Engine Split Second Hesitation In 4.6l 98 Gt

[Stub32]

I have a 98 gt 4.6l. I have a momentary tick, hick up at any speed, What ever you want to call it.. There are no codes. Took it to a shop and he found no codes in the computer. He put it on all his testing equipment and found nothing. There is no pattern as to when it happens. It seems to maybe have started after an oil change at one of those oil changers shop, but not real sure. However we discovered that I was down a qt. of oil.I think they shorted me. The engineer is in really great shape. It has a factory rebuilt engineer with about 40k on it,. The smog check showed it was running like a new car. I don't drive it alot, only weekends.. Mechanic replaced a couple small sensors that had to do with sending information from the crank to the computer. We where just guessing at that point. It is just a split second hesitation. Does anyone have this problem? Any ideas would be appreciated.

 

[mogs01gt]

It is an auto?

 

[Stub32]

It is an auto?

Yes auto tranny.

 

[Stub32]

Yes auto tranny.

Yes auto tranny

 

[mogs01gt]

Yes auto tranny.

It's your tranny.

 

[Stub32]

Can you explain? When it hesitates the Rams drop and come right back

 

[flstang65]

Coil pack or 2 would be my guess.

 

[Stub32]

Coil pack or 2 would be my guess.

Was wondering why you guessed that. I looked at them and one had cracks at the screw holes. They are Ford motor craft. They could be the originals. The car has had 230,000 miles on it. The engine has 40,000 on it. One last thing is that when it does it the RPM's drop and then come right back.

 

[flstang65]

If you have a miss, then it can feel like a stutter or hesitation. The check engine light doesn't even have to be on.

 

[Stub32]

If you have a miss, then it can feel like a stutter or hesitation. The check engine light doesn't even have to be on.

I change the coils and it still hesitates. Any other ideas? If I take it to the Ford dealer do think they can diagnose it. Do they have the equipment to figure it out?

 

[flstang65]

Did you check the plugs and wires?

 

[Stub32]

Did you check the plugs and wires?

Ok Coils ,spark plugs and wires (all motorcraft), crank sensors changed, all ground points checked and throttle body sensor changed. Still does it . Any other ideas?

 

[Stub32]

Ok Coils ,spark plugs and wires (all motorcraft), crank sensors changed, all ground points checked and throttle body sensor changed. Still does it . Any other ideas?

Also, has new fuel pump and filter. Only 3/k miles on these

 

[flstang65]

I would need my scan tool at this point

 

[Stub32]

I would need my scan tool at this point

Took it to an exclusive ford Mechanic with very good credentials and they put it thru the paces with a Ford scanner and it shows nothing. It did it during the scan and nothing. He suggested the cats may be the problem as they crackel when cold. It passed a smog test a year ago with flying colors. Still at a loss. Could the computer be having problems?

 

[flstang65]

Auto or 5 spd?

 

[Stub32]

Auto or 5 spd?

Auto

 

[Max22]

When did you change your front o2s last? That could give it a little studder if one is going out, although that should throw a code...

 

[Stub32]

About a year ago I don't drive that much as it is a casual. Car. It seems to happen at speeds below 50. I'm wondering if it might be some type of air flow problem. It's something that won't code

 

[Stub32]

Three good mechanics no one knows. If the computers don't show a code and the problem being sporadic no one knows how to repair