Hey guys,

I'm looking at buying a 2004 GXP [real cheap] that needs new head gaskets. It has about 90000 miles, and appears to be in great shape other than the gasket issue. I'm told the engine has to be removed to fix it. I am looking at doing this myself. Are there any threads here that detail the process of doing this?

Thanks and happy new year!

The engine has to be dropped out from the bottom, this involves lifting the body off the subframe, NOT an easy job without a lift, as far as I know I the only one here that has done an engine swap on a GXP without a lift. Definitely not a job I would recommend unless you are very mechanically inclined.

You will want to stud the block for this job, do it once, do it right, and never have to do it again. There are a couple head stud kits out there, any of them are better then the factory bolts.

_________________
Ryan

2003 Bonneville SSEi - The Black Mirror SOLD!
2002 Bonneville SE - The Mutt Complete 2004 SLE interior, drivetrain, and body harness swap, ECC swap, HUD swap, black GXP wheels, GXP headlights and tinted tails - SOLD
2003 BMW 540i M Sport, 2001 BMW X5 4.4i, 2010 GMC Acadia, 2017 Grand Design Imagine 3150BH
1982 Cutlass Supreme - The fun one

Page 3 here begins the engine swap, I was able to pull it out through the top but still had to drop the subframe for access. your-ride-pics-and-videos/topic33445.html

_________________
Ryan

2003 Bonneville SSEi - The Black Mirror SOLD!
2002 Bonneville SE - The Mutt Complete 2004 SLE interior, drivetrain, and body harness swap, ECC swap, HUD swap, black GXP wheels, GXP headlights and tinted tails - SOLD
2003 BMW 540i M Sport, 2001 BMW X5 4.4i, 2010 GMC Acadia, 2017 Grand Design Imagine 3150BH
1982 Cutlass Supreme - The fun one

Thanks for the info and the link! Looks like it is quite a bit of work! I am going to see the car this weekend, and will then decide whether to buy it or not.

Thanks

Bought the car today. The fun begins! I will post a few pictures in a day or two.

One other issue... Both the fuel and temp gauges do not work at all. They show empty and cold all the time. Something in the cluster perhaps?

Thanks

They are known for bad stepper motors for the gauges. When you turn the key on do they sweep?

Anxious to see this project! Even with all the work I have done to my SE and having owned an SLE and SSEi, I still drool over a GXP.

_________________
Ryan

2003 Bonneville SSEi - The Black Mirror SOLD!
2002 Bonneville SE - The Mutt Complete 2004 SLE interior, drivetrain, and body harness swap, ECC swap, HUD swap, black GXP wheels, GXP headlights and tinted tails - SOLD
2003 BMW 540i M Sport, 2001 BMW X5 4.4i, 2010 GMC Acadia, 2017 Grand Design Imagine 3150BH
1982 Cutlass Supreme - The fun one

As I recall, there is no sweep when the key is turned on.

Thanks

No sweep means the stepper motors have kicked the bucket.

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-Car Guy Carl
"Penelope" - 2003 SLE - 247k Miles
"Sydney" - 2000 Honda S2000 - 98k miles

Checked it again this morning, and none of the gauges do a full sweep before coming to rest. They go directly to their position. Not quite sure what this means... The gauges on our 03 SLE do a full sweep and then come to rest.

Confused...

A few pictures guys. We had some nasty freezing rain here yesterday, so there are a few puddles on the floor.

How do you know the head gaskets are bad? Just make sure that is the problem before you start the repairs.

_________________
bobgto65

2004 Bonneville GXP 62,000 miles purchased 04/13
2009 G8 GXP PBM, M6 9580 miles, no mods, sold 08/15
2009 G8 GT SBM 36,000 miles, modded 430 whp
2002 Bonneville SSEi 203,200 miles (sold 3/2014)

Well, add me to that crowd. I think a lot of FORUM members drool over GXP Bonnevilles, especially the nice ones. - BC

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In Memory of Brad - 1/21/1977 .. 10/23/2013 ...... Aaron - 1977 .. 2017 .....
2017 Hyundai Santa Fe Sport ..... 1992 Bonneville SSE 1SB 170 HP L27 4T60E retired/sold to MattStrike ..... 2005 Bonneville SE 1SC 205 HP L36 4T65E - retired/salvage yard ..... PBCF user 2321

Looks pretty clean! Can't tell for sure, but looks like the passenger side head light has been replaced with a non-GXP lamp.

How's the interior?

_________________
-Car Guy Carl
"Penelope" - 2003 SLE - 247k Miles
"Sydney" - 2000 Honda S2000 - 98k miles

What is the difference between the GXP and SSEI/SSE headlight?

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05 GXP Red, 05 GXP White, 03 SSEI, 02 SSEI, Sold 98 SSEI, 98 SE, 98 SLE, 98 SSE

Passenger side is GXP, you can see the glare caps - black.





GXP headlights - HIR bulbs for high beam, chrome in reflector bowl is slightly darker, turn signal reflector bowl is gloss black, and bulb glare caps are flat black.

Standard headlights - regular halogen bulbs for hi and low beams, bright chrome reflector bowl, turn signal reflector bowl is bright chrome, bulb glare caps are bright chrome.

The GXP / '05 SLE headlights just have a darker / more aggressive look to them.

_________________
Ryan

2003 Bonneville SSEi - The Black Mirror SOLD!
2002 Bonneville SE - The Mutt Complete 2004 SLE interior, drivetrain, and body harness swap, ECC swap, HUD swap, black GXP wheels, GXP headlights and tinted tails - SOLD
2003 BMW 540i M Sport, 2001 BMW X5 4.4i, 2010 GMC Acadia, 2017 Grand Design Imagine 3150BH
1982 Cutlass Supreme - The fun one

I'm told by the seller, that the coolant level keeps going down, with no signs of leakage. He said his mechanic added some leak stop stuff to the rad, and that fixed the problem for a short while. His mechanic then told him it was a head gasket issue.

The exterior is dirty at the moment, but is generally in good condition. The are no dents anywhere, just a few scratches. I think most would buff out. Having said that, the is some rust starting around the gas cap door. I will likely have my local body shop repair that.

The interior is in excellent shape! That is one of the things that caught my eye when I first looked at it. The car is fully loaded too, with sunroof, HUD, memory seats and more.

I have discovered a power steering leak, on the high pressure hose, just below the PS pump. It looks like there is a joint in the hose where it appears to be coming from. I suspect it is an O-ring?

One other thing guys.... I have read many times on here that Bonnevillle GXPs have a size 10 engine in a size 5 dress. After looking at the engine compartment for a few minutes, I think you are all wrong! It has a size 12 or 14 engine in a size 4 dress! LOL!!

Yup! Haha I've got 2 Northstars awaiting headgaskets and I don't enjoy the thought of having to do them anymore. It's literslly radiator to firewall, all engine. Well at least you found the power steering leak now. Should be much easier with the engine out as it is to do anything on the northstar.

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Clay
1997.2 40th SLE-138k
1968 Bonneville 400ci w/TH-400-40k
1999 GMC Suburban SLT-191k
2005 Escalade 253k-GINA

Ok, before "ass"uming that it is a headgasket issue, and yanking the heads, and all that labor, if it is losing coolant, but yet no traces can be found it may just be something as simple as the block freeze plugs. This was the issue I had. Sitting overnight, I'd get one or two drops on the floor and of course the wonderful scent of Dexcool. But by the time I'd get it over to my shop, put it up on the lift, and search, there was nothing. What was happening, was that it would drip down after it cooled, then it'd burn off from the heat of the components and exhaust cross-under. It wasn't until I let it sit on the lift overnight, and checked it the next morning that I found it.

If you had a bad head gasket, you'd probably have some form of "milkshake" for coolant, and/or the oil too.

I'm not absolving that it may have a head gasket, issue, just trying to find the simple stuff first. I resorted to a complete flush of the coolant, refilling with just water (per the instructions), then running through a stop leak formula I bought at Napa, ran it for a half hour to cycle it through, then flushing everything out again, and letting it sit 24 hours, before re-filling and pressurizing. It worked and never had a leak after.

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Retired Bonneville Owner and former GM Tech:
2004 Pontiac Bonneville GXP: Black/Ebony *SOLD*

Summer Toys: Combined 827 RWHP / 877lb/ft RWTQ
2004 Pontiac GTO: Impulse Blue Metallic/Black/M6: lots 'o mods, 415 RWHP / 405lb/ft RWTQ!
2006 Cadillac STS-V: Light Platinum Metallic/Light Gray/A6 - Spectre CAI, Magnaflow exhaust, Speed Inc. tune, 412 RWHP / 472lb/ft RWTQ

Daily Drivers:
2019 Chrysler Pacifica Limited: Mommy's new RGC
2015 Chrysler Town & Country Limited Platinum: Kids new RGC
2007 Chrysler Town & Country Limited: Sold to neighbor
2009 Pontiac G8 GT: L76, Sport Red Metallic
2003 Chevrolet Suburban 2500: Doeskin Tan - 8.1L Big Block... new plow truck
1999 Chevrolet Suburban: Sunset Gold Metallic - Daddy's winter beater and plow truck

Thanks for the info. I would image that pressurizing the cooling system to 12-13 PSI through the rad cap and seeing if it drips down, would be a good test too?

The oil looks like it had just been changed, so I'm not sure what signs may be there.

Yes. You could do that way if you have that tool. One of the few I don't as We always had them at the dealership.

_________________


Retired Bonneville Owner and former GM Tech:
2004 Pontiac Bonneville GXP: Black/Ebony *SOLD*

Summer Toys: Combined 827 RWHP / 877lb/ft RWTQ
2004 Pontiac GTO: Impulse Blue Metallic/Black/M6: lots 'o mods, 415 RWHP / 405lb/ft RWTQ!
2006 Cadillac STS-V: Light Platinum Metallic/Light Gray/A6 - Spectre CAI, Magnaflow exhaust, Speed Inc. tune, 412 RWHP / 472lb/ft RWTQ

Daily Drivers:
2019 Chrysler Pacifica Limited: Mommy's new RGC
2015 Chrysler Town & Country Limited Platinum: Kids new RGC
2007 Chrysler Town & Country Limited: Sold to neighbor
2009 Pontiac G8 GT: L76, Sport Red Metallic
2003 Chevrolet Suburban 2500: Doeskin Tan - 8.1L Big Block... new plow truck
1999 Chevrolet Suburban: Sunset Gold Metallic - Daddy's winter beater and plow truck