: Post 2000 N*?



bharner
05-26-06, 03:16 PM
Hey All,

I have heard that GM made alot of changes to the post 2000 N*'s. Anyone know the specifics to that?

Thanks

Ranger
05-26-06, 08:06 PM
They lowered the compression ratio just a tad to allow for regular gas. They replaced the flat tappet lifters with roller finger followers which extends the oil change intervals to a max of 12,500 under ideal conditions. They also did away with the plug wires by going to COP (Coil On Plug) ignition. There may be more, but that is all I can think of.

Blown Z
05-27-06, 10:39 PM
Is it 2000 and up Northstars that had these changes? I've read in some other places that it was 2001 or 2002 and up.

codewize
05-28-06, 07:35 AM
No it is 2000 and up. I don't know the specifics if these but they also addressed the oil usage issue and coolant leaks that were notorious on the earlier N*.

Eric
05-28-06, 11:39 AM
Seville year by year at: http://www.caddyinfo.com/sevilleyearbyyear.htm

Yaemish
05-28-06, 02:59 PM
Does the head gasket problem still exist in the newer engines?

Ranger
05-28-06, 03:49 PM
Does the head gasket problem still exist in the newer engines?
I think in 2000 or there abouts, they made some changes to the head bolts to reduce the possibility.

JimD
05-28-06, 04:04 PM
Does the head gasket problem still exist in the newer engines?

We could all benefit by a tiny terminology change here. Some very high percentage of head gasket failures can be traced back to an owner's failure to follow the recommended coolant maintenance schedule.

Maybe the head gasket situation could be more accurately described as the "owner did not read the manual" problem?

codewize
05-28-06, 08:14 PM
I concur :contract:


We could all benefit by a tiny terminology change here. Some very high percentage of head gasket failures can be traced back to an owner's failure to follow the recommended coolant maintenance schedule.

Maybe the head gasket situation could be more accurately described as the "owner did not read the manual" problem?

El Dobro
05-30-06, 01:58 PM
Maybe the head gasket situation could be more accurately described as the "owner did not read the manual" problem?[/QUOTE]
And what problem would that be?

codewize
05-30-06, 08:21 PM
Apparently there is a high rate of head gasket failure on the Northstars. In addition this failure is primarily due to lack of maintenance to the coolant system as specified in the owners manual.

I don't really understand why older coolant would affect a head gasket but it does. And the coolant maintenance IS in the owners manual.




Maybe the head gasket situation could be more accurately described as the "owner did not read the manual" problem?
And what problem would that be?

bharner
05-30-06, 08:23 PM
sorry ive been out of it. thanks for the info gents

El Dobro
05-31-06, 03:55 PM
Apparently there is a high rate of head gasket failure on the Northstars. In addition this failure is primarily due to lack of maintenance to the coolant system as specified in the owners manual.

I don't really understand why older coolant would affect a head gasket but it does. And the coolant maintenance IS in the owners manual.

Finally convinced the dealer to change mine at 4 years and 55,000 miles. A lot of Northstars had to have the gaskets changed at even less, so how would that be due to lack of maintenence?

blb
05-31-06, 05:29 PM
Does the head gasket problem still exist in the newer engines?
The thread pitch on the headbolts was changed to a more coarse thread in 2000, and this was supposed to address the premature headgasket failure prevalent in prior Northstars, but according to my contact at the dealer, they still see quite a few 2000 and newer models that have headgasket issues. In April, they had a black '02 STS in with 93,000 miles where the back bank headgasket was breached causing coolant to enter the exhaust.

codewize
06-03-06, 10:32 PM
So is lack of coolant maintenance the cause or the catalyst? Or is this just a problem?

chevelle
06-03-06, 11:03 PM
The head bolt thread pitch change to 2mm pitch threads actually happened mic-2004 model.....

codewize
06-07-06, 02:47 PM
So do we still believe that lack of coolant changes attributes to the failure? And if so, why is that.

JimD
06-07-06, 03:11 PM
Mostly because the corrosion inhibitor chemicals are consumed.