Shop can't find anything wrong with my car????

[nikkir86]

Well I've taken my car, A 95 Ford Contour, to get checked out. They said I needed a tune up, and that was all they could find wrong with my car. Anyway, my car has been jerking a lot at random, not everyday, and usually only after I've been driving and then parked for a short period of time. When I get back in the car, it will start jerking when I start driving. I usually pull over for a minute, and then continue driving and everything is fine. Although whenever I put the car in park, the O/D light comes on. I dont know what that means.  My car also takes a lot longer to pick up speed than it used to. I am still having this problem after the tune up. Its like a complete mystery to me. The mechanics said it was very hard to diagnose the problem since they weren't able to experience what I have been experiencing when I brought it in. What do I do?? This car has to last me the next 6 months before I am able to get a new one.

[br_tigerfan]

The mechanic is right.  If he doesn't experience it, it is hard to make a diagnosis.  Most shops are leery to suggest a repair when they aren't 100% sure what the problem is, because even though they can make an educated guess based on the symptoms you describe, it is still a guess, and they don't want an upset customer on their hands.

That being said, it doesn't sound like it would be too hard to duplicate the symptoms you are describing.  Drive it around for a while, park it in their parking lot, and let the mechanic start it up and drive it with a scanner hooked up to it.  You say the symptoms happen after the car has been parked for a short while.

The O/D light is for your overdrive.  If your regular mechanic can't help you, bring the car to a transmission shop and tell them the same things you wrote in your question.

[CountryBoy]

As a flier. I'd take a very close look at the EGR valve.



Also if you are trying to diagnose an ignition problem (jerking) as you drive it's really easy to solve. Open your hood and hook up an inductive timing light to #7 or #8 ignition wire. Newer timing lights require no battery hook up. If you can't find on of these find a hot wire under the dash and clamp the red wire to it. The black ground goes to any clean metal surface.



Tape the button on the timing light to the on position and set it next to you as you drive. When you feel comfortable hold the light in your right hand pointing upward. Don't look at the light directly. You'll notice the light may completely go out while the car goes into her jerking mode. You'll know instantly if you have an ignition problem.



If your car is a 95 it's time to pour a plastic can of 3M Total Fuel System Cleaner in your gas tank with no more than 14 gallons of gas. Plan on a hard high speed drive (trips). Don't re-fill your tank till it's near empty. This chemical cleans throttle bodies, fuel injection nozzles, intake manifolds, valves and combustion chambers.



If that doesn't fix the problem have a mechanic check the valve lift on every cylinder. You may have cam lobes wearing out.

[racefish68122]

I'd have to put my money on the torque converter clutch. GM had a lot of problems with these but not so much with Ford.