oil in an engine if you like to baby it is when the OLM is at about 40%. Others will point out that you are wasting money if you don't wait for the CHANGE ENGINE OIL message. It's your car, your call.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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SORRY, Wasn't trying to start an oil thread the one thing that the car did not come with was the owners manual and im ticked at that but hey the car runs and good. My Oil Life says 77% but the little windshield reminder sticker say 94,000mi or April 30, 2013...LOL (no thats not a typo) and it looks dirty to me or worn. I figured it was better to ask here than try and "google" it and get all types of wrong answers from individuals whom have never owned or worked on a Northstar.

Assuming the oil hasn't been changed since April of 2013... it needs changing ASAP or even sooner...LOL

But, since the OLM is "SUPPOSED" to go to -0- at a one year time interval, I think it has probably been changed and the present windshield sticker was not replaced with a new one.

With all THAT being said... if it looks dirty... "I" would change it.

Oil is a lot cheaper than an engine.

I do not and would not use a Fram filter... I only use AC Delco, but I always thought this commercial made a good point... it is from the early to mid 70's.

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I really enjoy threads like these. My late father was a big fan of Chevron oils and hydraulic fluids for his cars, trucks and tractors and WIX filters. Does anyone have any opinions one way or the other about either in the Northstar engine?

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I really enjoy threads like these. My late father was a big fan of Chevron oils and hydraulic fluids for his cars, trucks and tractors and WIX filters. Does anyone have any opinions one way or the other about either in the Northstar engine?

I used to use RPM Delo (Diesel Engine Lubricating Oil) which is made by Chevron in my big trucks and Chevron hydraulic fluid in the lift cylinders when I had dump trucks.

Used it for several years and about 750,000 miles while I had my trucks.

Never had any problems with it at all.

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Just because a oil is for diesel's does not mean it’s inherently better for a gas engine. Diesel oil is engineered with a higher amount of dispersant and detergent package to deal with the increased amount of soot and other hydrocarbon combustion by-products present in a diesel engine that is not in a gas engine. I would not use diesel oils in these engines.

There is no benefit to running diesel oil any more. Since all diesel trucks have gone to a particulate filter and low ash motor oil, most of the additives that were put into the Delos, Rotellas, etc. are gone.

The diesel oils have more ZDP than the conventional oils which is needed for the flat tappet engines link the pre-2000 Northstars. Other than using the diesel oil, adding some GM EOS (5 ozs per oil change) would restore the oil to the level of ZDP that was in the oils when the engine was produced.

I know many refuse to accept expert opinion on the ZDP subject but nonetheless here is a reply from a GM expert.

Over the years there has been an overabundance of engine oil myths. Here are some facts you may want to pass along to customers to help debunk the fiction behind these myths.

The Starburst Oil Myth -- The latest myth promoted by the antique and collector car press says that new Starburst/ API SM engine oils (called Starburst for the shape of the symbol on the container) are bad for older engines because the amount of anti-wear additive in them has been reduced. The anti-wear additive being discussed is zinc dithiophosphate (ZDP).

Before debunking this myth, we need to look at the history of ZDP usage. For over 60 years, ZDP has been used as an additive in engine oils to provide wear protection and oxidation stability.

ZDP was first added to engine oil to control copper/lead bearing corrosion. Oils with a phosphorus level in the 0.03% range passed a corrosion test introduced in 1942.

In the mid-1950s, when the use of high-lift camshafts increased the potential for scuffing and wear, the phosphorus level contributed by ZDP was increased to the 0.08% range.

In addition, the industry developed a battery of oil tests (called sequences), two of which were valve-train scuffing and wear tests.

A higher level of ZDP was good for flat-tappet valve-train scuffing and wear, but it turned out that more was not better. Although break-in scuffing was reduced by using more phosphorus, longer-term wear increased when phosphorus rose above 0.14%. And, at about 0.20% phosphorus, the ZDP started attacking the grain boundaries in the iron, resulting in camshaft spalling.

By the 1970s, increased antioxidancy was needed to protect the oil in high-load engines, which otherwise could thicken to a point where the engine could no longer pump it. Because ZDP was an inexpensive and effective antioxidant, it was used to place the phosphorus level in the 0.10% range.

However, phosphorus is a poison for exhaust catalysts. So, ZDP levels have been reduced over the last 10-15 years. It's now down to a maximum of 0.08% for Starburst oils. This was supported by the introduction of modern ashless antioxidants that contain no phosphorus.

Enough history. Let's get back to the myth that Starburst oils are no good for older engines. The argument put forth is that while these oils work perfectly well in modern, gasoline engines equipped with roller camshafts, they will cause catastrophic wear in older engines equipped with flat-tappet camshafts.

The facts say otherwise.

Backward compatibility was of great importance when the Starburst oil standards were developed by a group of experts from the OEMs, oil companies, and oil additive companies. In addition, multiple oil and additive companies ran no-harm tests on older engines with the new oils; and no problems were uncovered.

The new Starburst specification contains two valve-train wear tests. All Starburst oil formulations must pass these two tests.

- Sequence IVA tests for camshaft scuffing and wear using a single overhead camshaft engine with slider finger (not roller) followers.

- Sequence IIIG evaluates cam and lifter wear using a V6 engine with a flat-tappet system, similar to those used in the 1980s.

Those who hold onto the myth are ignoring the fact that the new Starburst oils contain about the same percentage of ZDP as the oils that solved the camshaft scuffing and wear issues back in the 1950s. (True, they do contain less ZDP than the oils that solved the oil thickening issues in the 1960s, but that's because they now contain high levels of ashless antioxidants not commercially available in the 1960s.)

Despite the pains taken in developing special flat-tappet camshaft wear tests that these new oils must pass and the fact that the ZDP level of these new oils is comparable to the level found necessary to protect flat-tappet camshafts in the past, there will still be those who want to believe the myth that new oils will wear out older engines.

Like other myths before it, history teaches us that it will probably take 60 or 70 years for this one to die also.

- Thanks to Bob Olree – GM Powertrain Fuels and Lubricants Group

Edited by Z15
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Wow - the guru (also from GM Powertrain) who used to frequent this board was the one who used to promote using the diesel oil in the flat tappet engines.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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Assuming the oil hasn't been changed since April of 2013... it needs changing ASAP or even sooner...LOL

But, since the OLM is "SUPPOSED" to go to -0- at a one year time interval, I think it has probably been changed and the present windshield sticker was not replaced with a new one.

Jim, I agree with the first part of this comment. A lot of people forget about the one year limit on oil. Of course that statement doesn't include my Volt, which states 2 years.

Unfortunately, I have never witnessed an OLM going to "0" after one year. Yes, I realize that it's also supposed to track time as well as the many other factors that impact oil life, but I've taken all of my cars past one year and have not seen it drop.

As for my two cents worth on oil recommendations, you can't tell if an oil is bad by looking at it. If it "looks dirty" you will only be changing it for aesthetic reasons.

All motor oils are generally made to be backward compatible. The fact that ZZDP levels were reduced means very little since those additives were replaced with boron or othe A/W compounds that do just as good a job.

I'd use a modern synthetic of the proper grade (10W-30) in this car and never look back.

The most important thing about an oil change on this year car has been overlooked in our replies, and that is to NOT overfill the crankcase. This car will hold 7.5 quarts with an oil filter replacement, but will run perfectly fine forever on 5 quarts. Do not fill the level to the FULL mark on the dipstick, but keep it about 1/4" down.

Never underestimate the amount of a persons greed.

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excellent point. I run 7 in mine all the time. never had a problem. I find it does not leak as much on my deville either when I do this

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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The most important thing about an oil change on this year car has been overlooked in our replies, and that is to NOT overfill the crankcase. This car will hold 7.5 quarts with an oil filter replacement, but will run perfectly fine forever on 5 quarts. Do not fill the level to the FULL mark on the dipstick, but keep it about 1/4" down.

Im sorry if this is a stupid question in two parts but what happens when you over fill crankcase and why keep it a 1/4 low?

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If you overfill the crankcase (by filling it to the full mark with the engine is cold instrad of hot), the excess oil is churned up by the crankshaft and the PCV system burns up the vapors.

When you have the oil changed, have them refill with 7-1/2 quarts of 10W-30 oil - that is the factory recommended fill volume.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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You can choke up an engine pretty good with oil froth if you overfill it. That's true of any engine with a PCV vale, which means anything made since the early 1960's.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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