I have had a sense for a while initially during acceleration of a slight vibration not a wheel balance issue and supposed it was possibly binding Universal Joint. If this was right does this worsen to create a fairly loud almost banging at a low frequency interval in fifth and sixth gear which is not discernible in lower gears? Like a bang...bang... bang... never heard anything like this before.
Driveshafts spin at 2.65 to 4+ times wheel speed, so no, a driveshaft vibration would not be what I'd describe as low-frequency, especially in higher gears. Does it vary with load? Does it correlate with engine RPM or vehicle speed/driveline RPM?
Seems to increase in freq with rise in RMP but was just felt in 5th and 6th gear on highway... now I have a CEL and a rough idle so guessing a dead coil or stuck FI. The stomp code is just 1222 lambda left bank over and over.. being very cold in NEW England now I started getting the CEL at idle but as I warmed up it stayed out only it has since yesterday apparently come to stay . I just drove it and it was idling a bit rough so I'll check the injectors and coils... It had a couple of dead coils and stuck injector when I bought it and I grabbed the injectors off my other out to pasture 540 so have a few in the trunk...
The last couple of times I've had odd rhythmic vibrations in the driveline it was my guibo. Mine seemed to be at lower gear and speed though. I let it go on too long on one occasion and it literally exploded and took out my o2 wiring. Have you been able to check it for cracks and proper installation? There are small arrows on it indicating proper bolt orientation.
It has been ok for the last nearly 30,000 miles since I began driving it last August but I have not had it on a lift since getting this noise.. going to check into the coils and injectors in a few... as the idle was rough last night... could be two separate issues I really would hate to think the bang noise was a dead cyl because i drove it pretty long and hard but it did eventually smooth out slightly enough so I wasn't unable to drive a few hundred miles.. just first considered the driveshaft because there had been indication of some un-smoothness under acceleration at times which wasn't the engine and I thought it had just bound even tighter or whatever happens in the U Joints I'm sure the flex disc was oriented correctly but will check it asap for wear.
UPDATE: Looks like the rough running was a loose coil.. was held in with a screw in place of the original stud and the other stud was nutless so the screw backed out and the coil was hopping.. tightened it down and the engine was smooth..
Last edited by jehu; 02-14-2019 at 07:02 PM.
Engine smoothed out, but was that also your banging noise?
ummm it seems to be hard to say.. I still get some artifact at high speeds so maybe there is a wheel out of balance though I can't really recall how it could have occured since the last balancing.. I just drove it 400 miles and either its just a matter of really lousy pavement and the weak rear shocks are allowing all that through or I don't know it just seems to change enough without obvious changes in road surface to keep me from nailing it down but its not horrible enough to keep me from making a 400+ mile drive. I'll start with a check of the wheel balance next opportunity and go from there... I know I have a weakening right front wheel bearing/hub and have one in the trunk. I also have some new Black Powerlfex upper control arm bushings I want to put in.
Other than Tie rods and Koni Sports and strut mounts all the other steering and suspension stuff are what were there when I acquired it so the search goes on... I did think that banging I described was no longer apparent though so just the coil not sparking that plug and creating a miss?
Banging from beneath (trans tunnel area) under acceleration is a failed support for the driveshaft center bearing.
The bearing could be your noise, or it could be because the shaft is flailing around a bit possibly causing the joints to run at odd and differing angles.
Last edited by ross1; 02-17-2019 at 08:22 AM.
If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue
Last edited by jehu; 02-17-2019 at 11:36 AM.
Just brought the car in for a balance and rotation had been actually 6000 miles I drove that in less than a month and the rears were out quite substantially I assume from the way the inherent negative camber in the rear wears the inner part of tires and these are Michelin X ice three pretty soft compound for winter tire car is fine now after taking a spin on the highway
Last edited by jehu; 02-17-2019 at 01:49 PM.
spelling, grammar and punctuation make a lot of difference in the readability of your posts.
There's a difference between "Let's eat, Grandma" and "Let's eat Grandma".
Past that, you haven't said that you've actually looked at the giubo. If there are any gray threads hanging from it, or visible cracks, it's toasted. Sometimes you have to drop the exhaust, remove the heat shield, remove the six bolts on the giubo and the center bearing to be able to have it in our hands for an up-close-and-personal inspection. Other times, it's visibly a gray wazzle (technical term) and then it's REALLY toasted. I've seen both, you'll discover your path after actually inspecting it. Report back!
Charlie
Your mission, should you decide to accept it, is to add value to these threads, either by pictures or by descriptions, so the next person with the same or similar problem stands on your shoulders.
I've seen giubos that look like a rag tied to the driveshaft that still don't bang. If a giubo fails enough to bang it will do it once then you will be walking.
Banging under the trans tunnel on acceleration is almost always the center joint flailing around because the bearing support rubber is done.
If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue
The tire shop who balanced the wheels didn't have anyone to check that out so It'll have to wait till I get it on a lift in the coming weeks...
I am going with there was a misfire from the loose coil at the same time as the out of balance wheels which created this unusual phenomenon and after dealing with each of those that banging is gone and there is really not enough of any discernible vibration I can not comfortably attribute to slight weakness in perhaps some steering linkage like the center drag link or the upper and or lower control/thrust arm ball joints or bushings... or the weak rear shocks... certainly tolerable for long distance daily driving until I get around to closer inspection... I just drove it three hours again today to my uncle's wake and it was just fine..
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