Questions and Answers

Jolting Question Q. I have a 1999 Chevrolet Astro Van 4.3 liter V-6 4 speed automatic with 98,500 miles on it. A few hundred miles ago it started having a jolt or a hard miss (without any engine lights going on) intermittently and then more often. My husband changed the plugs and wires, which seemed to ease the problem for a few days but then it came back.

We are the proud owners of a 100,000 mile warranty, however, after spending $200 for diagnostics at two different dealers (GMC and Chevrolet) they all say they know there is a problem but none of their diagnostics show what it is. The Chevy dealer used an oscilloscope and says that when the car jolts nothing shows up on anything.

The Chevy guy says he thinks it is the engine or the transmission, but without spending $1,000's for diagnostics (not covered by the warranty of course) he doesn't know what repair may be necessary and if it is a repair covered by the warranty. The hard misses are intermittent, but sometimes they are closely spaced. The van does not backfire. Any suggestions would be appreciated more than you can imagine, since we still owe quite a bit on this white elephant.

Linda

A. I would think that the injectors are the culprit here. They are prone to deposit buildups and start to stick open or closed. GM has a new cleaning procedure which, if I'm right, will correct the problem. Have the dealer refer to TSB Number: 00-06-04-003 and perform the injector cleaning.

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