[roadman1977]

I have a 2004 Mercury Sable with the DOHC. When you first start the car the idle goes slightly up and down (between 700 and 800 RPM). Once in a great while the car will sputter/miss ever so slightly when idling. As of a couple days ago when you are crusing (40 MPH and above) and push the gas pedal to accelerate you can feel the car miss and jerk. You only feel the miss/jerk if you push the gas pedal to gain a little speed...it does not miss if you have to hit passing gear (put the hammer down). The miss/jerk is really noticeable if you are going up a hill and push the gas pedal slightly to keep your speed. To put it in another perspective lets say you are doing 40MPH and you gradually accelerate to 45MPH...that is when you feel the missing/jerking. I opened the hood and listened to the engine run. I noticed when I jab the gas pedal you hear a rushing sound (kind of like air)...the car stumbles for a second then revs up. If I gradually give the engine more gas the engine does not stumble. It sounds like a vaccum leak but I am not sure. It sounds like the rushing noise is coming from under the upper intake manifold. Again this noise is only noticeable when you quickly push the gas pedal.

I have followed all maintanence on the car. The fuel filter is changed every year. The plugs are original but they are supposed to be good for 100,000 miles...my car has 91,600 miles.

Any advice is greatly appreciated.

 

[bull geek]

Check the coil on plug assemblies:

 

[sheila]

Check eng. light on? If so, get the code(s) read for free at autozone and report back.

 

[roadman1977]

No check engine light. The miss/sputter only seems to happen when the car is warm. Car does not sputter/miss when it has been sitting and the engine is cold. Although when you jab the gas the car hesitates for a second before reving. The check engine light is not on.

 

[Jeff K]

Use a scan tool that can show fuel trims and report back with the numbers.

 

[roadman1977]

The car did not sputter/miss at all today. I know the problem will probably re-appear at the most inconvenient time. Does this sound like a fuel problem? Can I rent a scan tool that does fuel trim? I was thinking it may be electrical but it can't hurt to check the fuel.

 

[sheila]

I would change plugs (theyre due), check coils for hairline cracks, general damage and inspect the pcv valve and its hose. Might look over all vacuum hoses, lines and their connections.

 

[northgatedad]

i've got an '03 duratec; reading cylinder 2 misfire; how hard is it to change plugs/wires?

sorry, i kept looking and found the spark plug thread.....

 

[Huggyb1972]

I have this same problem with my 00' Taurus DOHC. My problem is I don't know where #2 is. I changed spark plugs about 6k ago the old plugs had close to 60k on them and I never had the problem with them. This thing will do this one day and the next run just like normal I was useing NGK platniums before this time I went back with I think motorcraft or autolite platinums on the up side my hard start problem went away now it just runs terrible once in a while. 1st thing which cylinder is #2

 

[k8crd]

I have this same problem with my 00' Taurus DOHC. My problem is I don't know where #2 is. I changed spark plugs about 6k ago the old plugs had close to 60k on them and I never had the problem with them. This thing will do this one day and the next run just like normal I was useing NGK platniums before this time I went back with I think motorcraft or autolite platinums on the up side my hard start problem went away now it just runs terrible once in a while. 1st thing which cylinder is #2

With the hood up and standing at the front bumper,

going from left to right plugs are numbered 1,2,3 for the bank facing the firewall,

going from left to right plugs are numbered 4,5,6 for the bank facing the radiator.

 

[Huggyb1972]

I searched it and found it I just hope I can figure it out this is a pita it will run great for like two weeks then I leave it sit 3 or 4 days and it starts this crap and then it will run fine for who knows how long. I think it's jealous of the Bronco. Thanks k8crd

 

[roadman1977]

In my case the missing/sputtering problem seems to have been cause by a worn coil-on-plug boot. I changed the plugs, which did appear worn, but the problem did not go away. I later learned that you could replace the coil-on-plug boot without having to replace the whole COP unit. After taking off the UIM (again) I replaced the boots. I have driven the car in all conditions (including damp rainy conditions) and the problem seems to have been cured. Might want to replace plugs and COP boots and see if that works. My car sputtered/missed the most when it was damp out.