: Nothstar fairytails



dutch STS
06-18-06, 06:22 AM
I'm new here, so maybe there is allready a thread about this,

but I a long time ago I heard a story about the design and performance of the Northstar engines.

Somebody told me Northstar engines were build to last several miles without oil in them and some other things like that. (note, the person that told me these things is a real big Cadillac fan, so he thinks there is no better engine than the Northstar, and I share that thought), but are there things like this know by you?

Was the Northstar engine designed to last under the wurst conditions?

JohnnyO
06-18-06, 07:57 AM
Not without oil, but there is a "limp home" mode that the engine will run on 4 cylinders at a time if there is no coolant, like if you had a bad leak or blown hose or whatever.

dutch STS
06-18-06, 08:07 AM
ok, tnx. Does are the things I am trying to find out.

But it also switches of cilinders when driving at one speed, doesn't?

eldorado1
06-18-06, 09:49 AM
No, it doesn't turn off cylinders. You're confusing the northstar with some of the latest engines with "displacement on demand"

Ranger
06-18-06, 04:16 PM
Depends on what you are talking about here. When in the limp home mode (overheated engine), the Northstar will alternately shut down left & right bank injectors and just pump air through the cylinders to aid in cooling and thus allowing the 50 miles with no coolant. It is not displacement on demand where it will disable valves and run on 6 or 4 cylinders as needed.

The Northstar was designed and tested to be a high performane engine. It was tested at WOT for hours on end and it needs to be run hard. Occassional WOT burst are recommended and if you have never driven one at WOT, you are in for a treat.

No engine will run without lubrication.

dutch STS
06-18-06, 04:26 PM
ok, so the story that it will run 90 miles without oil isn't true, but it will run for a longer period at the max rpm (don't exactly know what WOT is).

Haha, btw; I was telling a friend of mine your story JohnnieO about the coolant . He has a '92 STS and a '90 Allante both without Northstar. He's trying to sell me his STS, but I want a Northstar model. He says his engine is just as good.

After him and me spoke on the phone, he went for a short drive and the temp. ran up really high causing the engine coolant to boil. He stopped and saw a cut hose. He drove home carefully refilling water all the time.

haha, I could't stop laughing, because I just told him the story about the Northstar engine and how it reacts to a cooland leak. And he said that had now extra value. It was like the Cadillac Gods heard him say that.

Ranger
06-18-06, 05:10 PM
WOT = Wide Open Throttle

eldorado1
06-18-06, 07:07 PM
He stopped and saw a cut hose. He drove home carefully refilling water all the time.

haha, I could't stop laughing, because I just told him the story about the Northstar engine and how it reacts to a cooland leak. And he said that had now extra value. It was like the Cadillac Gods heard him say that.

:histeric:

JohnnyO
06-19-06, 08:07 AM
It was like the Cadillac Gods heard him say that.

That can happen.
Also, Cadillac came out with (I think) the first variable displacement motor in (I think) 1980, known as the V-8-6-4. It would run on either 8, 6, or 4 cylinders depending on the demand for power and to save on gas. Basically it ran like crap and jerked a lot and within a few years most people clipped the wire so it just ran on 8 cylinders all the time. I worked at a Cadillac dealer in 1983-84 and we did this. 1981 was the last year they made that engine.

codewize
06-19-06, 10:22 AM
He probably has the 4.9 which isn't even close to a Northstar. I think the 4.5 in my STS is a closer resemblance. I often wonder if it was a test bed for the Northstar development.

Also the claim to fame on the 'no coolant' thing was 50 miles at 50 miles per hour.

No oil would cause immediate failure in any engine. However due to the high oil volume and small displacement of the Northstar, the oil change duration is extended beyond other engines. 12,000 miles or 1 year.


ok, so the story that it will run 90 miles without oil isn't true, but it will run for a longer period at the max rpm (don't exactly know what WOT is).

Haha, btw; I was telling a friend of mine your story JohnnieO about the coolant . He has a '92 STS and a '90 Allante both without Northstar. He's trying to sell me his STS, but I want a Northstar model. He says his engine is just as good.

After him and me spoke on the phone, he went for a short drive and the temp. ran up really high causing the engine coolant to boil. He stopped and saw a cut hose. He drove home carefully refilling water all the time.

haha, I could't stop laughing, because I just told him the story about the Northstar engine and how it reacts to a cooland leak. And he said that had now extra value. It was like the Cadillac Gods heard him say that.

dutch STS
06-19-06, 11:19 AM
Ok, thanks. This is the information I was looking for. It's nice to know things like these about a brand/model you like. Espaccially if everybody says your crazy driving in a car like these. Gasoline prices have never been as high as they are now (about $1,75 per littre) and I pay at least double the amount of road-tax as people with European or Japanese cars, because it goes by the weight of your car here.
So you have to come with good arguments to drive a car like this, other than "I'm crazy 'bout Cadillac". Haha.

Ranger
06-19-06, 04:39 PM
He probably has the 4.9 which isn't even close to a Northstar. I think the 4.5 in my STS is a closer resemblance. I often wonder if it was a test bed for the Northstar development.

Also the claim to fame on the 'no coolant' thing was 50 miles at 50 miles per hour.

No oil would cause immediate failure in any engine. However due to the high oil volume and small displacement of the Northstar, the oil change duration is extended beyond other engines. 12,000 miles or 1 year.
That has nothing to do with the extended oil change interval.

codewize
06-20-06, 09:29 PM
Ohhh ? I didn't look this up but from a logistical standpoint it certainly makes sense to me. So then why is there such a long change interval.

That has nothing to do with the extended oil change interval.

Ranger
06-20-06, 09:46 PM
If you are refering the the increase from the 7,500 mile cap pre 2000 to the 12,500 cap after 2000, it was due to the addition of the roller finger followers in 2000. On the pre 2000 engines, under ideal conditions the OLM did not cap at 7,500 because the oil was dirty, but because it was worn out (for lack of a better term). The flat tappet lifters had a shearing effect on the oil which wore it out sooner. The Guru could explain it better than I but that is it in a nut shell.

STS 310
06-20-06, 10:51 PM
Me and other members would rather not test the limits of the Northstar. It might be able to with stand those extremes, but why test if not necessary? Nice to know if I am in Death Valley and my wife is pregnanat and having a baby within the next hour, but really. When my STS over heated I shut it down and towed that girl. Why becasue I could for one, and another, I just could.

Shes a beast and a hearty one to boot, but test her to the limit, and she will tax your ass something serious if it s is critical.

Actually Ive tested the Northstar to great extremes with NO coolant for short durations. I wont do it again.

No castrophic problems, but I wont ever go there again....

GreenMachine
06-21-06, 08:47 PM
^good to have it even if you never need it.

JohnnyO
06-22-06, 08:57 AM
Ohhh ? I didn't look this up but from a logistical standpoint it certainly makes sense to me. So then why is there such a long change interval.

1. Modern EFI engines don't get as much fuel dilution in the oil as older carburated ones.
2. Modern oils are way better than oils from 15 or 20 years ago.
3. A N* holds 7.5 quarts, which on average is 50% more than most other engines. Since there's more oil, it doesn't wear out as fast.

codewize
06-22-06, 10:29 AM
I think this is what I said ? Hi quantity of oil in small engine means longer oil life. No?


3. A N* holds 7.5 quarts, which on average is 50% more than most other engines. Since there's more oil, it doesn't wear out as fast.

chevyorange
06-30-06, 09:20 PM
Can speak from experience, limp mode works great. I have a disability and while I wasn't happy to find out I had a HG problem, I'm glad I wasn't stuck on the freeway for any amount of time.

Mccalist
06-30-06, 09:46 PM
My engine got real hot once whent the water pump belt broke. Why didn't the "limp home mode" prevent this? (I only drove about 5 miles.)

Ranger
06-30-06, 09:56 PM
The car doesn't go into limp home mode until it reaches 265 degrees I believe. The limp home mode is not designed to prevent an overheat, but to enable the engine to continue to run with out a melt down.