Had Truck Tuned Up... I am Amazed

[Iplayfarmer]

I took my '99 Chevy Silverado 1500 in to my mechanic last week. They did about $900 worth of work including tie rods, CV seals, alignment, Tranny Flush, and tune-up (including new plugs and wires).

I have typically gotten about 15 mpg in this truck, 16 on a good tank in the summer if I drive very conservatively. After the Tune-up, I used the truck to haul some stuff down to relatives in Salt Lake City. I checked my milage going down and then again coming back, and I was amazed. I got over 15 MPG on the way down. That was loaded, in 4wd some of the way, and it included about 30 minutes of sitting stopped in traffic waiting for an emergency crew to mop up a wreck.

On the way back I got 17.7 mpg! I was in 4wd most of the way, and there's some up and down through mountains too. I've never seen gas mileage this good in this truck.

 

[bx23barry]

maybe they reset the speedo I did have a '89 chev that got 20mpg down the highway so 17 in 4wd may be possible.

 

[jwstewar]

Quick question. What brand of spark plug wires did you use? I put a set of my '99 Silverado Dec. '07 (don't remember the brand), but relatively cheap (+/- $50) from Autozone. Drove the truck about 3,000 miles and started having "Transmission" problems. The truck would buck, wouldn't shift, just all kinds of problems. I started looking for transmissions for it. Then all of a sudden I got a check engine light. Random misfires. Replaced the wires last August with a set of factory AC/Delco and all is fine. Saving $50 cost me a lot of aggravation and the loss of the truck as we were afraid to drive it too much until we replaced the transmission. On some of the forums I've been on, I've heard a lot of problems with different wires other than ACs. Not sure what they are doing, but it sure is strange.

 

[Iplayfarmer]

Quick question. What brand of spark plug wires did you use? I put a set of my '99 Silverado Dec. '07 (don't remember the brand), but relatively cheap (+/- $50) from Autozone. Drove the truck about 3,000 miles and started having "Transmission" problems. The truck would buck, wouldn't shift, just all kinds of problems. I started looking for transmissions for it. Then all of a sudden I got a check engine light. Random misfires. Replaced the wires last August with a set of factory AC/Delco and all is fine. Saving $50 cost me a lot of aggravation and the loss of the truck as we were afraid to drive it too much until we replaced the transmission. On some of the forums I've been on, I've heard a lot of problems with different wires other than ACs. Not sure what they are doing, but it sure is strange.

I never did ask what brand of wires they used. Knowing this guy, though, they were either OEM stock replacement or something good. That's why I like this guy. He doesn't try to cut corners.

 

[WilliamBos]

I took my '99 Chevy Silverado 1500 in to my mechanic last week. They did about $900 worth of work including tie rods, CV seals, alignment, Tranny Flush, and tune-up (including new plugs and wires).

I have typically gotten about 15 mpg in this truck, 16 on a good tank in the summer if I drive very conservatively. After the Tune-up, I used the truck to haul some stuff down to relatives in Salt Lake City. I checked my milage going down and then again coming back, and I was amazed. I got over 15 MPG on the way down. That was loaded, in 4wd some of the way, and it included about 30 minutes of sitting stopped in traffic waiting for an emergency crew to mop up a wreck.

On the way back I got 17.7 mpg! I was in 4wd most of the way, and there's some up and down through mountains too. I've never seen gas mileage this good in this truck.

Which version are we talking about? The classic, or newer?? 5.7L or 5.3L?? I assume he used AC Delco plugs and wires. We did a tune up on ours just after Christmas, man what a difference.

 

[Iplayfarmer]

Which version are we talking about? The classic, or newer?? 5.7L or 5.3L?? I assume he used AC Delco plugs and wires. We did a tune up on ours just after Christmas, man what a difference.

5.3L.

I love that engine. It seems to have at least as much torque as the old 350, but it's lighter and more efficient.

 

[WilliamBos]

5.3L.

I love that engine. It seems to have at least as much torque as the old 350, but it's lighter and more efficient.

I second that!! I love the 5.3L also, you could not get me back in a 350 powered vehicle EVER again.

 

[DieselPower]

Quick question. What brand of spark plug wires did you use? I put a set of my '99 Silverado Dec. '07 (don't remember the brand), but relatively cheap (+/- $50) from Autozone. Drove the truck about 3,000 miles and started having "Transmission" problems. The truck would buck, wouldn't shift, just all kinds of problems. I started looking for transmissions for it. Then all of a sudden I got a check engine light. Random misfires. Replaced the wires last August with a set of factory AC/Delco and all is fine. Saving $50 cost me a lot of aggravation and the loss of the truck as we were afraid to drive it too much until we replaced the transmission. On some of the forums I've been on, I've heard a lot of problems with different wires other than ACs. Not sure what they are doing, but it sure is strange.

You didn't have the plug wires misrouted by chance did you? I don't mean hooked to the wrong plug but routed wrong. On some engines if you cross certain plug wires you can get misfires between two cylinders. Have seen this more than once in my years working in service shops.

 

[jwstewar]

You didn't have the plug wires misrouted by chance did you? I don't mean hooked to the wrong plug but routed wrong. On some engines if you cross certain plug wires you can get misfires between two cylinders. Have seen this more than once in my years working in service shops.

Nope, it is a coil near plug design. The plug wires are only about 6" long. They are barely long enough to stretch out far enough to get the boot over the end of the plug. I'm so glad it was a simple fix, but yet so mad at myself for trying to save a buck and caused me so much grief.