engine differences between 2001 and 2002 [Archive] - GrandAmGT.com Forum


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06-30-2004, 07:24 AM
anyone aware of any engine differences btw the 2001 and 2002 gt1's? I have one of each, 2001 is a speed deamon, 2002 is very slow, feels like i'm driving a V4 (its a v6) when stepping on the gas peddle. gm REFUSES to give me a straight answer. I need help to correct this!

06-30-2004, 07:28 AM
theres an engine problem somewhere. the engines should be almost identical.

edit: unless maybe the battery was disconnected recently on the slower GT... that would cause it to run a little weird and maybe not as fast/responsive for a short time.

06-30-2004, 07:29 AM
As far as I know, there are zero differences between the two engines. Have you tried trouble-shooting any problems with the '02?

By the way - welcome to the boards... The east coast has the most fun!

06-30-2004, 07:45 AM
By the way - welcome to the boards... The east coast has the most fun!

haha oh geez, the dogs are out already!!

welcome, and it seems a little shady that GM refuses to give you any answer.....

06-30-2004, 07:59 AM
sounds like a problem.....have someone other than GM run it for codes..

What up Jersey

06-30-2004, 08:07 AM
I think the only difference form '01 to '02 was PCM programming but that should not affect performance at all. It was done mostly for emmisions improvements.

Sounds like an "oddball" engine ... either a "dog" new one or "hot " old one ...

06-30-2004, 09:53 AM
Application in Buick Rendezvous
Application with All-Wheel-Drive in the Long-Wheelbase Chevrolet Venture, Pontiac Montana and Oldsmobile Silhouette.
Improved Cruise Control
Improved Spark Plug Wires
Shield For Air Injection Reaction (AIR) Solenoid
Revised Transaxle Brace
Revised Takedown Pipe for Minivans

The 3.4L LA1 will power the 2002 Rendezvous, Buick's all-new compact sport-utility vehicle. For the Rendezvous, the 3.4L LA1 will be trimmed with hardware identical to LA1s installed in the Pontiac Aztek. A model-specific oil pan and additional braces for the all-wheel-drive system distinguish the Aztek/Rendezvous variant The oil pan has special bosses to accommodate a brace for the AWD power drive unit, and a revised transmission bracket adds a "pencil brace" to secure the power drive unit. Finally, the Powertrain Control Module (PCM) software adds calibration values to monitor sensors and manage the AWD system.

The 3.4L LA1 will also power new all-wheel-drive versions of the long-wheelbase Venture, Montana and Silhouette. LA1s for AWD minivans are nearly identical to those installed in the Aztek and Rendezvous. They have an additional structural brace for the AWD transaxle.

The cruise-control module for all 3.4L LA1s has been updated with state-of-the-art electronic circuitry. A new control algorithm learns the driver's commands more quickly and updates itself every 30 seconds. This cruise module, supplied by Delphi and mounted on a bracket inside the engine bay, allows GM Powertrain engineers to calibrate cruise control more specifically to specific vehicles, including those with all-wheel-drive. The customer will notice more precise speed settings and faster, smoother adjustments.

The cruise module is coupled with a servo that eliminates the need for cable adjustment, and a cable adjuster is no longer required with the 3.4L LA1. The cruise module requires a unique bracket for installation in Chevrolet Impala and Monte Carlo.

All 3.4L LA1s get new "high tear," low capacitance plug wires. The wires are assembled and installed as a harness, improving production efficiency, and are so resistant to damage that they no longer require a protective conduit. Further, with 5000 ohms resistance, the new wires reduce the likelihood of electromagnetic interference with AM band reception.

The solenoid that controls AIR (an emissions control system that injects warm, fresh air into the combustion process) on the 3.4 L LA1 is now protected by a metal shield. The solenoid and shield mount on a bracket on the engine. The shield protects the solenoid and AIR vent from liquid and particle contamination, improving reliability and extending durability.

All 3.4L LA1s have a slightly revised brace between the transaxle and engine block. The brace was altered at the request of the Doraville minivan plant to improve assembly efficiency.

The downpipe connecting the exhaust manifolds with the catalytic converter has been revised for LA1s installed in minivans. The "air gap" pipe works exactly as before. It has dual walls separated by a jacket of air, and heats more quickly than conventional single-wall steel pipe, helping the catalytic converter heat more quickly and speeding emissions light-off by as much as five seconds. The pipe was revised to accommodate the all-wheel-drive system in long-wheelbase minivans.


The 3400 V6 was developed for the 1996 Chevy Venture, Olds Silhouette and Pontiac Montana. The engine block is similar to the 60-degree 3.1L LG8 V6, but requires a unique casting to increase the cylinder bore three millimeters, in turn increasing overall displacement 200 cc. The LA1 was first used in a passenger car in the 1999 Pontiac Grand Am, and its application has expanded steadily since.

The 3.4L LA was significantly revised for model year 2001 in preparation for use in the Pontiac Aztek, and exhaust emissions were a key target. Improved technology increased the catalytic converter's efficiency, allowing national Low Emissions Vehicle (NLEV) certification with considerably less catalyst volume and lower cost. Improved production methods allow a thin-wall catalyst substrate and new catalytic coating application. These techniques mean equal or improved performance with less platinum, palladium and other precious metals in the catalyst. The air gap downpipe spread to all applications. On Vehicle Vapor Recovery (OVVR), which keeps gasoline vapor from escaping into the atmosphere, was also extended to all cars and trucks powered by the 3.4L LA1.

Improved durability was the second major objective in 2001. The seal around the water pump shaft was converted to a more durable hard carbon on silicon carbide. Bearings in the accessory belt tensioner and idler, which maintain proper belt tension without adjustment, were validated to 150,000 miles of service. The bearing seal was improved to keep the lubricant in and water, dirt and other contaminants out.

For improved driving satisfaction, a new throttle body spring lightened accelerator pedal feel in all cars equipped with LA1s. A hole in the throttle blade has been eliminated, reducing the minimum airflow rate and lowering engine idle speed.

Revisions for model year 2000 enhanced both performance and durability. The cylinder heads and oil pan were fitted with new, leak-resistant gaskets. Multec II fuel injectors improved fuel efficiency by making fuel delivery more precise, and reduced the likelihood of injector clogging. Fuel pressure was increased from 300 to 380 kpa for improved hot starting. A number of enhancements reduced internal engine friction, in turn reducing noise and improving fuel economy. Those included reduced friction piston rings, revised cam profiles and a new cam gear and drive chain.

The 3.4L LA1's success proves that refined overhead valve technology, meets customer needs for good specific output, a broad torque band, economy and durability at reasonable cost to both the corporation and the customer.

"The 3400 is a world leader in large car and minivan applications. It delivers great fuel economy and competitive output to go with it. That's why it's in high demand with the platform teams."

**Mark VanderEyk, Assistant Chief Engineer, 60-degree and 90-degree V6

06-30-2004, 12:46 PM
haha oh geez, the dogs are out already!!
Get a life - I don't e-pimp