Back in April, I posted this comment about occasional skipping when accelerating: “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.”
Based on the advice of responders, I had the fuel filter replaced and the car never skipped again … until today, three days after the rotors and brakes were replaced. Like before, there have been no warning lights and the skip, which can occur when braking or when in motion, occurs sporadically. It might happen several times in a mile and then not happen again for some time. The car now has 192,000 miles. Is this the transmission, a problem with the recent brake installation or something else?
I would be suspect of the crank sensor, especially if its a 3800. I had a slight miss under load with my 3800 and tried pretty much everything. The shop I took it to didn’t find anything until it broke and they showed me the failed crank sensor. It had been replaced once before that also with oil contaminating it.
I don’t understand the comment about the oil contaminating the crank sensor. On the day the brakes and rotors were replaced, I also had the oil changed and the tires rotated. Could any of those services have disturbed something else (e.g., oil contamination, the fuel filter, etc.) to create the skip? Since the car never skips when I take it to the mechanic, what can I expect if it is the crank sensor and it breaks (i.e., will the car just die on me)? Is it dangerous to drive in the interim? Should the mechanic be able to diagnose a broken/damaged crank sensor issue if I specifically ask for it to be checked? What can I expect replacement to cost?
Same questions for the “input turbine speed sensor” (whatever that is) comment. What can I expect if it is the input turbine speed sensor and it breaks (i.e., will the car just die on me)? Is it dangerous to drive in the interim? Should the mechanic be able to diagnose a broken/damaged input turbine speed sensor if I specifically ask for it to be checked? What can I expect replacement to cost?
The basic issue I guess is what you mean by “skip” and if its the transmission or the engine. If you mean a miss, then the engine. If you mean a momentary jerk or slip, then transmission. Probably just going to have to have someone drive it to try and figure out which. Don’t know anything about the turbine.
The first crank sensor I had replaced had oil seeping into the connectors I believe. I was just told it was a common problem. Its unlikely any of the services performed had anything to do with it. If the crank sensor goes out, the engine will just die. Sometimes the harmonic balancer on the end of the crankshaft will deteriorate and start to wobble and cause a problem with the crank sensor also. (Don’t know if the 03 still has the sensor mounted over the balancer or not.) That;s the extent of my knowledge on the subject.
I’m having what I think is a similar issue, sometimes more serious. My 2000 will stumble for a second, has actually stalled a couple times. It’ll start right back up then. Other times (this was happening once a week, then ‘fixed’ itself and hasn’t done it much for a few months) the car will not restart when hot, after a short stop. I get back in and crank it over, but no sign of any firing. If I let it sit about twenty minutes, it’ll start right up. There is some evidence of a slight oil leak on the right side of the engine. I’ll keep that crank sensor in mind, but the symptoms sound a little different than what Bing had. It’s the 3800. I think I read somewhere that there is also some kind of safety fuel shutoff switch, which could make sense on mine since I get no firing at all when the no-start happens…