Misfire or TC Shudder?
Thread Starter
|
Junior Member
Joined: May 2009
Posts: 2
Likes: 0
Misfire or TC Shudder?
I have a 97 F-150 that I picked up as my run-around truck. It had 189K when I got it and needed a little work. As I've worked the kinks out, one of the more recent ones I've noticed is what I think to be torque converter shudder, but not in the typical Ford sense as in other posts in the forum.
Mine is only above 55 mph, in OD, when I let off the gas. The rpm hangs up for a few seconds, it gets a shudder much like a mild rumble strip, then when the rpm releases, it's smooth and the rpm winds down normally. It really doesn't happen in other gears and slower speeds. Normal starting, acceleration, and shifting are all fine & dandy.
As part of my "little work" to get it up to speed, I've replaced the rear end fluid (w/ friction mod), replaced the u-joints, had the drive shaft balanced, and replaced the motor mounts and transmission mount. I've also replaced the tranny filter & gasket, and then did a full flush and added a can of BG.
The shudder is still there. My thought is it's the TC just being slow to release, and unless I want to replace it, drive it until it goes completely.
The only other thing I can think of from other posts is a low grade misfire. I have an OBDII code reader, and it shows clean, no codes. The plugs in it when I got it were Bosch Platnium Plus, and they look pretty good. The plug wires have been replaced at somepoint because they're from Carquest. The coil packs appear to be stock, because they're Motorcraft. They're at least not aftermarket.
I've spent a few bucks thus far chasing this vibration, and I'm hesitant to throw more at the ignition system if it's still just the TC slow to release.
How long are stock coil packs good for? Just TC shudder from being slow to release, or a low grade misfire?
Mine is only above 55 mph, in OD, when I let off the gas. The rpm hangs up for a few seconds, it gets a shudder much like a mild rumble strip, then when the rpm releases, it's smooth and the rpm winds down normally. It really doesn't happen in other gears and slower speeds. Normal starting, acceleration, and shifting are all fine & dandy.
As part of my "little work" to get it up to speed, I've replaced the rear end fluid (w/ friction mod), replaced the u-joints, had the drive shaft balanced, and replaced the motor mounts and transmission mount. I've also replaced the tranny filter & gasket, and then did a full flush and added a can of BG.
The shudder is still there. My thought is it's the TC just being slow to release, and unless I want to replace it, drive it until it goes completely.
The only other thing I can think of from other posts is a low grade misfire. I have an OBDII code reader, and it shows clean, no codes. The plugs in it when I got it were Bosch Platnium Plus, and they look pretty good. The plug wires have been replaced at somepoint because they're from Carquest. The coil packs appear to be stock, because they're Motorcraft. They're at least not aftermarket.
I've spent a few bucks thus far chasing this vibration, and I'm hesitant to throw more at the ignition system if it's still just the TC slow to release.
How long are stock coil packs good for? Just TC shudder from being slow to release, or a low grade misfire?
Thread Starter
|
Junior Member
Joined: May 2009
Posts: 2
Likes: 0
No, it's not individual coils for each plug. There are two coil packs, with 4 leads each. One mounts on the left, and one the right, each forward of the block. Each pack has traditional wires running from it to the plugs. Each pack sends two wires to it's side, two to the other. Motorcraft part# DG457.
