2005 Pontiac Grand Prix

[Brent_G]

Last week my probe had a messy divorce with its clutch. My truck is currently in mn with my sister so I had to take a car off the lot.

It came from from Las Vegas Adesa auction last week and I was only planning on taking it home for a night. Well needless to say I fell in love with it and decided to keep it.

It's a 2005 gtp with 130k on the clock and the 3.8 supercharged. Absolutely zero rust at all, factory paint marks are still on some of the suspension and everything including the had works.

My knowledge on known problems with these is lacking however besides the usual intake gasket issues which this doesn't have so far. Anything else I should watch for or check out while I have it on a lift tomorrow?

 

[ls1mike]

I have an 04 COMP G GTP. What does the tranny fluid look like? How does it shift? 04 got a bunch of 4T65E updates, maybe Trav will chime in. You shouldn't have an intake gasket problem in that year. Try to see if you can see the frame of the gasket between the heads and the intake. Should be metal.
Blower oil in the snout may need a change.
They ride a little firm. I messed up a rear strut recently hitting a VERY large hole.

. Some of them use oil due to faulty valve seals. Mine does not have the problem and for some reason it seems to affect the N/A ones more often.

Tranny is the biggest thing in these as the Supercharged ones tend to be harder on them because people put their foot in it more and it just has to handle more power and torque. I generally add a aux cooler to all of my 3800 cars.

Can I ask what you paid for it?

 

[cknight49090]

coolant elbows,vc gaskets,wheel bearings,service the trans I am sure there is a couple more things

 

[Brent_G]

Trans fluid looks good but I'm going to dump it tomorrow just to safe. It seems to shift fine and no issues I can tell.

I believe we paid 4300 for it or so but I would have to look for sure.


Ck good idea on the vc gaskets. I smell faint burning oil when the hood is open so I'm going to check them.

 

[ls1mike]

The faint burning is the VC gaskets. Not too big of job, I usually undo the front motor mounts and roll the engine forward using a ratchet strap to get at the rear one. The coils and coil bracket have to come off for the front one.

 

[Trav]

Nice car! The transmission has all the updates and is the best version of the 4T65E HD.
There were no problems with the L32 LIM gaskets.
The engines didn't have any issues at all worth noting, they were also the best version of this iconic engine. A phenomenal engine and tranny package!

With these engines GM really got it 100% right! Shame they canned them in 08 for less reliable and finicky aluminum engines that weigh only 20lb less. IMHO GM took 1 step forward and 2 big steps backward when they discontinued these engines.

Hub bearings can be a sore spot with these cars, on mine when one failed i just replaced all of them with SKF or USA made Timkens, end of problem. Axle nut torque is critical when replacing them!

I want your car to add to my L36 and L67

 

[Brent_G]

Originally Posted By: Trav
Nice car! The transmission has all the updates and is the best version of the 4T65E HD.
There were no problems with the L32 LIM gaskets.
The engines didn't have any issues at all worth noting, they were also the best version of this iconic engine. A phenomenal engine and tranny package!

With these engines GM really got it 100% right! Shame they canned them in 08 for less reliable and finicky aluminum engines that weigh only 20lb less. IMHO GM took 1 step forward and 2 big steps backward when they discontinued these engines.

Hub bearings can be a sore spot with these cars, on mine when one failed i just replaced all of them with SKF or USA made Timkens, end of problem. Axle nut torque is critical when replacing them!

I want your car to add to my L36 and L67

Glad to hear the trans is the updated one, that was the biggest worry for me!

Funny enough we got this car so cheap due to how it was listed. Comments said transmission was out and engine had knock and we planned to swap eng/trans. Got it here and the only thing wrong was seized caliper and serpentine belt was pretty much shredding itself.

 

[PhillyJoe]

Nice car. Welcome to the world of S/C'd Grand Prix. Change the s/c fluid not knowing when/if it was done. I use the sprayer/tube from a windex bottle. Should get 8 ounces out and put back the same. Available at GM dealer for about $20. HD trans in my '07 GT still running strong. Get a filter and fluid for it but hold off on the gasket - mine is like new and I changed the fluid twice.

 

[Brent_G]

Here are some pictures of the beast if anybody is interested

Sorry about the angles, not alot of room inside and it was -35 windchill outside.

 

[Clevy]

Nice car. My friend had a white 06. Fantastic car. I took it out on the 401 and wound it out as often as I could.
They sold it at 300k on the odo with only fluid changes.
And 4300 is a steal. Iirc they got 12000 for theirs even with high miles. Could just be the Canadian premium we pay for vehicles though.
Nice score. I'm jealous.

 

[ls1mike]

Looks clean, headlights look like mine...LOL.

I have had 3 supercharged 3800s love every signal one of them.

Is that your own home shop?

 

[Brent_G]

I've drove a few GTP's over the years that we have had and always liked them. It has a few scuffs and a cracked windshield but underneath is perfect. Not the rusty nightmares we have around here.

The shop is on a piece of land we bought to expand parking and storage for our business. I have my office in the front but besides that it is only used for a place to keep and work on the toys.

 

[PhillyJoe]

That engine compartment looks good as new; no one would guess it had 130k on it. Nice detailing.

 

[Clevy]

You've got a lift.
I'm even more jealous now

 

[ls1mike]

A lift so nice! I have the space, just need to get one at this point. I have Barn outback that has doors now. Plenty of room for a lift, need to run power.

 

[JHZR2]

Always liked those cars... Kind of bummed I never picked one up. Looks like you got a beauty for a deal though!

 

[Brent_G]

Trav, whats your thoughts on the transgo kit? I did notice after a trip it seems to have a bit of a delay between gears (little over a half second i would say). It doesn't slip or hunt for gears and no other problems i can tell.

 

[ls1mike]

I am sure Trav will chime in, but I have use the ZZP one in a few of my cars and I love it! They say it is rougher on hard parts but it really firms the shifts up.

 

[HM12460]

Very nice! Been giving a lot of thought about buying one myself.

 

[Trav]

Originally Posted By: Brent_G
Trav, whats your thoughts on the transgo kit? I did notice after a trip it seems to have a bit of a delay between gears (little over a half second i would say). It doesn't slip or hunt for gears and no other problems i can tell.

I like the Transgo accumulator kit in stock units, It increases pressure just enough to to firm the shifts up and cut the shift times down.

It is not a bang screech kit which can really cause hard shifts, it actually improves unit longevity not decrease it by reducing slippage between shifts which is there even though you may not feel it.
On the scan tool you can see a real difference in shift times. On the road the result is nice smooth and positive shifts with no harshness.

I did one for my friend Frank (Demarpaint) last year, he was getting a CEL for tranny code, shift times were going over the limit.
The kit cut them down from .68 to .23-.35 well with normal and acceptable range.