Thoughts on an '04 Bonneville SLE or GXP?
Once my Monte Carlo is paid off, I need a more family-oriented sedan to add to the fleet to accomodate my newborn son, and to garage the Monte during the winter. 
I was considering the later model (2004, 2005) Pontiac Bonnevilles, but I've been hearing a bit of a rap-sheet on the GXP models, and I was hoping for a little more "oomph" than the Series II 3.8 N/A that comes in the SE and SLE models, and the Supercharged 3.8L SSEi from 2003 doesn't carry the styling I'm looking for. I believe the styling on the Bonny GXP and SLE are slick as **** and you can get them from anywhere around $8,000 with 50k miles.
Anybody here have any thoughts about complimenting the MC with the Bonneville, experience working / driving with them, knowledge of issues,etc.?
The main beefs I heard about the GXP were about the Northstar motor eating oil and gas, blown head gaskets, overly compplicated motor, and for bonnevilles in general: water leaks, "eating transmissions for breakfast", a weird 'shimmy' that happens between 65 and 72mph that cannot be fixed, rear doors being sand-blasted by debris from the front wheels...
Can anybody substantiate the above problems?

I was considering the later model (2004, 2005) Pontiac Bonnevilles, but I've been hearing a bit of a rap-sheet on the GXP models, and I was hoping for a little more "oomph" than the Series II 3.8 N/A that comes in the SE and SLE models, and the Supercharged 3.8L SSEi from 2003 doesn't carry the styling I'm looking for. I believe the styling on the Bonny GXP and SLE are slick as **** and you can get them from anywhere around $8,000 with 50k miles.

Anybody here have any thoughts about complimenting the MC with the Bonneville, experience working / driving with them, knowledge of issues,etc.?
The main beefs I heard about the GXP were about the Northstar motor eating oil and gas, blown head gaskets, overly compplicated motor, and for bonnevilles in general: water leaks, "eating transmissions for breakfast", a weird 'shimmy' that happens between 65 and 72mph that cannot be fixed, rear doors being sand-blasted by debris from the front wheels...

Can anybody substantiate the above problems?
Hi Member (no name in your profile) 
Below is a site I use to check on different Brands/models.
I hope it helps you...
It contains a lot of good infor + reliability reports + consumer reports.


View more photos

Below is a site I use to check on different Brands/models.
I hope it helps you...
It contains a lot of good infor + reliability reports + consumer reports.
2005 PONTIAC BONNEVILLE


- 2005 Pontiac Bonneville Detailed Pricing and Specifications - MSN ... <Click Here for Site
autos.msn.com/research/.../overview.aspx?...pontiac...bonneville...2005
Read reviews of the Pontiac Bonneville, browse used car listings from Auto Trader. Get used car prices from Kelley Blue Book. View specs, pictures, and more.
Once my Monte Carlo is paid off, I need a more family-oriented sedan to add to the fleet to accomodate my newborn son, and to garage the Monte during the winter. 
I was considering the later model (2004, 2005) Pontiac Bonnevilles, but I've been hearing a bit of a rap-sheet on the GXP models, and I was hoping for a little more "oomph" than the Series II 3.8 N/A that comes in the SE and SLE models, and the Supercharged 3.8L SSEi from 2003 doesn't carry the styling I'm looking for. I believe the styling on the Bonny GXP and SLE are slick as **** and you can get them from anywhere around $8,000 with 50k miles.
Anybody here have any thoughts about complimenting the MC with the Bonneville, experience working / driving with them, knowledge of issues,etc.?
The main beefs I heard about the GXP were about the Northstar motor eating oil and gas, blown head gaskets, overly compplicated motor, and for bonnevilles in general: water leaks, "eating transmissions for breakfast", a weird 'shimmy' that happens between 65 and 72mph that cannot be fixed, rear doors being sand-blasted by debris from the front wheels...
Can anybody substantiate the above problems?

I was considering the later model (2004, 2005) Pontiac Bonnevilles, but I've been hearing a bit of a rap-sheet on the GXP models, and I was hoping for a little more "oomph" than the Series II 3.8 N/A that comes in the SE and SLE models, and the Supercharged 3.8L SSEi from 2003 doesn't carry the styling I'm looking for. I believe the styling on the Bonny GXP and SLE are slick as **** and you can get them from anywhere around $8,000 with 50k miles.

Anybody here have any thoughts about complimenting the MC with the Bonneville, experience working / driving with them, knowledge of issues,etc.?
The main beefs I heard about the GXP were about the Northstar motor eating oil and gas, blown head gaskets, overly compplicated motor, and for bonnevilles in general: water leaks, "eating transmissions for breakfast", a weird 'shimmy' that happens between 65 and 72mph that cannot be fixed, rear doors being sand-blasted by debris from the front wheels...

Can anybody substantiate the above problems?

Joined: Apr 2010
Posts: 12,601
From: Mentor, Ohio
I too like the Bonnies, they are nice cars, good stance, aggressive look and nice ride/handling. As for the N* engine, I haven't followed them much. I know there are earlier N* that had some issues but I thought I heard at a certain point GM improved on the design and ended some of those problems.
If you are looking at a Bonnie with a N*, perhaps check a forum like PontiacBonnevilleClub.com or hit a Caddy forum and see what people are saying about that N* engine.
Best of luck on deciding what to go after.
If you are looking at a Bonnie with a N*, perhaps check a forum like PontiacBonnevilleClub.com or hit a Caddy forum and see what people are saying about that N* engine.
Best of luck on deciding what to go after.
I've been doing a lot of reading on the Northstar engine and good god, it scares me. I could take one or two bad reviews and brutal beatings against it, but more people say "run away" than even "It's ok" more or less "It's reliable". Granted, a lot of these bashings are from pre-2004 Northstars before the headgasket "fix", but at any rate, it sounds like it should just be avoided all together.
What I think I will do instead is get the Bonneville SLE with the Series II 3800, make it my daily. The SLE has the style I'm looking for and the powerplant I trust. At the same time, I could try taking my hand at super/turbocharging the Monte. If I'm successful, I can apply the same do-up to the Bonnie and have the over-all style, utility, and power that I'm looking for.
What I think I will do instead is get the Bonneville SLE with the Series II 3800, make it my daily. The SLE has the style I'm looking for and the powerplant I trust. At the same time, I could try taking my hand at super/turbocharging the Monte. If I'm successful, I can apply the same do-up to the Bonnie and have the over-all style, utility, and power that I'm looking for.
A real good buddy of mine has a 03 bonnie ssei he has done some little visual mods (lowered etc) it is an intercooled gen v setup on rockers. Stock bottom end stock heads stock cam with a built trans and he is making 326whp and runs 12.60 on the 1/4 mile. Its a beautiful car. Don't know much about the northstar other than its nickname is the deathstar, Heard there nothing but issues.
^ You are wise for doing your homework instead of getting something & finding 'out that it has a bad history & problems.
Thanks for your reply & to the member's that posted some good advice. Good Luck on finding what you want & can enjoy.
Thanks for your reply & to the member's that posted some good advice. Good Luck on finding what you want & can enjoy.
in case anybody was curious about the Northstar problems, this forum spelled it all out very clearly with multiple 1st-hand accounts of failures:
4.6 V8 Issues?
4.6 V8 Issues?
in case anybody was curious about the Northstar problems, this forum spelled it all out very clearly with multiple 1st-hand accounts of failures:
4.6 V8 Issues?
4.6 V8 Issues?


















