Chromeshadow

I want to make sure I understand what is happening now, are these two problems still the same?
Have you checked the engine and transmission mounts? These are just rubber-so it should be easy to tell if they are shot. The 3.8 engine was a little harder to balance than a V8 and imho things that might not affect a V8 or inline 6 can be an issue with the 3.8.
If it does not throw a code, sounds like the engine is OK. Mine always had a very slight miss at idle, they run these as lean as they can to pass emissions. This sometimes results in popping when you let off the gas-this is usually an indication of a lean condition. Does it seem to have normal power?

SteelerNation82

The 2 problems mentioned seem to still be present. The mounts looked ok to me, the engine doesn't exhibit excessive movement when revved in neutral or park. I also had put the car in D w/ the hood up looking through the windshield and revved it slightly and the engine seemed to stay in place and not jump.

I think it's down a bit on power, when winding it up a bit feels like the delivery is just not there. I know this car has sat for extended periods of time, other than the p/o disconnecting the battery and then starting it up from time to time. Also, this car did have EGR codes when I bought it, and who knows for how long. I wonder if there's excessive carbon buildup inside the intake manifold ports. I know this can cause similar symptoms.

Chromeshadow

Could be carbon, I would expect that to throw a code. I'm wondering if it's still throwing a code, but your code reader is missing it, is this your code reader or are you going to Autozone or NAPA? might be interesting to try another code reader.

Have you tried to locate the noise any further? It's possible that you have a cylinder misfire at 1500 - 2500 PRM that just smooths out because the engine is rotating fast enough to mask it. This should show up soon if you pull the plugs and read them again....I would expect this to show up on a code reader unless something is just preventing the proper amount of air/fuel to go to one cylinder but allowing the correct mixture. Might be a problem with one of the lifters not opening all the time or even a worn cam. This might show up if you pull the valve covers and check each lifter. Collapsed catalytic converters can cause weird problems, you can often spot this with a vacuum gauge, as well as weak valve springs and other issues.
Here is a link with 15 vacuum gauge readings and their meanings: http://secondchancegarage.com/public/186.cfm

SteelerNation82

I have a Cen-Tech OBD II CAN reader I purchased new off ebay, same as this: http://www.harborfreight.com/http-ww...0794-html.html. Still trying to learn it and play around with the features. I have Torque app on my phone but it won't link to my car. I had to take a trip yesterday and put about 90mi on the car mostly hwy and noticed while cruising 50-55mph the vibration is pretty bad and to me almost unbearable, and I sense it being 'rhythmic' with sound waves if that makes sense. I feel it in the steering wheel, seat, dash/console, and all the lovely plastics rattle away. When I get up to about 70+mph it smooths out, but it's still there just much more subtle.

That code reader does live data logging/recording. I may give it a shot again today and see if anything rears it's head in it. Thanks for the link to the vac gauge diagnostics, I may have to pick one up as they're simple to use and useful.

BabyGT

This flutter sound is almost assuredly an exhaust leak, they all do it eventually, it was a poor design flaw from Ford where the ac condensation drains right on top of the passenger manifold, and cause cracking, which would cause it to sound like its from the passenger floor board.


Rpm based vibration could be due to worn u-joints in the drive shaft or worn tailshaft bushing. I'm experiencing the tailshaft bushing problem right now. Get the car up in the air and grab the drive shaft near the trans and give it a shake, there should be no play here. Same goes for the end near the diff. Make sure to grab the shaft and not the universal so you can make sure the universals are okay.

BabyGT

My car vibrates through the steering wheel it feels like at around 55-65 mph, at over that it smooths out.

Chromeshadow

Does your car still vibrate at these speed in neutral? With the OD button off? btw, the "waves" are usually a result of 2 sounds combining.

This might just be a tire out of balance, out of round, or a bad strut. You can usually see scalloped wear patterns on the tire if this is the prob. If you have a friend drive near you he/she might be able to see the problem tire bouncing.

BabyGT

It is not a tire or strut, all brand new, and there is just under about an 1/8th of an inch play in my tailshaft.

I know how to read tire wear patterns as well. As well as have swapped between 2 sets of tires and rims, same issue.

If he puts it in neutral and still has a vibration this still indicates driveshaft/rear end issues as a possibility, in neutral the rear will still be spinning the driveshaft and if a universal or bushing is worn the problem will still persist until he's below a speed that reverberates the driveshaft around whatever the problem is.

Its free to lift the car and man handle his shaft a little. Nothing to loose from it.

SteelerNation82

Although i can't say i've dropped the car in N while doing 70-75 but I did that test at speeds of 50ish and below, and noticed the vibration/shudder goes away. I've also driven with O/D off and get the excessive vibration but around 40-45mph which puts me within same RPM window where the vibration is most present.

SteelerNation82

I haven't really given the D/S or Rear a good look BUT if I'm just in P or N and rev the car while it's sitting to about 1500-2500RPM I feel the vibration in the entire cabin, as stated earlier(steering, dash, seat, etc). All of this points me to the engine, fwd of the TC...at least my opinion.