Driving Shudder?

June 27, 2006, 08:27:50 PM

I posted a time back about the feeling of a shudder. Thought it was the OD going in and out. Not so. Sort of a vacuum issue, I thought, since I was pulling a code #32. I can find no vacuum leaks, EGR works and holds vac, etc.
I finally have a description that suits what my car feels like - it's like I'm pulling a trailer. You know the feeling of push and pull that a trailer will give you? Well, that's subtly what my car feels like.
It runs great. Shifts great (a little harsh going into OD). Great power and accelleration. But that subtle little shudder is driving me nuts. Any ideas?

Driving Shudder?

Reply #1 – June 27, 2006, 10:37:30 PM

Couple shots in the dark...

Universal Joints in the driveshaft. Usually shutters when letting off the gas.

Improperly set/ loose TV cable. Don't know if that would cause a shutter though.

Driving Shudder?

Reply #2 – June 27, 2006, 10:44:37 PM

Silly thought.. check your tire pressure....

Driving Shudder?

Reply #3 – June 27, 2006, 10:47:08 PM

Quote from: sansabar

I posted a time back about the feeling of a shudder. Thought it was the OD going in and out. Not so. Sort of a vacuum issue, I thought, since I was pulling a code #32. I can find no vacuum leaks, EGR works and holds vac, etc.
I finally have a description that suits what my car feels like - it's like I'm pulling a trailer. You know the feeling of push and pull that a trailer will give you? Well, that's subtly what my car feels like.
It runs great. Shifts great (a little harsh going into OD). Great power and accelleration. But that subtle little shudder is driving me nuts. Any ideas?

Does it feel like a sort of random kicking on and off of the AC compressor in a 4 or 6 cyl car? You compare it to pulling a trailer but then use "shudder" to describe it. To me, a shudder is a lot different then the pushing/pulling that the trailer does on the hitch while driving.

If so, two of my cats have the same thing. One of them has a freshly rebuilt trans, the other probably has the original trans fluid.
So, I'll sit here patiently waiting for some leads.

Driving Shudder?

Reply #4 – June 28, 2006, 06:21:42 AM

Several thoughts I'll answer -

Quote

Improperly set/ loose TV cable. Don't know if that would cause a shutter though.

TV cable is good. Tight with no play. One of the first things I checked when I was having a cold engine "stumble".

Quote

Universal Joints in the driveshaft. Usually shutters when letting off the gas.

I'm familiar with this feeling. Did it in my truck. Not the same thing here.

Quote

Silly thought.. check your tire pressure....

New tires w/good pressure.

Quote

Does it feel like a sort of random kicking on and off of the AC compressor in a 4 or 6 cyl car?

This is the feeling I described feeling like the OD was kicking in and out. Have that at lower speeds.

Quote

You compare it to pulling a trailer but then use "shudder" to describe it. To me, a shudder is a lot different then the pushing/pulling that the trailer does on the hitch while driving.

Shudder may be a better term to describe "motor" issues. If you have a better word to describe this feeling I'm open for suggestions.

This car has 48K orig miles. New tranny fluid/filter. True duals/no cats. Idles, runs, shifts, accellerates great. The problem I am describing is subtle but noticeable. I still wonder if the code #32 I am pulling has anything to do with the driving shudder?

Driving Shudder?

Reply #5 – June 28, 2006, 11:14:13 AM

-have you thought of the dreaded ford torque convertor shudder. it was more common in the '90s but dirty fluid and certain convertors give that feedback. they used to come in the dealership by droves complaining about the way their car was running. svc mgr go for a ride and come back and tell me to set up enough trans fluid for a flush. once they changed fluid, test drive it with the customer, it was like having a new car again......but just food for thought....

Driving Shudder?

Reply #6 – June 28, 2006, 12:10:07 PM

I have already done the tranny fluid/filter change. This is my first experience with the AOD tranny. All my other Fords are or have been the C6. I can't tell if it's motor or tranny that's doing it - but it's subtle. I wish I could solve my code#32 to rule out that it is connected to my shudder issue.

Driving Shudder?

Reply #7 – June 28, 2006, 03:46:04 PM

Disconnect and plug the vacuum hose to the EGR valve. See if the trailer hitching goes away.

Driving Shudder?

Reply #8 – June 28, 2006, 10:36:50 PM

Quote from: sansabar

Shudder may be a better term to describe "motor" issues. If you have a better word to describe this feeling I'm open for suggestions.

I was just trying to understand if you had two types of symptoms or you were using shudder and trailer pulling to describe the same symptom.

I had a shudder in one of my cars with a C6 auto trans but the fix has already been stated and addressed here. I think of shudder as a short, rhythmic type of vibration, sort of like drifting over the white or yellow line that has those warning impressions in the pavement.

I currently have the trailer-pulling symptom now with two of my cats. Thing is, one of them has a rebuilt tranny so that makes me think it's the motor at least for that one. The other one, I don't know. I am curious though if we have the same symptom. It seems like we do.

Driving Shudder?

Reply #9 – June 29, 2006, 06:39:22 AM

Quote

Disconnect and plug the vacuum hose to the EGR valve. See if the trailer hitching goes away.

Tried it with no discernable diference. I had previously attached a vaccuum pump to the egr, pulled 15 lbs and the enginge began to stumble. Seems like the EGR is ok.

Quote

I was just trying to understand if you had two types of symptoms or you were using shudder and trailer pulling to describe the same symptom.
I currently have the trailer-pulling symptom now with two of my cats. Thing is, one of them has a rebuilt tranny so that makes me think it's the motor at least for that one. The other one, I don't know. I am curious though if we have the same symptom. It seems like we do.

How about bucking? The same symptom. My tranny feels good and tight - just downshifts a little hard if I'm light on the pedal. This is why I think it is motor related, too.

Some other things to note. This trailer pulling sensation seems to present itself at moments of decelleration or when I'm light on the gas. When I'm doing 65 or accellerating at a steady pace there seems to be none of this sensation.
Don't know if it is related but I am still having the momentary stall after first starting it up. It fires up fine, idles fine, go to give it gas and wants to stall. This lasts for about a minute or two - just until it warms up a bit. Again, the only code pulled is a #32.
This thing runs like a top other than these two little problems. Don't want it to turn into a big problem.

Driving Shudder?

Reply #10 – June 29, 2006, 03:22:29 PM

Quote from: sansabar

I had previously attached a vaccuum pump to the egr, pulled 15 lbs and the enginge began to stumble. Seems like the EGR is ok.

The EGR should open with 4-5 in.Hg.of vacuum.

Leak down test: Apply 5-6 in. Hg. of vacuum. Vacuum should not drop more than 1 in Hg. in 30 seconds.

Driving Shudder?

Reply #11 – June 29, 2006, 03:56:09 PM

i think i know what you are talkin about. its like the car shifts really hard and puses and pull like a trailer. its hard to explain,but it sounds like what my car does but mine also juggles gear when i am coasting an go to give it gas say on an incline and it doesnt know what gear to pick unless i mash it and make it kick down which cant be good for it but neither is it sitting there tring to pick a gear. might not be the same thing but does anyone know what causes that?

Driving Shudder?

Reply #12 – June 29, 2006, 07:07:46 PM

Quote from: softtouch

The EGR should open with 4-5 in.Hg.of vacuum.

Leak down test: Apply 5-6 in. Hg. of vacuum. Vacuum should not drop more than 1 in Hg. in 30 seconds.

Checked both. Opened with 4 in Hg and had no leak @ 6 in Hg over 1 minute.