Thread: Central FL - Somehow ended a GP CompG owner.

Hello everyone, my name is Big Al and I like to party!

I am in Central Florida, outskirts of Orlando, and today I became the owner of a 2005 GP. Before visiting this forum, that is all I knew about the car. I have been a motorcycle only owner for a while, but suddenly I needed a car in short notice and a friend that has been drooling over my Harley for a while made me a trade offer. I said yes before I knew what the car was. (yes, that desperate)

Well, here is the car.








Previous owner installed some cherry bomb looking exhaust, as soon as I can I want to put OEM's back, I hate cabin noise, and these are louder inside than outside the car.



I drove it 100 miles home, got 27.4 Avg MPG according to the vehicle running on 93 octane.

There are a few cosmetic things I want to take care of, but new tires come first, then I need to find out the best way to cool it off, runs way too hot, either a new thermostat (180deg?) or comp reprogram? This is going to be a daily driver for me, so all running and mods will be for that purpose.
From all the reading I have done in the forum so far, I gather it is a 2005 GP GTP CompG. It has 103K miles on it. Missing the OEM stereo. So all the warning lights are on. feels like it needs a front end alignment and maybe a hub replaced.

Tranny is shifting as expected for the cars age and milage, but I want to do preventive maintenance to keep it going good. I gets hot down here, so I really have to cool this car off.

Any recommendations on synth oil?

Any and all recommendations will be listened to. Also please ask any questions and I will answer them to the best of my abilities. I am new to GP's, but I used to dismantle and reassemble my 88-98 Silverado's for fun, so Once I feel comfortable with the car, I won't be afraid to tear into it.

Very respectfully,

Big Al

very nice. welcome to site. you shall find plenty of greant and all info here. and oil i use valvoline syn power full synthetic

dual glass packs must be horrible sounding for sure. i dont see a resonator under there, if its not there put one of them glass pack in its place, then get the stock mufflers back on.

comp G too. looks like the hood needs some buffing or something, was it parked under a tree for a while? other then the hood it looks pretty clean.

lots of info to be found here. trans service, and almost anything else it may need. dont use platinum plugs when you do a tune up on it. use iridium plugs.

you need a harness for the radio so all the door chimes and stuff works again.

and how hot is it running? these car like to run hot, 200 to 220 is kinda normal. fans dont come on until 212 deg's. if its rising and falling while driving it could have air trapped in the engine, theres a bleeder on the t stat housing.


and dont cheap out on gas, buy 91 or 93 or higher only. 87 will kill the engine over time. supercharged cars love super/premium fuel.

in my book, oil is oil, as i change it every 3,000 miles. i cant see spending all that extra cash on oil. and i dont buy its good for 5,000 to 10,000 miles either, oil still gets dirty. filter is dirty for sure way before them 5,000 to 10,000 miles are up too.

Pretty much what he said ^^^

These motors are pretty stout, do the regular oil changes and your fine.

As for your hood, you could get away with just vinyl wrapping it with gloss black vinyl, if you can't restore it with a compound. $75-100 for vinyl.

Do the spark plugs and wires, flush the coolant and do a trans fluid change (possibly install shift kit while your at it) and you should be good for another 100,000 miles.

By the way that front bumper is an aftermarket one.

There's a few guys in Florida. We never do any meets. But machine gun squid and myself are in the Daytona area he has a white gtp that looks nice thanks to me. I Rick a fiesta atm.

Originally Posted by Big Al Knine

thank you for the comments.

The hood's clear coat is gone. from what it looks like it is either a bad paint job, or because of running hot during hot weather, it was 98deg today while driving it home. also the heat shield under the hood looked to be a little damaged from heat.

Can you tell me what a normal fluid temp for the tranny is?

about the car stereo: I have not looked behind it, but I assumed that who ever installed it used a correct harness for it, I mean, why wouldn't you? Crappy car audio installs are a pet peeve of mine. I will remove the radio tomorrow and take a look at the wiring. in case it is just hard wired back there, what harness do I need to make sure all my electronics work correct with after market radio, cause right now, all of my sensor warnings are lit up.

I've seen mine run up to 240* but on average day I run around 195-202*. I have my radiator fans set to kick on at 185*.

You will need the Axxess GMOS-04 wiring harness kit. If you want the steering wheel controls you will need a PAC steering wheel kit, I forget which one I think SWI-RC.

What warning lights do you have on the dash?

Originally Posted by Big Al Knine

Aftermarket as in "a replacement to the OEM one but looks the same", or as in "looks different than the OEM one" I know nothing of this cars, so I don't know what it should look like "stock" I do know that it is not a really good paint job on it. at some point someone wrecked the front and painted it, and thats probably what happened to the hood. It looks stock with labels and everything but the clear coat is all gone on most of it, while the rest of the car's Original paint is still blinging.

Aftermarket bumpers are different in they couldn't get the licensing rights to stamp in the Pontiac Arrow between the grilles and the Pontiac letter just below the drivers light. So it has been replaced.

Originally Posted by Big Al Knine

Resonator? where should it be? towards the center of the vehicle there is a round chamber that I thought It was a Catalytic Converter, is that what you are talking about?

You have your stock resonator, the Cat is up on the downpipe. so it goes cat then resonator, then mufflers.

I notice the tips are gone on the stock mufflers, make sure you get some tips on those to push the exhaust out just past the bumper line because from my past experience with mufflers on this car is if you have no tips and the exhaust is exiting right under the trunk, it will be just as loud.

ditch the stock air box, make your own intake, a open cone will let you hear the supercharger whine. f k and N too, not worth it. you can make your own for about what a k/n goes for. about 35 bucks. theres a how to for that also lol

if you have the stock res and its still solid, leave it. a glass pack in its place does the same thing, not really a performance upgrade, its just flat out cheaper to buy a glass pack.

the fans you need to have the pcm tuned to turn on at a lower temp, a 180 t stat is worth less with out the fans being tuned. this can only be done with a tuning program. via a local or a caned tuned pcm from a vender, dealer wont do it that for sure.

this is a 32 inch glass pack i installed on my car, the stock res rotted out, this cost 25 bucks, then 10 for the flange,another 10 to get it welded on the glass pack. 50 vs over 100 for the same thing. priceless.

you got people in Fl that tune. members from here. post in the regional section for a tuner. some one will pop up or direct you to someone.

just how hot is it running? up to 220 is kinda normal. the fans dont come on till 212 and then high speed at 221 or some crap, so they like to be that hot.


sc pick up? that must have been a wheel smoker for sure, any pics or vids of that? sounds like a cool toy.