Is GM's LS4 (5.3 Aluminum V8) a good motor?

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Pontiac is throwing this engine in their new Grand Prix GXP. (it replaces the venerable 3.8 L67).

I understand this powerplant's a derivative of the LS1 and is used in some current GM trucks and SUV's.

Is this LS4 a good engine?? Any issues such as piston slap, high oil consumption, head gasket problems, etc?

TIA
 
I don't know how well this engine will do, but according to the Pontiac website, it's not going into the Grand Prix, but rather the Bonneville. Per the website, as of about 45 seconds ago, the GP still gets the S/C version of the 3.8L, which in Pontiac trim, is good for 260hp. In addition, again per the website, the Bonneville is getting a version of the Northstar V-8, not a version of the small block family. Of course, maybe they haven't updated their own site yet. . .
 
Go to pontiac.com, click on vehicles coming soon, then click on grand prix gxp. The gxp will be available with the aluminum block 5.3, out of the ssr.
 
No, It is not that great of an engine. It's only real advantage is weight! THey used this engine in the SSR and the Trailblazer because the front end could not take the weight of other V8's that theyb have. They also do not have the capacity and are not willing to but higher output engines in these vechile. They would have to redsesign the front structure, transmissions etc....... to use other V8's.

Just look at the SSR's lack luster performance numbers!!

Rest assured that they are going to have to limit the how much power you can apply from a dead stop to keep torque steer in check. They are also going to have some handleing issues. What they really need to do is build these vechiles as rear wheel drives that why engine comprimises are not being made due to transmission and structure limitations!

Truthfuly the high content 3.9 wich is a bigger version of the high content 3.6 would be ideal for both of these vechiles in their current drive configuration. They are not building the 3.9 yet.Even the 3.6 would be good choice. I am sure that they are probably not able to produce enough 3.6's yet to meet their current demands though.

They know that they can not improve fit,finish, materials, handleing,durability etc.... cheaply or quickly! So instead of redesigning yet again to catch up with the industry they are trying to move in a different direction to try to minimize their weak areas. It is easy and cheap for them to shoe horn a larger engine in place. I am sure that they have more production capability then they need for the LS4.

I suspect that the power output has been kept low on this engine due to flex issues!
 
quote:

Originally posted by JohnBrowning:
No, It is not that great of an engine. It's only real advantage is weight! THey used this engine in the SSR and the Trailblazer because the front end could not take the weight of other V8's that theyb have. They also do not have the capacity and are not willing to but higher output engines in these vechile. They would have to redsesign the front structure, transmissions etc....... to use other V8's.

Just look at the SSR's lack luster performance numbers!!

Rest assured that they are going to have to limit the how much power you can apply from a dead stop to keep torque steer in check. They are also going to have some handleing issues. What they really need to do is build these vechiles as rear wheel drives that why engine comprimises are not being made due to transmission and structure limitations!

Truthfuly the high content 3.9 wich is a bigger version of the high content 3.6 would be ideal for both of these vechiles in their current drive configuration. They are not building the 3.9 yet.Even the 3.6 would be good choice. I am sure that they are probably not able to produce enough 3.6's yet to meet their current demands though.

They know that they can not improve fit,finish, materials, handleing,durability etc.... cheaply or quickly! So instead of redesigning yet again to catch up with the industry they are trying to move in a different direction to try to minimize their weak areas. It is easy and cheap for them to shoe horn a larger engine in place. I am sure that they have more production capability then they need for the LS4.

I suspect that the power output has been kept low on this engine due to flex issues!


LOL, doesn't sound at all like you have an axe to grind with GM. like the rest of the LS family, the 5.3 is one of the best V8 engines on the market (certainly at least as good as competing domestic V8 families). I don't have the weight figures but I would be VERY surprised if the high feature V6 or any other large OHC V6 is appreciably lighter. Powertrain is one of the areas in which GM is an industry leader. GM quality is on par with or better than the other domestic manufacturers, and many of the imports. I assure you, chassis flex was not a problem with the grand prix platform, have you seen the engine cradle? your opinion about the small truck chassis being unable to support larger engines is also incorrect. of course there are obviously advantages to fitting the lighter aluminum engine in vehicles. also, the SSR was fast for a truck with the 5.3, and very fast now with the 6.0.
 
The SSR is a pig, and that is why performance suffers. 300HP can only do so much with 5000 pounds. The gxp will have front wheels and tires that are wider than the rears, to compensate for the additional power. The 5.3 will be lighter than the SC 3.8 that is currently used. 290HP should make it a fun car to drive. But I do have to agree with JB that GM should have just designed a proper RWD platform for the GP.
frown.gif
 
It's 303 HP (not 290).

A GXP (LS4) is essentially the same weight as a Comp G (L67). (actually 17 lbs heavier according to GM).

P.S. Some of us still like FWD since you have a fighting chance to get around in an ice or snowstorm.

quote:

Originally posted by sbc350gearhead:
The SSR is a pig, and that is why performance suffers. 300HP can only do so much with 5000 pounds. The gxp will have front wheels and tires that are wider than the rears, to compensate for the additional power. The 5.3 will be lighter than the SC 3.8 that is currently used. 290HP should make it a fun car to drive. But I do have to agree with JB that GM should have just designed a proper RWD platform for the GP.
frown.gif


 
Found it. Busted and corrected...
wink.gif
. Where is the 303 hp figure coming from? The Pontiac website claims only 290 hp.

This whole Pontiac thing has me confused. If they were going to the trouble of dropping a new 300-ish hp aluminum V-8 into the GP, why is the Northstar, at only 275 hp, newly residing under the Bonneville's hood??? If I just spent over $35k for a V-8 B-ville, I'm not going to be too happy to find that I could have gotten a more powerful V-8 GP for a good bit less. Who's got the muddy thinking problem, me or the Pontiac strategists???
 
The figure comes from the same engine in the Chevrolet application:

"New 5.3L Small Block V8 Engine
The legendary small block V8 returns in Monte Carlo SS. This V8 features electronic throttle control and new Displacement on Demand (DOD) technology that seamlessly deactivates four cylinders when V8 power is not needed-such as cruising on level roads-for greater fuel economy.(1) The 5.3L small block V8 delivers 303 hp and 323 lb.-ft. of torque."

http://www.chevrolet.com/montecarlo06/

As far as the 275hp Northstar, the owners of the Bonneville GXPs can brag about the "technology" they paid for as opposed to the extra horsepower in the LS1 based Grand Prixs.
 
Got boost GM actualy said that the front suspension was the reason for the LS4 in the Trailblazer! So I guess GM is lying to their own employees on the internal Socrates Intranet! I was quteing GM and the reason they gave.

As to flex I was talking about block flex with reguard to the engine! THe LS4 is horable under powered for it's displacement.

I do not have an axe to grind with GM at all. I worked for them as a contractor through a contract house and have no bad feeling for GM at all. I do think they are incompetent though due to internal politics, gross mis-mangement and bean counters!

GM is not a leader in powertrains at all. The best engine they have come from other companys. They have the some of the worst transmissions on the market in terms of long term durability. Their engines are plagued by knock,slap,oil consuption,oil leaks, high copper,tin and lead levels etc..They have a lot of problems with everything ie wiper modules, headlamp actuators, relays, power distribution buses, injectors, fule pumps, fuel rails, every gasket on the engine, intake manifolds,brake modulation valves, electronic brake control modules/traction control,multi-funtion switch, all of their lines it does not mater if they are fuel lines,break line or oil lines, rear ac lines on Astro's, climate control, delayed blower control modules, blower motors on Cadilacs, weather striping esp. on Convetes with removable tops or convertables, hinges and doors on center consoles, hubs on all cars and trucks, break rotors etc........ These are just some of the common failure items that most owners can expect to replace slightly out of warranty! It is a mighty long list!!!

You forgett I worked in quality for GM and they were not paying me so I have no loyality to them at all. I can tell it like I saw it and reported it. I was the one that first broke the oil line issue on products equiped with a 4.3V6's. I can remeber the 65,000 back orders for these lines while engineering was trying to desigg a fix. When I broke this ongoing issue to GM's Executive Staff it had been an isues for two years and no one in their Quality department had a clue it was a problem! Even with 65,000 back orders they still had no clue. They were even warranting engines that were under warranty and still did not have a clue.

You would have to be grossly out of touch with the market to accept knocking,slapping,oil consuption and all of the other problems as normal for a modern engine!

P.S. I have not worked for Ford or DC and my previous experince is with Toyota and European makes. IF someone asked me my take on French cars it would not be a preety picture either! I am even critical of Toyota at times. I try not to be too biased but I can only base my findings on what I have seen and what I can compare it too. All ofmy information is first hand 90% of the time.

[ January 16, 2005, 05:35 PM: Message edited by: JohnBrowning ]
 
Hmmmm. The ls4 has more HP per liter than last years 4.6 liter DOHC toyota engine...........and I recall someone defending the power output of that engine.............and the 5.3 still gets as good if not better fuel economy than toyota's 4.6.
 
quote:

Originally posted by JohnBrowning:
Got boost GM actualy said that the front suspension was the reason for the LS4 in the Trailblazer! So I guess GM is lying to their own employees on the internal Socrates Intranet! I was quteing GM and the reason they gave.

As to flex I was talking about block flex with reguard to the engine! THe LS4 is horable under powered for it's displacement.

I do not have an axe to grind with GM at all. I worked for them as a contractor through a contract house and have no bad feeling for GM at all. I do think they are incompetent though due to internal politics, gross mis-mangement and bean counters!

GM is not a leader in powertrains at all. The best engine they have come from other companys. They have the some of the worst transmissions on the market in terms of long term durability. Their engines are plagued by knock,slap,oil consuption,oil leaks, high copper,tin and lead levels etc..They have a lot of problems with everything ie wiper modules, headlamp actuators, relays, power distribution buses, injectors, fule pumps, fuel rails, every gasket on the engine, intake manifolds,brake modulation valves, electronic brake control modules/traction control,multi-funtion switch, all of their lines it does not mater if they are fuel lines,break line or oil lines, rear ac lines on Astro's, climate control, delayed blower control modules, blower motors on Cadilacs, weather striping esp. on Convetes with removable tops or convertables, hinges and doors on center consoles, hubs on all cars and trucks, break rotors etc........ These are just some of the common failure items that most owners can expect to replace slightly out of warranty! It is a mighty long list!!!

You forgett I worked in quality for GM and they were not paying me so I have no loyality to them at all. I can tell it like I saw it and reported it. I was the one that first broke the oil line issue on products equiped with a 4.3V6's. I can remeber the 65,000 back orders for these lines while engineering was trying to desigg a fix. When I broke this ongoing issue to GM's Executive Staff it had been an isues for two years and no one in their Quality department had a clue it was a problem! Even with 65,000 back orders they still had no clue. They were even warranting engines that were under warranty and still did not have a clue.

You would have to be grossly out of touch with the market to accept knocking,slapping,oil consuption and all of the other problems as normal for a modern engine!

P.S. I have not worked for Ford or DC and my previous experince is with Toyota and European makes. IF someone asked me my take on French cars it would not be a preety picture either! I am even critical of Toyota at times. I try not to be too biased but I can only base my findings on what I have seen and what I can compare it too. All ofmy information is first hand 90% of the time.


DARN! I guess my '93 Cavalier with 220k plus miles, and my battleship '96 Caprice with 175k plus miles are just going to lay down and die any decade now.
 
In my experience anything V8 that Chevy has made has been a very tough engine indeed. I've raced Chevy V8's from 283 CI on up with winning results. I've had at least one Chevy V8 powered automible of one form or another in my driveway for the last 25 years. Several of these were raced on weekends and then driven to work on the following Monday. I have never been disappointed with their performance or longevity. Rickey.
 
I think GM's biggest problems are the peripherals! In other words, their engines are good to very good and so are their transmissions. It's all the little crap that keeps you from buying another GM. My Z28 hasn't had any engine related problems. It did slap and GM replaced the pistons. Oil analysis before and after showed the engine was wearing better than average.
Now, if you talk to me about fit/finish, brake rotors materials, sounds/noises, paint, and overall driving feel......I agree 100% with JB.

JB, I do think you have something against GM....most of it rightly so, but some of it is ridiculous! You are the one who said the tailgate on the Avalanches were rusting through......when they are made of plastic composites.
 
The LS4 is not the same engine used in the SSR or Trailblazers. It's a GEN IV engine, which should make it even better then previuc LS engines. The GEN III engine have proven to be very reliable and have good efficiecy. The piston slap was never a real big issue and oil consumtion issues were mainly from hard driving. For those worried GM now uses full floating wrist pins and they have redesigned the PVC system.

-T
 
quote:

Originally posted by JohnBrowning:
Truthfuly the high content 3.9 wich is a bigger version of the high content 3.6 would be ideal for both of these vechiles in their current drive configuration. They are not building the 3.9 yet.Even the 3.6 would be good choice. I am sure that they are probably not able to produce enough 3.6's yet to meet their current demands though.

The 3.9 is a 3900 and despite having features like DoD, I believe it's a pushrod engine, thereby having nothing in common with the high feature 3.6L. I just can't remember if it's a 60* V or 90*. 60* would relate it to the new 3500 and 90* would make it a successor to the 3800.
 
quote:

Originally posted by JohnBrowning:
THe LS4 is horable under powered for it's displacement.

Yeah but how's the weight? Good. How's it drive? Good. Mileage? Good. What's it cost? Less than the Northstar in the Bonny (with more HP and torque). What's your problem again?
 
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