Cadillac Owners Forum banner

Northstar years - good and bad ?

64K views 22 replies 10 participants last post by  Submariner409 
#1 ·
I have owned 4 98-99 Auroras and a 2001 Eldorado ETC. I have never had any problems with overheating on any of them. Of course I am aware of the headbolt problem and I know there were certain design changes in 2000 and 2004 (am I correct here?).

But recently I have seen a couple of places on the internet that suggests the worst years for this headbolt problem is 1997-1999. I am not aware of any design change pertaining to head clamping that happened in 1997, that would suggest the earlier Northstars are more reliable in this area. Has anyone else heard of this or know what they may be referring to?

It is hard to fathom that all 1993-1999 Northstars were susceptible to this problem. I does make more sense that something happened in 1997-1999 that it took until 2000 for the problem to be first addressed. It this problem was widespread since 1993, why would it take so long for GM to address this expensive warranty problem?

So, is there something superior about the headbolt design of 1993-1996 that changed in 1997?

 
This post has been deleted
#6 ·
Rumor has it there were 3 aluminum alloy metallurgy changes - around 97 or so, again for 2000 - but no one has come up with positive proof.

Read through the "Root cause ..........." sticky ^^^ and see if some of AJ's pictures of messed up bolt holes are still there.
 
#11 ·
I find it unfathomable that someone would spend $30-$50K on a car and not maintain it. A Cadillac is not a 1962 Ford Fairlane or a 1997 Toyota Camry. I do not have the guts to buy cars from these auctions. I have never bought any of the 68 cars I have owned from a dealer, always from a private party. I guess that must be why I never had an issue with any Northstars yet (knock on wood).

Most original owners of Caddys I have personally dealt with have kept meticulous maintenance records and tended to be a bit obsessive/compulsive about their cars.

----------

However Dexcool notwithstanding, I find it hard to believe that the infamous Northstar head bolt/head gasket/oil leakage problems can be attributed to poor maintenance as a whole. These problems are not inherent to say a LT1 or a 3800 V6 etc.
 
#12 ·
I find it unfathomable that someone would spend $30-$50K on a car and not maintain it.
Not uncommon. Many people simply trade them off before the problems manifest themselves and let the next guy worry about it.

I remember when I bought my first Cadillac (many, many moons ago), my neighbor (a Chicago cop) always had a nice Eldorado. We where talking one day and I was admiring his '72 or '73 Eldo. He had about 40K on it and told me he had never changed the oil. :shocked2: But it would be traded off before he had any problems with it.
 
#13 ·
I guess that is why I go broke! I treat every car like I am going to keep it for 100 years, heck I even put on new Michelins just before I sell them too! I have always changed my oil every 2000 miles and changed anti-freeze every 3 years (I seldom keep a car that long though, I get bored easily).
 
#16 ·
I have always changed my oil every 2000 miles
Waste of time, money, and resources.

You would hate me - I change the oil/filter in the STS each March or April, mileage be damned.

Because the car has become a garage queen it seldom sees more than 5,000 miles/year, so I'm nowhere near the 10,000 - 12,500 OLM allowance.............. but when it runs, it RUNS. Did a couple of my airstrip WOTs to 120+ last week. The thing loves it, especially the weird twisty farm country roads east of here.

This isn't 1954 any more .................
 

Attachments

#15 ·
It is ironic who these cars were originally marketed for when the perfect customer for a Northstar would be someone who likes to tweak, maintain, customize and drive the living crap out of them. Instead most owners drive them sparingly, short distances and only to church on Sundays, and the grocery store on Senior discount days.
 
#20 ·
I know this is a few days old but I wanted to bump this to add my two cents. As far as the "best" years for the Northstar, IMHO, anything after the 2000 design change is superior to pre 2000's in every area except possibly the exhaust port and valve size. Even taking this into consideration, GM was still able to get 300HP out of the L37 with lower compression and smaller valve size. Both transverse engines have significantly smaller cams than 93-99 engines helping emissions and fuel economy. In fact the L37 cam is darn near the size of the 93-99 LD8 cam and makes 25 HP more. That's efficiency ! I imagine the post 2000 L37 has a torque curve similar to the old LD8 making it a stronger motor that is more "streetable" than the old L37 and the LD8 is definitely stronger in the lower RPMs than it used to be. For individuals also looking for more power, the larger exhaust valve from and LH2 and a compression bump back to 10.5:1 will increase power by 20-25HP minimum.
If you are looking for performance reasons, the overall "best" (my) vote goes for 2004-2005 and with 2006 and up getting honorable mention but specs and design changes are hard to find. I like post 2004 because the thread pitch on the head bolts was changed and virtually eliminates head gasket issues.
In answer to your thoughts on head bolt failure, it should be noted that almost all head gasket failures can be traced to the customer rather than a design flaw. Failing to use premium fuel in the early versions, changing oil when the stupid oil monitor tells you ( instead of at the proper mileage interval ), and put-putting around all contributed to scary combustion chamber events with damaging cylinder pressure. ( that pressure has to go somewhere if the valves aren't open yet, head gasket is the path of least resistance). Coolant also breaks down over time and needs to be maintained as well. Regardless, consumers fail to take responsibillity for their part and Cadillacs are expensive cars so GM had to bite the bullet on warranties. Out of warranty repairs were expensive so the engine got a bad rap publicly. I currently have 150K original miles on my 05 LD8 with zero problems.
Since the P07 PCM (04-05) is now tunable ( Madtuner.com), it is possible to do DIY mods and have it tuned properly. 2006 and up, and all LH2 engines, have the excellent E67 PCM which has been tunable for years. Virtual all mods would have to be DIY.
Headers are cake for any serious hotrodder , however, the crossover pipe remains the limiting factor for exhaust related power increases. The diameter of the pipe ( it's a LOT smaller than it looks when you pull the heat shield off ) is too small for a 300HP engine. This means a fair amount of power was left on the table, regardless of popular mythology that the factory combination was "maxed out " . Like many before me, I am trying to figure out some form of DIY solution but their really isn't much wiggle room. Running the maximum size pipe that will fit between the block and the transaxle, combined with high tech coating and modern ( and very thin) heat shielding materials like the turbo tuners use, would allow the pipe to make contact with the block and transaxle without fear of unsafe heat transfer. Technology has come a long way since 2000 and light years ahead of 1993 when this pipe was originally conceived.
Reground cams are certainly a reality now, with modern CNC machines and heat treating processes, there should be no worries about early lobe failure. Now if I could just get one of the companies on the internet that advertise the service to respond. ( Please don't reccommed a popular Northstar performance company, they don't "like" the 2000 up engine, don't seem to understand the difference between a lifter and a hydraulic lash adjuster and quoted me almost double what their website lists for this service. They also offer head porting but can't seem to provide before and after flow numbers which makes it hard to drop a large amount of cash for an unknown. If they want to work with ancient technology that leaves a minimum of 25 HP on the table just from factory efficiency upgrades, that's their prerogative.)
That's it, that's my two cents, hope it helps.
 
#21 ·
I have owned 4 98-99 Auroras and a 2001 Eldorado ETC. I have never had any problems with overheating on any of them. Of course I am aware of the headbolt problem and I know there were certain design changes in 2000 and 2004 (am I correct here?).

But recently I have seen a couple of places on the internet that suggests the worst years for this headbolt problem is 1997-1999. I am not aware of any design change pertaining to head clamping that happened in 1997, that would suggest the earlier Northstars are more reliable in this area. Has anyone else heard of this or know what they may be referring to?

It is hard to fathom that all 1993-1999 Northstars were susceptible to this problem. I does make more sense that something happened in 1997-1999 that it took until 2000 for the problem to be first addressed. It this problem was widespread since 1993, why would it take so long for GM to address this expensive warranty problem?

So, is there something superior about the headbolt design of 1993-1996 that changed in 1997?

What about 1993-96?????
 
#23 · (Edited)
Welcome to CF !!!

Please read the non-scientific poll on Northstar engine/gasket failures in the stickies in Engines; Northstar. Stickies, marked with a push pin, are necessary, timeless info in any forum of interest.

1997 - 1998 - 1999 had block metallurgy troubles, 2000 had head bolt thread length problems.

Here - I'll do some of your homework - open this link, scroll down the poll to "View results" in the bottom right of the poll page.

 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top