Oil Recommendations for Caddy Northstar

[ssmokn]

I maintain my father's 2002 Northstar equipped Caddy Deville.

The car has 8K miles on it. Manual calls for 5w30

I change the oil (7qt capacity) at 1K, 3K and 5K with Chevron 10W30. No noticable oil consumption.

The old man wanted to go synthetic so I started using Mobil 1 10W30 at 6K. Now at 8K I noticed he used about 1 quart of oil.

I suspect the Mobil 1 is too thin for the likes of this motor.

I'm thinking at the next change I will try GC 0W30 or Mobil 1 SUV 5w40 (Delvac 1).

Anybody have any experience with oils that work well in this motor?

Thanks.

 

[MikeW]

If the car calls for 5w30 why not use 5w30? If it doesn't call for synth, you can certainly use it, and M1 is fine, just use the 5w30. Even the group IIIs would probably be fine, especially if the car doesn't call for synth specfically.

As far as the oil consumption, I don't know why everyone gets so bent out of shape about this, especially in small quantities (a quart between changes). Going up in viscosity, above what the mfgr recommends, simply to eliminate that small amount of consumption. You probably better off with the consumption using the correct oil, than no consumption using thicker oil.

 

[JohnBrowning]

Yea a thicker 30 wt might just solve it but it is doubtful. Let us know if the 5W40 SUV oil solves this. THe 5W40 is not going to hurt anything at all.

 

[Santo Fontana]

quote:

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Originally posted by MikeW:
If the car calls for 5w30 why not use 5w30? If it doesn't call for synth, you can certainly use it, and M1 is fine, just use the 5w30. Even the group IIIs would probably be fine, especially if the car doesn't call for synth specfically.

As far as the oil consumption, I don't know why everyone gets so bent out of shape about this, especially in small quantities (a quart between changes). Going up in viscosity, above what the mfgr recommends, simply to eliminate that small amount of consumption. You probably better off with the consumption using the correct oil, than no consumption using thicker oil.

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The reasons car makers spec the oils they do in america is still under debate. I would only use a dino 5w30 in very cold weather.

 

[JohnBrowning]

I ran 5W40 Redline in -18F weather all last winter! I could not even tell it was winter by cranking.

 

[ruking77]

I have run Mobil One 5w30 in a Z06 Corvette for 62k with 15k oil and filter change intervals.

Chevrolet OEM recommends Mobil One 5w30. 10w30 will work well also.

Delvac One 5w40, aka Mobil One Truck and Suv is actualy slightly better! I run it in a VW Jetta TDI application and it is a superb group IV, off the shelf, The only issue I have with interchangeability is the higher cost of the 5w40. But the truth is mixing and matching is just fine.

 

[williar]

With 8K miles and a 2K OCI the engine is hardly broken in! Oil consumption during breakin is normal. I'd stick with M1 5w30 & a 7500 mi OCI, or run dino 5w30 with a 3K OCI.

 

[JohnnyG]

If you go to Bruce Nunally's Cadillac website, you will learn more than you ever thought possible about maintaining your Caddy. I've been on that board for about 2 years now, and I can tell you this about motor oil in a Northstar.
1) The engine does NOT like Mobil1, and according to the GM engineer it's not neccesary. The engine was designed to go 300,000 miles on dino. Use the weight specified and change using the oil life indicator.
2) DO NOT use 5W-40 ANYTHING in this engine, this is very bad advice and will stick the rings. Maybe not immediately, but eventually. This will end up making the oil consumption much worse over time. Use an SL oil only, preferably GF-3.
3) DO NOT baby this engine. Run it up to redline once in a while, it's very good for the oil consumption problem if it ever occurs.
4) DO NOT overfill this engine with oil. If you must put the full 7.5 quarts in, make sure it does not go over the FULL mark with the engine hot. Now I don't mean hot like just coming off the dragstrip after 3 consecutive runs, just hot like coming back from a normal 30 minute drive. This engine will run forever with 5 quarts of oil in it. This is just enough oil to wet the very tip of the dipstick WHEN COLD (which is when I check my oil..it's more convenient) The 7.5 quarts was put there for 3 or 4 other reasons which I will not go into at this time.
And YES I use GC in my '99 STS. It didn't like it at first, but suddenly at about 5600 miles on it, the darn thing just took off! Last 300 mile run gave me about 27.5 mpg highway with the GC. I think this oil is a pretty good choice for a Northstar. The biggest reason is that I think someone on this board wrote that GC has very little or NO VII's. None would be outstanding for this motor. Tomorrow will be the first run on a new crancase full of GC. When the engine changed performance characteristics so suddenly and dramatically, It scared me. I thought the oil may have sheared or something, so I changed it. I'll check back in after tomorrow's trip to let you know what happened.
Finally, the achilles heel of this engine is overheating. DO NOT let this motor overheat. Keep the rad fins clean, fill it with THE SPECIFIED coolant, and change it at the proper time. If your engine has Dexcool in it, DO NOT mix any green coolant with it...very bad.
http://caddyinfo.netgetgoing.com/

 

[JohnnyG]

I forgot to mention something. I bought my STS used and the rings had already been stuck from gentle driving/improper oil "application". I have, over the course of 16 months, gotten the oil useage down to acceptable levels. Acceptable for me is 5600 miles on just less than a quart of GC. When I first got the car I was filling the engine to the full mark and getting about 500 miles to a quart of oil! I reduced my oil consumption by following the advice of the GM engineer and the great people on the website I mentioned in my last post. My lowest oil usage early on was with Mobil Conventional Drive Clean in 10W-30 (this 1999 engine calls for 10-30 only). Regular Mobil oil (dino) is what is put in at the factory usually.

 

[ssmokn]

JohnnyG - Thanks for the relevant and useful info.

What make you think 5W40 would make the rings stick? Delvac 1 is very shear stable. Heck the GC 0W30 is almost a 40 weight.

Off to the website you mentioned for some reading.

 

[JohnnyO]

My folks have Caddys too, which I maintain. The people on the Caddy boards are mostly very knowledgable. Me however, I run M1 10w-30 (recommended weight) in mom's '99 since if part of the problem is the rings coking up, well then in my mind full syn M1 ought not do that. I learned about doing some full throttle blasts in 2nd gear from 55 mph to 80 mph and abruptly letting off several times ("Officer, I was just getting the gunk out." "C'mon down to the station, we'll get the gunk out of YOU."--Bill Cosby). This has greatly lessed the oil use. Generally the Caddy boards will tell you to run BITOG's favorite dino oils or a blend with an AC filter though a few run K&N's. I have Valvo Synpower in mom's right now with a K&N, at the time it was a bunch cheaper than M1 and the N* takes a crapload of oil. Dad's new '04 calls for 5w-30 which I just drained and put M1 in the other day. Run it hard once in a while and just put in 7 qts, not the full 7.5 and this should keep the consumption down. The newer ones are not supposed to consume as much oil, probably the best compromise between cost and performance would be a blend like Valvoline's DuraBlend or Castrol's. If your dad's '02 calls for 5w-30 then use 5w-30, I would only use 10w-30 in summer.

Click here for my Cadillac UOA

 

[JohnBrowning]

Anyone telling you that 5W40 will stick your rings does not know much about engines. Their is no way that Delvac-1 or M1 SUV 5W40 is going to stick you rings!!! As a matter of fact you are more likely to stick your rings with a 5W30 non CI-4 oil. Ring sticking on GM engines is do to the poor piston and ring design. The only things none to help are CI-4 oils, combustion cleaning, Auto-Rx and piston soaks with LC. THe problem is so common that they have had multiple bullins on the subject matter and a redesigned ring set (napier rings).

Anyone claiming that the NorthStar is a 300,000 mile engine is just not being very honest. Most engine remanufactureing companys will not touch the N.Star line of enignes because they are designed to be dispossable!

A CI-4 oil combined with Lube Control and yearly combustion cleaning are you best deffense against the all to common ring filling and corbon issues they engines have.

It is odd that most Cadilac owners get their vechiles servived at the Dealer or other lube place and still this problem is so common. You would tink that with the plentiful supply of cheap dino 5W30 tht more N.Star engines would be lasting 300,000 miles as a matter of common occurance! Trust me most leak oil badly by 80,000 miles and are chugging oil like commerical diesel by then as well. Most never make it to 200,000 by a long shot before they are needing to be replaced because of excessive oil consuption and poor performance!

 

[ssmokn]

I agree that Delvac 1 isn't going to contribute to stuck rings. If anything it should help keep the rings clean. I'm going with the 5W40 at the next change and I'll take my chances.

My Dad loves his Deville but the car does nothing for me. When he gets tired of it I'll buy it off him (I usually do). He went from a Towncar to the Deville. In my opinion the Towncar runs rings around the Deville (and I'm a GM guy at heart). Front wheel drive luxury cars just don't cut it for me.

 

[JohnnyG]

JohnBrowning, You are very biased against the Northstar engine, that has been made very apparent in our past discussions. The things that I am telling you here have been said by a GM engineer, they could never be from my own experience as you well know. The reason GM says that 0W-40 anything is bad for the Northstar is specifically due to the large amount of VII improvers needed in conventional dino oil to get that wide of a viscosity range. 10W-30 was called for in pre 2000 engines due to its narrow viscosity range, and the fact that it has flat tappets. More recently, with new roller cam followers/engine/ring designs, 5W-30 has been permitted. I don't know a thing about the CI-4 spec, but I do know that VII's when burned in a combustion chamber, leaves a lot of deposits behind. Some of these stay in the combustion chamber where they can accumulate and become known as carbon, some of them are forced down into the ring pack where they can stick rings. Further, I think that SUV oil/4X4 oil/High Mileage oil etc. is the biggest farce put on the consumers since Castrol started calling Group II oils synthetics. The reason I have chosen to use GC 0W-30 is because I learned on this board many months ago that this oil should not contain ANY VII's. Many other oils may meet the same requirement, including Amsoil, which is a fine product. The Northstar engine as well as several other GM engines are designed with a very agressive honing pattern on the cylinder walls. This is by design, and is intended to keep the rings well lubed, hence the long therotical engine life...the rings and cylinders will just not wear out. Now, start putting the wrong oil in that engine, or too much oil, etc. and strange things start to happen. The rings get stuck, oil consumption goes up, and a vicsious cycle begins. If you want to give advice on Toyota engines, be my guest, but when it comes to the Northstar you need to start checking some facts. There are many Northstars out there with more than 80,000 miles on them and many more with over 150,000 to 500,000 miles. Please don't let your personal biases in favor of imports influence the advice given on this board. I do not have anything personal to gain from any of this information and would just like to keep owners of Northstar engines on the right track with their maintenance and oil selection.

 

[JohnnyG]

By the way, I just got back from my 300 mile trip and I said I'd post an update on the GC. The Northstar engine is loving it. 60,000 miles on it now and it's running like new, got 26.7 MPG coming back @ 75 - 80 mph. No oil usage whatsoever. Did manage to work it out to redline on an interstate merge, just to keep things cleaned out. The recent change in performance must have been due to the "summertime" gas or from some other reason. It was not due to the GC changing or doing anything wierd. The lower RVP requirements for summer forces the oil companies to remove a lot of the 'anes from the gas, butanes, propanes, etc. This may result in a fuel with more BTU/gallon than in the winter. Or it could just be that my car doesn't like the cold.

 

[JohnBrowning]

JohnnyG, I am extreemly biased against engines placed in a $50,000 dollar car that burns oil excessively, leaks oil early on due to poor seal designs and have carbon and ring sticking issues. I am also biased against the Gen III engines includeing the LS1 and LS6 for the same reasons plus piston slap issues. I am not impressed with a Luxury car engine that has a hard time liveing day to day after it's 3 year 36,000 miles warranty is up!

It should be a given that any car you buy from an econo box to a Sports car should not do the following for at least the first 120,000-200,000 miles: Piston Slap, Excessive oil consumption, Carboning, Ring Sticking, Seals leaking. One should also be able to easily rebuild the engine at any machine shop. All parts should be available from common sources. Heads ands and blocks should be easily serviced and none dispoasable (not useing oversized valve stems). The rings the engine ships with ought to be the right ones to begine with!

The NorthStar is a smooth engine and makes ample power for it's size but it is anything but durable!!!!! The most inovative piece of technology on the N.Star is the PCM. The algorytms(sp) that allow it to limb home with out coolant are truly genius.
Even if I was leaseing one I would still make these same remarks because they are true! I think to often people have selective hearing and only hear the positive things and neglect to hear the neative. This is especialy true if it is something they own. Just because I own something does not dimish the truth of it's short comeings.

Rest assured that Cadilac will have to do a major redesign of the N.Star soon to keep up with it's competition. The big advantage that Cadilac has is that most people do not buy Cadilacs most Lease them. A leasee could car less about long term durability! The people that do buy Cadilacs either trade in and up every 2 years or they drive them very little!

I was laughing so hard at the N.Star being a 300,000 mile engine on Dino 5W30 I almost feel out of chair!!!

Please do not take this personely either! I just think that the information you are getting from your Cadilac site is very skewed and biased in it's own rite. I do not think I have ever wittnessed a N.Star Cadilac with it's origanal engine running properly with anything close to 300,000 miles ever! I am sure their are a few out their but they are anything but common place!

 

[JohnnyG]

I thought this board was about oil. Why do you not address any of the oil issues?

 

[JohnnyO]

quote:

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Originally posted by JohnBrowning:
JohnnyG, I am extreemly biased against engines placed in a $50,000 dollar car that burns oil excessively, leaks oil early on due to poor seal designs and have carbon and ring sticking issues.

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"You need to work it hard and blow it out some to work the rings, it's a high-performance engine."--heard many times on the Caddy boards.

Thing is most Caddy drivers are old folks like my parents, who mostly putt to Wal-Mart at a speed barely above idle. Nice running engine, don't get me wrong, but you'd think Cadillac would know who their customers are and design engines accordingly. Just go back to slow-turning 500 cube torque monsters mated to a 2.29 axle. A company out in CA builds 2200 lb 4 seat sand cars with 800 hp blown Northstars in back. Now THAT sounds like fun.

Somebody else is marinizing N*s and putting them in boats, I could like that too. I've gone to running full syn in my folk's cars, hopefully to keep the rings from sticking. Mom's burns a ton of oil, dad's is too new to tell. Also I figure the M1 won't foul the plugs as it gets burned, I know the plugs on my (2 stroke) jetski last a lot longer with synthetic. Changed mom's oil 682 miles ago, I check it yesterday and it's down 1/2 qt.

I used to work at an Olds-Caddy dealer, I can tell you that the pre-N* HT4100 engine didn't burn oil but it leaked big time too. All I'm saying is put the engine in the Corvette where it belongs instead of going to waste hauling old folks at 58 mph in the left lane with the blinker on.

quote:

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I was laughing so hard at the N.Star being a 300,000 mile engine on Dino 5W30 I almost feel out of chair!!!

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Me too.

[ May 10, 2004, 10:25 AM: Message edited by: JohnnyO ]