Car sporadically skips when accelerating; no warning lights & no alerts on 3 mechanic diagnostics

I have a 2003 Buick LeSabre with 187,000 miles (mostly highway) that skips/jerks sometimes when accelerating, even when in cruise control. It only does this every month or so; and, of course, never does it when the mechanic is in the car. No warning lights have ever appeared and my mechanic says no codes have shown up in three diagnostic tests. In the last 1.5 years, the following items have been replaced: power steering rack, oil pressure sensor, FE control arm bushing, intake manifold gasket, oil pan gasket, transmission mount, water pump, rear struts. In 2010, an alternator, thermostat, mass air flow sensor and front brake pads were installed. Oil is changed as scheduled; tires are rotated as required and car is serviced at the first sign of any problem. Other than occasional skipping, car is in pristine condition and rides like a charm.

The most recent skipping occurred March 29th when I was 200 miles from home. It lasted sporadically for about 10 miles and did not occur in the other 190 miles.

Sounds tome like your transmission may be "hunting. I would have it checked next.

Of all the items mentioned, I noticed the fuel filter was not included. The fuel delivery system is not monitored by ODB-II, except for fuel injevtor feedback. A skip in the engine could be due to fuel pressure irregularities caused by a partially clogged filter. At 187,000 miles, it certainly could not hurt.

It’s worth a shot, why not? There’s no code for a filter being half stopped up. Even I would try fixing it by changing the fuel filter. Somebody would make a little money from me for a change.

I too am inclined based on the symptoms and the age of the vehicle to consider the fuel delivery to be a good possibility. However, I’d suspect the pump itself.

Does anybody know if this car has a replacable fuel filter???


If the fuel pump has never been replaced and the filter has not been changed regularly then my guess would be a pump going intermittent; which is not a rare thing to happen.

Other possibilities could be an intermittent engine miss, vacuum fault all depending, or something like a poor connection at a battery junction terminal.

Mechanics will sometimes route a fuel pressure meter right into the passenger compartment and drive the car while watching the fuel pressure. That would be reasonable to do in this case I think. My first suspicion though is something isn’t quite right in the ignition system. Have all the ignition components received the recommended routine servicing? At the minimum, the HV wires should be carefully checked for any cracks in the insulation. Assuming the CEL is not on. Even so, pending codes are possible, and they should be read and posted here.