: 2000-2005 Headgasket...



Reloth
02-14-08, 05:07 AM
So I'm deployed right now and have a 97 deville sitting at home with what i think is a blown head gasket...If this is the case ill be getting a new car when i get home.

My question is, did Cadillac ever fix this problem with their newer cars? Or, are the say 2003s in a few years going to start breaking the same way?

Eld01
02-14-08, 07:10 AM
First, Thank You for serving our country. The 2000+ heads were redesigned with longer bolts and are much less likely to blow than the 1999-. If I am not mistaken they also lowered the compression ratio, allowing you to fuel with regular gas insead of the premium that your car requires. Stay safe and God Bless.

dkozloski
02-14-08, 11:33 AM
The headbolt threads are a coarser pitch as well.

Ur7x
02-14-08, 12:17 PM
Pretty sure they didn't get the coarser pitch until MY 2004

Ranger
02-14-08, 01:09 PM
I thought that the pitch and length where changed in 2000.

Thanks for your service and stay safe. :patriot:

Mark C
02-14-08, 01:27 PM
The Bolt lengths were changed for the intake manifold side in 2000, they are shorter than the 99 and before engines. However since they use the same Time-serts as the previous year engines, neither the thread pitch or the length of the threads changed until later (2004?)

Submariner409
02-14-08, 02:43 PM
Somebody had better get the straight dope on head bolts because there's a lot of conflicting info here ^^^. It might cost someone an engine........

1:52 PM, EST: Sit tight.....help may be on the way...............

ewill3rd
02-14-08, 03:49 PM
Not sure about the length but...


This service VME is to alert you to a possible packaging concern on Northstar cylinder head gasket kits. The part numbers affected are 12564795 and 12564796.

This kit comes with a cylinder head gasket and 10 cylinder head bolts. Some of these kits have been packaged with the 2004 style of cylinder head bolt, which has a 2 mm thread pitch. The original head bolt pitch is a 1.5 mm thread pitch. The correct pitch head bolt part number for 2000 to 2003 engines is 12557775. These can be ordered separately if you have a kit that is packaged incorrectly. You should not change the engine block threads to the 2mm pitch, just obtain the correct head bolts.

These kits currently indicate that they fit 2000 to 2004 Northstar engines. This usage is incorrect; it should be 2000 to 2003 for part numbers 12564795 and 96. The 2004 engines are being built with the 2 mm thread pitch. SPO is currently working to correct the usage. To ensure that the kit is correct, they can be ordered as RFI, request for inspection, and have SPO confirm that the kit has 1.5 mm thread pitch bolts in the kit.

Ur7x
02-14-08, 03:51 PM
There are (at least) three different Timesert Kits for North*'s
1) 93-99
2) 2000-2003 and
3) 2004 and beyond

The first two kits use the same inserts which are for 11mm X 1.50mm bolts However the 2000-2003 kit has a different drill/tap to stick the "sert" deeper in the block for the longer bolts

The 2004 kit uses 11mm X 2.0mm bolts (this is the same size bolt as an LS1 BTW)


Read all about it here http://www.timesert.com/html/gm.html

JimD
02-14-08, 06:02 PM
There are (at least) three different Timesert Kits for North*'s
1) 93-99
2) 2000-2003 and
3) 2004 and beyond

The first two kits use the same inserts which are for 11mm X 1.50mm bolts However the 2000-2003 kit has a different drill/tap to stick the "sert" deeper in the block for the longer bolts

The 2004 kit uses 11mm X 2.0mm bolts (this is the same size bolt as an LS1 BTW)


Read all about it here http://www.timesert.com/html/gm.html

Soooo. This smells like an opportunity for an adventurous someone to use a "2004 and beyond" Timesert kit on a 1999 and previous block. The result would be deeper holes, longer bolts and the latest production thread spec's.

Makes me curious about the bolts used in the supercharged version.

Submariner409
02-14-08, 06:17 PM
My thanks to eWill3rd for taking the time to bring the bolt discrepancy to light. I started looking in my FSM (to formulate a reply to the OP) and there were conflicting repair procedures, so I asked him to do a little Sherlock Holmes.

We have all just learned more about the later N*'s. :thumbsup:

Mark C
02-14-08, 06:41 PM
All 20 head bolt holes in a 93 to 99 N* are 1.5MM by 32mm deep. 2000 to 2003 head bolt holes are also 1.5MM with the upper bolt holes being 32mm deep, and the outer (lower) holes being 51mm deep. 2004 and up holes are threaded at 2.0mm. The upper holes are 29mm deep, and the lower holes are 45.5mm deep.

Ranger
02-14-08, 06:53 PM
Kinda makes one wonder why they did not go to the 2.0mm bolt in 2000. :hmm: