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3.8 vs. 5.3 (Rep)

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nathangartz

nathangartz

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So as we all are well aware, the 3.8L engine in all our GT and GTP's from 97-03 were great engines. At least, I think I can speak for everyone on that topic. If you've ever sold a GP, or any GM with a 3.8, you've probably stated to the prospect that the engine was one of GM's more solid engines (:th_laugh-lol3:cough 3.4!:th_laugh-lol3:)

While I wait for a few people to come over to buy my 97 GT and my 2000 GTP, I wonder if I should be buying the GXP. I haven't really done the research about the 5.3 and I am just wondering what you guys think. Is it as stable and reliable as the 3.8? Will it ever be as reputable as the 3.8? My father works at an auto auction (been a mechanic for 30 years now too) and knows his stuff; however, he hasn't really heard too much about the 5.3 besides the fact that the dealers at the auction expressed some concern about the aluminum block.

How about the trans? Is that the weak spot?

Just looking for some feedback before the light turns green on my sales for my two cars...and I am stuck with no transportation until I pick up my GXP...
 


Hello. There is no doubt about how great the 3.8 is. Had several of them go to 300,000 miles. As for the GXP and the 5.3 LS4 it seems to be a great motor. The Water Pump is expensive when it goes out. It is different the the normal LSX motor's water pump to make it fit into the W-body plat form. And also the Serp belt looks to be a pain and there is some special tool for it. I havent read about any blown motors yet. There was some issue with guys using N2O bout a month ago with number 7 plugs. Biggest issue is finding performance parts designed for the motor. The trans is the weak spot in my mind. It seems hit or miss. Some people are nice and they have failed before 30K others run them hard and replace them around 100K. However the trans is updated with some better hard parts and with a little aftermarket /GMPP they should be pretty good.
 
nathangartz said:
So as we all are well aware, the 3.8L engine in all our GT and GTP's from 97-03 were great engines. At least, I think I can speak for everyone on that topic. If you've ever sold a GP, or any GM with a 3.8, you've probably stated to the prospect that the engine was one of GM's more solid engines (:th_laugh-lol3:cough 3.4!:th_laugh-lol3:)

While I wait for a few people to come over to buy my 97 GT and my 2000 GTP, I wonder if I should be buying the GXP. I haven't really done the research about the 5.3 and I am just wondering what you guys think. Is it as stable and reliable as the 3.8? Will it ever be as reputable as the 3.8? My father works at an auto auction (been a mechanic for 30 years now too) and knows his stuff; however, he hasn't really heard too much about the 5.3 besides the fact that the dealers at the auction expressed some concern about the aluminum block.

How about the trans? Is that the weak spot?

Just looking for some feedback before the light turns green on my sales for my two cars...and I am stuck with no transportation until I pick up my GXP...
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It al depends on what your looking for out of a car. I have a Modded 07 Sc GP GT and take GXP for walks all the time, in my opion they are pretty slow.
 
^^ Looks like i got my work cut out for me then hahahha! When i have my GXP modded up to what power im lookin for ill let you know when i cross a GTP :P Im going to TRY to hit 400 whp if i can.


I have had my GXP for about 3-4 mo now...glad i got this over a g35 or a IS250. Much happier with this faster choice.
 


We've seen a lot of LS4 issues over on NAIOA. One weird issue is the belt tensioner keeps breaking and that requires dropping the engine and cradle to get to.

Not to say it's more problematic than the 3800, but it does have its own set of quirks.
 
well I hope my list of mods can smoke one. Im not lookin to be the fastest or i would have bought an sti for 2k less lol. once my mod list is done ill run one at a track see how i do! Ill be doing cams as well, not sure how many LS4s are cammed out there lol
 
Cams? It is a pushrod motor just like the 3800. CAM, as in one ;)

LS4's aren't good modding motors IMO...the transmission doesn't like to be raped on and the intake side of the motor is very restrictive. IF I were to get another car that is powered by the L67 or L32, I'd spring for a '01 GTP OR a '04 Comp G GTP. With the right mods, no matter what you do to a GXP/SS or anything with the LS4, it is gonna get beat by the supercharged motor for the most part. What I DO like about the LS4 is the exhaust note and the crazy V8 low end torque. IF my 3800 sounded like a GXP...I'd keep it forever :D
 
Personally it came i love the SC 3800's but i got a good deal on a used 2008 GXP, Had good power, warenty, and one thing a 3800 will never a V8 Rumble. Not everyone wants the fastest car i know GASP... haha. But for a UNIQUE car the GXP is a great family car. Less than 16K built in four years. Again i love the 3800/GTP/Comp-G's but they are not exactaly rare. That is one thing that to me makes me love my car. Also Go fast parts are cheaper for the 3800 but as far as the GXP goes you get 12.7" rotors, 18" wheels, Bilstien shocks.(part of the FE4 package) All this adds up to a great base of parts that with a good stock power level make a great DD, and a decent platform to add some power(just not cheap)
 
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Panther427 said:
Personally it came i love the SC 3800's but i got a good deal on a used 2008 GXP, Had good power, warenty, and one thing a 3800 will never a V6 Rumble. Not everyone wants the fastest car i know GASP... haha. But for a UNIQUE car the GXP is a great family car. Less than 16K built in four years. Again i love the 3800/GTP/Comp-G's but they are not exactaly rare. That is one thing that to me makes me love my car. Also Go fast parts are cheaper for the 3800 but as far as the GXP goes you get 12.7" rotors, 18" wheels, Bilstien shocks.(part of the FE4 package) All this adds up to a great base of parts that with a good stock power level make a great DD, and a decent platform to add some power(just not cheap)
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VERY well put my friend. I owe you a beer:th_thumbsup-wink:
 


thanks for all the replies.

Not really interested in doing any modding so I don't have to worry about that. Just want that V8 rumble and a good looking family car.

Mainly interested in what you all have seen as far as common problems.

Sabrewings said:
One weird issue is the belt tensioner keeps breaking and that requires dropping the engine and cradle to get to.
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Sabrewings, thanks for bringing that up! That sucks big time! Any aftermarket replacements that work better? Is it the tensioner itself, the arm, or a weak point somewhere else?
 
I don't know about replacements. Everyone I know of had it done under warranty so I don't think anyone has looked into it.
 
I havent herd of that on the GP cars. Some issues with water with the sun roofs. Some people wear out the brakes quickly.
 
Panther427 said:
I havent herd of that on the GP cars. Some issues with water with the sun roofs. Some people wear out the brakes quickly.
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Massive Cross Drilled and slotted rotors will do that from the factory :th_winking: I wish the '97-'03 GP had good brakes...or at least the 12 inchers like the Monte or Impala...
 
bluegtp91 said:
Massive Cross Drilled and slotted rotors will do that from the factory :th_winking: I wish the '97-'03 GP had good brakes...or at least the 12 inchers like the Monte or Impala...
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For sure, to me i dont consider that an issue, but it sure makes some people angry. I have always been hard on brakes so to me its the price of having performance breaks. But on the other side of the coin, i dont think the breaks wear out that bad for most people, and i havent had to replace mine yet. Good brakes and good tires are the best safety devices u can have on your car.
 


nathangartz said:
So as we all are well aware, the 3.8L engine in all our GT and GTP's from 97-03 were great engines. At least, I think I can speak for everyone on that topic. If you've ever sold a GP, or any GM with a 3.8, you've probably stated to the prospect that the engine was one of GM's more solid engines (:th_laugh-lol3:cough 3.4!:th_laugh-lol3:)

While I wait for a few people to come over to buy my 97 GT and my 2000 GTP, I wonder if I should be buying the GXP. I haven't really done the research about the 5.3 and I am just wondering what you guys think. Is it as stable and reliable as the 3.8? Will it ever be as reputable as the 3.8? My father works at an auto auction (been a mechanic for 30 years now too) and knows his stuff; however, he hasn't really heard too much about the 5.3 besides the fact that the dealers at the auction expressed some concern about the aluminum block.

How about the trans? Is that the weak spot?

Just looking for some feedback before the light turns green on my sales for my two cars...and I am stuck with no transportation until I pick up my GXP...
Click to expand...

Umm GXP All The Way Dude But Seriously if your gonna waste that much coin get a G8 I Love my 2006 GXP but I wish I would have Waited, Plus Pontiac is in the trash in GM's Mind so Why Waste the Money on **** that GM did'nt care enough about Buick in my opinion should hve been cut not there Iconic Car Brand like Pontiac, But who am I a GM guy Disapointed well im off Ford looks Promiseing J/k
 
Plus most GXP MOD Bashers Can't Afford one so they wil never know an they are RARE they will be lucky to Race one with a driver that has the balls to make the GXP move, Too much Supercharged BS on this site, most have probly raced the guy that dosen't have the motor but has Emblems from Ebay People ar stupid sometimes
 
SJR GXP said:
Plus most GXP MOD Bashers Can't Afford one so they wil never know an they are RARE they will be lucky to Race one with a driver that has the balls to make the GXP move, Too much Supercharged BS on this site, most have probly raced the guy that dosen't have the motor but has Emblems from Ebay People ar stupid sometimes
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Really? Get off your high horse. The GXP is a turd compared to modded GTP's. Reason being no one mods them is because there is NOTHING THERE FOR IT besides a few bolt-ons. I LOL'ed at the "affording" part too. Just becuase I didn't buy a GXP Grand Prix, doesn't mean I couldn't have afforded one. Reason I didn't buy one is because of the lack of aftermarket support in the first place. Isn't it funny how even the TURBO V8 GXP can't even muster an 11 second 1/4 but a bolt-on turbo 3800 V6 will throw down 11's all day? Oh, and it does it for about half the price.

And for the supercharged BS...then don't come around since most EVERY Grand Prix on here is Supercharged. And I have raced PLENTY of GXP's, Monte Carlo SS', Impala SS'...and they get walked...and not by car lengths, but by bus lengths. I'll gladly take the trip to Denver to video tape a race between us. Show you have awesome your rare car is. Oh...and what have you done to your GXP? Intake, Cutout, Exhaust, MAF? Guess what. Still nothing great. All the other GXP guys on here are cool to all the other GP owners...why do you have to bash everyone that doesn't have a GXP?
 
I like both cars, cant we all get along?? lol as i said b4 i could have gotten an sti for SEVERAL thousands less....but i didnt because i saw my GXP and loved it.... aftermarket may be limited buuut it leaves me to go to some kick ass custom shops here in scottsdale az and get some performance ;)
 
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