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Got Engine Vibrations??

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Old 10-06-2017, 08:40 AM
  #31  
SeanR
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$695.00 plus $18.95 shipped.

My car had an drivetrain vibration and I didn't make the effort to document what RPMs it occurred, it just seemed worse at cruising speeds, whether cruising at 2k or 4K, it was there and annoying. Some times it was worse than others. It was worse when the AC was turned on and had me thinking it was due to the AC compressor. Not the case it seems.

I'm still amazed at how totally smooth it is now. I mean really amazed. All rpms, speeds etc. silky smooth.
Old 10-06-2017, 09:50 AM
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FredR
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Originally Posted by SeanR
$695.00 plus $18.95 shipped.

My car had an drivetrain vibration and I didn't make the effort to document what RPMs it occurred, it just seemed worse at cruising speeds, whether cruising at 2k or 4K, it was there and annoying. Some times it was worse than others. It was worse when the AC was turned on and had me thinking it was due to the AC compressor. Not the case it seems.

I'm still amazed at how totally smooth it is now. I mean really amazed. All rpms, speeds etc. silky smooth.
Sean,

Just got back from a quick cruise up a local highway- local day off here so roads very quiet. I wanted to test the feel at different rpm ranges as I also have some unexplained vibration or perhaps better described as harshness. My motor mounts are relatively new [two years ago], the engine height seems OK, I had to pack the gearbox mounts with some rubber last year and that seemed to help a little vibration at the rear. At motorway cruising speeds it seems fine but once it gets over 4k rpm is feels somewhat harsh.

I have it in mind that given our heat and my 90S4 motor, I am suspecting the harmonic balancer. Question for you or anyone else playing along at home- does this sound like the kind of symptom a balancer past its sell by date might exhibit?

I have a relatively fresh GTS balancer in my parts bins somewhere. Just like to get some feel as to whether I have something brewing along the lines you had but possibly not quite as far gone.

Rgds

Fred
Old 10-06-2017, 09:54 AM
  #33  
SeanR
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Sounds very much like my experience. I'm going to be installing one in Jarrods GT in a couple weeks and he's had a bad vibration like what we are describing. Will update once that is done to see if his issue is fixed like mine was.
Old 10-06-2017, 10:04 AM
  #34  
FredR
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Originally Posted by SeanR
Sounds very much like my experience. I'm going to be installing one in Jarrods GT in a couple weeks and he's had a bad vibration like what we are describing. Will update once that is done to see if his issue is fixed like mine was.
Thanks- I have been following this particular issue for some time and been aware of the warnings that GB has been kindly advising about. Then the evidence of the consequences was plain to see on Jim's GT. I know that in our hot climate the issue is only likely to be worse and whereas low miles helps it is not the only factor in play.

Look forward to hearing about Jarrod's GT. I suspect this issue is just another one of those things on these cars where time is the driver that ultimately takes its toll. The problem is probably not really noticed on a motor one has owned for years because it just creeps up on you little by little.

There is also another factor- maybe this kit works better than the original so you get something fixed plas a bit extra?
Old 10-06-2017, 10:28 AM
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IIRC, it was $695 + shipping.

I paid and didn't blink twice. Well worth the money!

(This is what I get for posting without being fully awake. My reply is in response to the requests for price. Several posts ago...)
Old 10-07-2017, 01:18 PM
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FredR
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I think I might have got to the bottom of my harsh running- this afternoon as I parked up in the driveway to take a look at my side light status I noticed that something in the engine bay sounded a bit rough. Got the stethoscope out and eliminated all that I could, figured the sound was coming from the a/c compressor area, turned the a/c off and the sound "disappeared" - bummer!

We have local a/c shops that can rebuild these things - that or time for a new unit.
Old 10-07-2017, 02:15 PM
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Originally Posted by FredR
I think I might have got to the bottom of my harsh running- this afternoon as I parked up in the driveway to take a look at my side light status I noticed that something in the engine bay sounded a bit rough. Got the stethoscope out and eliminated all that I could, figured the sound was coming from the a/c compressor area, turned the a/c off and the sound "disappeared" - bummer!

We have local a/c shops that can rebuild these things - that or time for a new unit.
Probably just needs a new bearing. Mine was making all kinds of weird rattling and squeak noises. New bearing fixed it all.

Edit: just remembered it was making noise whether it was turned on or not. If it's only when turned on, that might be something more serious.



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