5 replies to this topic

[rkctdwn]

Terry hoping you might have heard just exactly what this 8lb chunk of cast iron was specifically intended? I'm guessing it's trying to cancel a harmonic in the body or a drive train noise.
I'm chasing thunking noise seems to be the exhaust pipe bouncing since putting on new struts this noise which I was hoping was being caused by weak rear springs and original rear struts. I can find no marks on the exhaust pipes actually hitting anywhere. It's almost as if it's a function of the hangers???? My early 98 Mystique LS ATX built 07/97. The noise is only on sharp quick type suspension travel like concrete streets where maintenance is long over due. Rockford,Il. visiting the grandson last week really brought out the noise.

It's not the heat shields-more of a heavier thunk when bounce/struck with my fist in the hanger area under the driver-side passenger. The mounts for the drag links tight,tank straps tight and I removed this cast iron NVH weigh-drove it not near as bad. Haven't noticed any droning noise while driving except when I back up (Rev)turn wheel to right ok to left Ooow I hope that's not something starting to go IE wheel bearing pass-side?
I started replace the rubber exhaust hangers last winter and this when the noise became more noticeable???? I'm using the proper Walker hangers the smaller 3ea in the middle and two larger 1ea rear of muffler and 1 ea by the cat/flex pipe.
It sure be nice to have a lift!!!! AH NVH where the computer modeling program EH? This is still all original factory, I've got the crazy idea with age, corrosion not bad as in heavy, metal fatigue the system as a whole moves/flexs with different moments than new??? With economy I'd really be crazy to replace with all new just to find out It's still quite! The bean counters only knew they could have shaved a few more pennies of cost?
I just remembered, I think, this was only on ATX cars????
Thanks Sir Terry!

[Terry Haines]

..one of the rubber hangers should be red,it is a softer Si material...What type of connection do you have to the Y pipe?..Sounds like it got worse since the exhaust work?..

[rkctdwn]

Terry Haines, on 03 August 2011 - 07:10 AM, said:

..one of the rubber hangers should be red,it is a softer Si material...What type of connection do you have to the Y pipe?..Sounds like it got worse since the exhaust work?..

Ah yes the red hanger up front close the the cat, I did replace it, I thought that was silicone for the heat? My Y-pipe is bone stock factory and appears to be tight.
Terry the noise I can actually feel in drivers seat sometimes, that what has be puzzled one would think some sort of wear mark would be seen. Oh the cast iron weight what was that trying to cancel? Sorrrry for trying to stress the memory, I know how that is! If that was not in your area engineering I surely understand. Amazing how many different areas/engineering groups are involved. since I'm a detail type of tech what the engineer was trying to achieve has always peaked my interest!
Back in the early years of the CEG web site when there were Ford engineers and Vieston guys on the site that detailed stuff was out there until ole what his CEO at the time put a stop to that,at least thats how I remembered?
Thanks so much for taking to time Terry!

[Terry Haines]

..cast iron weight?..OK some NVH dampers were fitted but which one do you mean? BTY the Y pipe to main exhaust must not be solid.If you have the 2 bolt type with a seal and springs it is designed to move with engine roll and not use the exhaust as a roll restrictor etc..

[rkctdwn]

Terry Haines, on 03 August 2011 - 12:19 PM, said:

..cast iron weight?..OK some NVH dampers were fitted but which one do you mean? BTY the Y pipe to main exhaust must not be solid.If you have the 2 bolt type with a seal and springs it is designed to move with engine roll and not use the exhaust as a roll restrictor etc..

Ah yes Terry it be much better if I had pictures instead my words,that I loose my train thought no matter how many times I proof read, I still manage to confuse!!! Ah yes the flex-pipe the woven mesh that reminds of huge cylindrical mesh type ground strap! It ok! Oh I guess you didn't understand my prose the system is factory original except for the rubber hangers! Amazing after 14 years in Ohio winters, good ole Rust'Oleum zinc coating. Primer and a zinc rich top coating both act like a sacrificial anode or is that cathode? Does matter it's not the answer the salt eats it off before winter is over. Not sure if Por-15 makes a coating exhaust or not? See that's up to $100+ gallon now?
Yeah this weight hangs on single bolt bracket below the right side emergency brake cable bracket. In the center tunnel area with the exhaust pipe. As I said before I was thinking only ATX tranny cars used this NVH weight,
Drove car again this afternoon and the intensity of the thunk is reduced without the weight???? Had to believe the age,corrosion and metal fatigue could have changed enough BUT????? That's why I was curious what all the weight was designed to correct?
I know why you never understand me the right-off,I haven't the foggiest the east London dialect!EH? As you can tell I don't even know the proper terminology,I've term before by Hams in the area discussing AH my ole forgetter!

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[rkctdwn]

rkctdwn, on 03 August 2011 - 06:10 PM, said:

Ah yes Terry it be much better if I had pictures instead my words,that I loose my train thought no matter how many times I proof read, I still manage to confuse!!! Ah yes the flex-pipe the woven mesh that reminds of huge cylindrical mesh type ground strap! It ok! Oh I guess you didn't understand my prose the system is factory original except for the rubber hangers! Amazing after 14 years in Ohio winters, good ole Rust'Oleum zinc coating. Primer and a zinc rich top coating both act like a sacrificial anode or is that cathode? Does matter it's not the answer the salt eats it off before winter is over. Not sure if Por-15 makes a coating exhaust or not? See that's up to $100+ gallon now?
Yeah this weight hangs on single bolt bracket below the right side emergency brake cable bracket. In the center tunnel area with the exhaust pipe. As I said before I was thinking only ATX tranny cars used this NVH weight,
Drove car again this afternoon and the intensity of the thunk is reduced without the weight???? Had to believe the age,corrosion and metal fatigue could have changed enough BUT????? That's why I was curious what all the weight was designed to correct?
I know why you never understand me the right-off,I haven't the foggiest the east London dialect!EH? As you can tell I don't even know the proper terminology,I've term before by Hams in the area discussing AH my ole forgetter!

Anyone else out there ran into noise/thunking from the exhaust system? As I said before it's not hitting metal just seems to movement within the rubber hangers travel. I never thought this could produce this type of noise. These are "Walkers" brand hangers. Have to check with dealer to see if the original are still available, frustrating can't believe this would be so sensitive.