: Northstar old problems fixed?



sixbangr
10-30-10, 11:56 AM
I am looking to buy a STS. In the past the Northstar v8 had some issues. Are these newer ones better, or should I get a 6? I would prefer the 8 for the power difference.

Subsailor613
10-30-10, 12:49 PM
What "ARE " the old issues as you know them, and we can respond !
If it's the oil usage, they solved that problem... :cool2:

sixbangr
10-30-10, 01:00 PM
Oil and the head gaskets, and I seem to recall a water pump.
See you were on the Flasher, I was on a sub tender. Later with the Trieste ll when the Scorpion went down.

RippyPartsDept
10-30-10, 01:31 PM
probably thinking about the headgasket/headbolt problems

supposedly fixed in 2000 then supposedly fixed again in 2004

we haven't seen any N*s w/ the problem that are 2004 and newer... so i think they did finally fix it

EChas3
10-30-10, 02:22 PM
I have 63,000 miles on my 5-yerar-old 2006 1SG. The 24,000 miles I've put on it have been a joy. I usually drive pretty mild but I've also enjoyed WOT over a hundred times in not yet 2 years.

It burns less than a quart of Mobile 1 in 10,000 miles, about when the OLM tells me to change it. I keep it to spec, so quarterly I add a bit. I'd call that a healthy N*. My wife's 2007 experiences about the same. Her old 1998 STS N* used about a quart every 2,500 miles. I learned elsewhere in Cadillac forums that in that era N*, there was an intentional cross-hatching that was actually a design choice by GM engineers. They have changed the modern N*. (The new V6 has had more reports of excessive oil consumption than the V8's.)

About a month ago, I did smell some coolent after returning from a spirited weekend drive. I had it checked-out and the water pump showed signs of a leak. (In the week before taking it in, I did not smell more coolent but it was down a cup.) They fixed it under warranty but 'should' it fail at 60,000 miles? No. Is it hard on a water pump to regularly run to redline? Probably. Is it still a design weakness? IMHO, Yes. Based on member's reports, the power steering pump has a design weakness, too.

I only recall one post of a HG issue on this forum. A lot of us enjoy the full power band of the 2005-2010 N* STS. Again. this is just my opinion, but if the head gasket issue had not been resolved, we would hear about it!

I wouldn't be afraid to buy an STS but I would set a reasonable expectation. You can buy a these cars cheap for what they are. All premium cars are expensive to fix. When buying, consider the real cost of setting aside $ or an extended warranty. I think the STS cost of ownership is still a great value.

Eldo1953
10-31-10, 07:13 PM
The headgasket problem has been resolved as they went to a different deck design on the top of the block where the head meets the block.

Jesda
11-01-10, 07:40 AM
http://autospeed.com/cms/title_Anatomy-of-an-Engine-the-New-Northstar-V8/A_1569/article.html

Subsailor613
11-01-10, 08:48 PM
Thanks Jesda for that link to "Anatomy of a Northstar V8 engine"
Fantastic insite as to all the inside stuff of the engine, and why's !
I knew that If I was building it myself, I would have chosen certain
things, just as Cadillac did, visibly, from the outside, and the owner's
manual, BUT, now I know that the inside stuff, is also a continuation,
of things I would have done,to further give me, MAX HP, fuel economy,
and reliability. I did most of these on an engine, many years ago.
and am delighted, that most ALL of these choices are in the engine,
I drive, and own, NOW ! The only thing they don't talk about is the
exhaust headers, and they are NOT part of the engine, but they talk
about the intake manifold ?,AND it's design characteristics.
I would be curious as to what we have on a 2005 STS Northstar !
Thanks Again. :cool2::cool2:

turnne
11-03-10, 10:41 AM
http://autospeed.com/cms/title_Anatomy-of-an-Engine-the-New-Northstar-V8/A_1569/article.html

I scanned the article and I find it interesting that it doesn't mention what they did differently from the older generations..ie...to get rid of the oil consumption( been there done that) and the HG issue( never had that issue thank God)



Warren

RippyPartsDept
11-03-10, 04:22 PM
there was some mention of oil consumption

FEM (finite element modelling) was used to model the piston motion and generate a skirt profile for minimal NVH over the whole operating range. Extensive testing was also performed to optimize the ring geometry, tension and end gaps to minimize blow-by and oil consumption

miked
11-04-10, 01:59 AM
FWIW, we have had three vehicles with the "newer" Northstar V8: a 2005 SRX, a 2008 SRX, and a 2008 STS. The engine was/is flawless on all of them. Still love the Northstar.

EChas3
11-04-10, 09:59 PM
I'm convinced the time to buy a particular powerplant is just before it is 'retired'. Every new design has problems. Most just become 'issues' in later models. Once an engine deisgn becomes 'obsolete' I think it is actually perfected. It's 'issues' are known and preventable.

I like to call it Maturity. Kids hate that term. I know I did. Fair enough.

The Northstar is mature... (325 HP, too!)

turnne
11-05-10, 06:49 AM
I'm convinced the time to buy a particular powerplant is just before it is 'retired'. Every new design has problems. Most just become 'issues' in later models. Once an engine deisgn becomes 'obsolete' I think it is actually perfected. It's 'issues' are known and preventable.

I like to call it Maturity. Kids hate that term. I know I did. Fair enough.

The Northstar is mature... (325 HP, too!)

I would tend to agree with you. However it took them about 10 years to get the Northstar bugs worked out.
The issue with an engine that is that old is two fold...there are smoother V8's out there from the competition and the HP ( if one cares ) is on the low end of the spectrum by today's standards
In my mind they needed a new V8 by about 2005...though I understand development costs and their financial situation likely prevented this being viable.
If they were to design new V8, from the ground up today, there is no reason why an expectation of 370-400HP...as well better mileage, emissions and NVH standards could not be expected
Would it likely be less reliable..sure. Everyone in the older Caddy forum here says the V8 engine that preceded the Northstar was much more reliable and much less costly to repair

The 3.8 seemed to have bugs worked out much quicker...though it had intake issues..but not anywhere close to the issues of the Northstars


Warren

RippyPartsDept
11-05-10, 01:06 PM
Warren, you are familiar with the Ultra V8 engine? http://en.wikipedia.org/wiki/GM_Ultra_Engine

i believe almost all the R&D costs were already paid for...

EChas3
11-05-10, 09:53 PM
GM built a lot more 3800's than Northstars. What's more, the cars with 3800's got a lot more miles a lot more quickly.

I think GM placed a little too much faith in the engineers that designed the Northstar. Don't forget that people who will invest their lives in cars get entranced by the technology. They can't help thinking, "This should work just great. The flaw must be in the ...."

I think my original point is valid. Obsolete = Figured-out. Any designer worth the name then must start over!

RippyPartsDept
11-05-10, 10:20 PM
i don't think the N* is obsolete... it's just been discontinued
i do agree that with EChas3 about maturity and that the N* has been figured out though
to me, obsolete means there's something to replace it - similar but better
we don't have that in regards to the N*
the Ultra was going to be that, but oh well...

EChas3
11-05-10, 11:14 PM
OK, obsolete may be a strong term. But I can't tell you how many times I've found hardware & software reach 'end-of-life' and the replacements turn out to be just another example of 'negative progress'.

turnne
11-06-10, 07:39 AM
OK, obsolete may be a strong term. But I can't tell you how many times I've found hardware & software reach 'end-of-life' and the replacements turn out to be just another example of 'negative progress'.

It also means lack of technology as well...and behind from a competitive standpoint
As I said before look how more reliable the engine was( and cheaper to fix) that preceded the Northstar......they could have kept using it...right?
Pretty reliable...and parts were/are cheaper than Northstar parts

Rippypartsmaster..I have never heard of the Ultra V8...though IMO it should have been part of the 05 STS to keep the car competitive
A next generation V8 should have been smoother, more quiet, more low end torque,2-3 more MPG and at least 50more HP

I also think the GM plant in Tonawanda NY is closed


Warren

Jesda
11-06-10, 10:53 AM
My understanding is that most of the Northstar's problems had to do with manufacturing consistency, especially when it came to head gaskets. True/false?

RippyPartsDept
11-06-10, 12:46 PM
My understanding is that most of the Northstar's problems had to do with manufacturing inconsistency, especially when it came to head gaskets. True/false?

fixed that for you ;)

Jesda
11-06-10, 06:22 PM
LOL! Thanks :D

Will's Fiero
11-26-10, 01:56 PM
My understanding is that most of the Northstar's problems had to do with manufacturing consistency, especially when it came to head gaskets. True/false?

My *opinion* is that GM management cheaped out on the alloy of aluminum used to cast the blocks. I've completed some graduate coursework in light alloy metallurgy and the problem with the Northstar head bolt threads sounds like stress corrosion cracking to me.

Looking at similar engines from BMW introduced about the same time (M60B30 and M60B40 in '93 530i's and 540i's, respectively), those engines have no such problems. Nikasil is another matter, but they don't have head gasket problems, at least not to the extent the Northstar does. I think it's because BMW chose a better alloy than GM did.