Faults:
1. Fuel economy is terrible. 5.3 L VorTech V8 was a trade-off between economy and power. Did not realize that I would get the bad deal of both, I.E.: No power and very poor fuel economy (approx 14 Highway mpg). Numerous complaints to dealers went nowhere. Absolutely no torque or power unless engine rpm is at 2000. Seems like it takes forever to merge into highway traffic. Evidently engine computer retards timing and throttle to 140 foot pounds of torque until 2000 rpm. GM explanation for doing this is to keep engine damage down since this is when most engine damage occurs at full throttle take offs. By comparison, neighbor with same truck, but with larger 6.1L motor gets better fuel mileage and also has the power. My 95 Ford F150 Ext Cab 1/2 T truck with 5.8 L V8 gets 18 mpg hwy and has the power.
2. Transmission: The transmission can't figure out what to do when I'm going up relatively minor grades and trying to keep a constant speed between 30 and 50 mph. The whole truck stutters as the transmission seems to keep changing gears with the corresponding jumping up and down of eng rpm. I cannot use O.D. because the constant shifting up and down is even worst. Dealer says normal operation. Transmission will also shift into OD when engine is cold at 30 mph The early wearout of the transmission clutches will of course be at my expen$e.
3. Seats: No storage of anything possible under front seats (even road maps). You also cannot put anything onto center seat without it sliding off onto the rear floor through the seat. No storage cubbyholes anywhere in the front console. Door pockets are not available to driver or passenger without opening door unless your arms are super-long. Center drink cupholders not removable. Unable to store folding umbrella under seat. Have to store under back seat which means that I have to stand in rain opening and closing doors. Unable to install standard dimension gunsafe under either front or rear seat. Seat fabric wears easily, fabric under child seats is quickly showing wear.
4. Headlights: Cannot shut off automatic headlights without having to repeatedly press an unlit button four times. A real pain in the butt when camping or to move car in driveway. Headlight glare reflecting off of garage door during rain makes seeing to back up safely a real challenge while fumbling for an unlit switch.
23rd Sep 2005, 22:30
Have the transmission flushed and serviced. My 2000 GMC did the same thing around 37,000mi. After servicing, the problem disappeared. I had no more transmission problems to 67,500mi when I traded the truck in. My 2002 GMC is slipping and moaning at 45,000mi. I plan to have it serviced soon. As for the engine sounds, it is common to hear a few rod knocks during initial start-up in very cold weather, any engine from any manufacturer can have this happen. Be sure your using SAE 5w30 weight oil. Your engine needs this oil due to tighter bearing clearances. If your rod knock persists, try a lighter oil in the cold weather, like 5w20, this will allow the oil to reach engine bearings faster in cold weather. The noises may also be piston slap. The LS1 engine has very finicky pistons. Because of the short piston height, they will exhibit piston slap at low engine speeds, 1000 to 1200rpm, especially in a cold engine. Because aluminum has a greater coefficient of thermal expansion then cast iron, GM gave the LS1 greater piston to cylinder wall clearance. This extra space allows the aluminum piston to expand as it warms up. Once at operating temperature, the clearance is decreased and piston slap diminishes.