What else could clanking noise BE? (Page 2/3)
John W. Tilford APR 25, 11:17 AM
theogre,

'Just saw your reply. Sounds like we're back to checking all clearances and rear suspension/axle length geometry and exhaust.

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John W. Tilford

John W. Tilford MAY 27, 08:13 AM
GKDINC and theogre and anyone else:

Finally found a possible cause - or maybe just a result - of the clicking and banging. Here's an image showing where apparently at least two spot welds have failed and the layer of steel closer to the smart phone camera has been sliding against the layer underneath:

Back side, as seen from the left rear wheel well. Seam is just to the right of the two wiring protector deals:

The location is behind the driver seat and near the outside of the car. The mechanic who spotted this was able to use a small crowbar and move the closer metal up and down. The counterpart seam on the other side of the car is fine.

I've got an appointment a week from now for the local GM dealer body shop to try to weld. Doubt they can access well enough to drill and replace spot welds, probably wire weld along the seam on both sides, maybe add a short piece of angle steel and weld that over the seam.

BUT, is the failed seam the cause of the noises or one result of the banging? The 3.4 has additional torque, sure, but enough to cause this? I doubt it. Or do these spot welds just plain fail sometimes?

Remember the clicking/banging only occur after a few miles. Drives like a proverbial dream until that with no unusual noises or vibrations. The loudest bangs I could feel under my butt.

Appreciate your thoughts.
GKDINC MAY 27, 10:32 AM
I have a question. After the clicking,banging sounds starts is the noise still there with the car in park and running? Or do you have to be moving to hear the clicking and banging? Good Luck Gary
John W. Tilford MAY 27, 04:34 PM
Gary (GKDINC),
1) Only when moving
2) Only after a few miles
3) Sometimes associated with bumps in the road like RR tracks, sometimes not.

Maybe a clue: car consistently popped and banged on our shared lane when I returned home after the "several miles" drive prerequisite had been met. The lane is crushed stone with gazillions of little bumps giving a vibrator effect.

Regarding flex plate: no start up odd noises or apparent starter to ring gear issues.

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John W. Tilford

[This message has been edited by John W. Tilford (edited 05-27-2021).]

reinhart MAY 28, 08:28 PM
If the welding doesn't fix it, check the cradle to frame bolts and that looks like original rubber suspension bushings. Either of those could cause that.
John W. Tilford JUN 07, 04:24 AM
Reinhart,

Local GM dealer/suspension portion of service guy/"collision" shop welder guy (and they let me under the car while up on lift before they started and after they finished)

1) welded both sides of "break" illustrated above. Their better lit and angled view of the back side showed an actual gap between the layers of steel. Painted black after welding. I did not see the pre-paint weld, Hope it was sanded/wire brushed/whatever.

2) I asked the body shop guy doing the welding to also test/check around the four corners of the cradle, which he said he did. His words [paraphrased] "I didn't actually use a torque wrench but they looked OK".

Anyway, no clicks or bangs in the last three trips to town and back, average 8 miles one way. I'm still holding my breath.

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John W. Tilford

reinhart JUN 11, 04:30 AM
Sounds like that did the trick. Awesome.
John W. Tilford JUN 11, 08:32 AM
reinhart,

Heard some of the same clicks and a mild bang yesterday. Crap. Much better, but still frustrating/disappointing. Makes me wonder exactly what I'm risking by driving the car. Takes the fun our of driving. I wonder what caused the spot welds to break in the first place.

What do you think about taking the car in to the last shop which actually lowered the cradle (I assume they would have had to) to replace the oil pan gasket and install new water pump, new belt, and new gasket around water pump etc. belt cover. All the leaks were fixed, but the click/clank/bang noises started after that work. Ask them to check each corner of the cradle? The GM dealer welder just looked at the cradle bolts and said they seemed OK.

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John W. Tilford

Dennis LaGrua JUN 11, 10:03 AM
Clanking noises can also emanate from a loose part in the exhaust or suspension system. Make a simple stethoscope from a funnel and a length of heater or garden hose. Duct tape the funnel to one end and that is your listening piece. Have an assistant rock the car and listen around. Also check the steering rod ends for excessive play.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

John W. Tilford JUN 16, 09:17 AM
Guru, GKDINC, and Dennis LaGrua:

The last few times ("few" is right. The clink/clank noises have taken the fun out of driving the car as has the fear of causing serious damage.) I've pulled into the home garage, specifically front tires over the ridge behind the door opening, I've heard mechanical noises which seem to be from the front end. Yesterday, I heard a front end noise when the car first moved backwards as I left the garage, and it was not warmed up at that time, just started the engine and backed up.

Wondering if one or both of the front brake pads are dragging too much on the disc/s and then causing some moving forward clearance problem when hot. No, I do not drive with my foot on the brake pedal. (GKINC, remember the noises do not start until after driving a few miles. Hard to use diagnostic listening devices while driving.)

Also, amateur me replaced both inner and outer tie rods about four years ago. Replaced the original plastic passenger side rack bushing with brass at the same time. Put two screws into the brass to fix in place. Wondering if I screwed up something which is just recently producing the "after a few miles" noises. I recall having a difficult time tightening something on the end of the rack . . . I had to turn a tool (borrowed from O'Reily's (sp?) or Advance Auto or similar place) which fit around a wide, hexagon shaped end with a regular socket driver at the other end. I was between shoulder surgeries at the time and shooting pain due to the weird angle of arm and tool compounded by twisting motion was a problem.

I can't understand how a front end clank/bang could - rarely - seem to travel back to my seat, but, as they say, the foot bone's connected to the ankle bone, etc.

Back to the flex plate theory: there are ticking noises from the engine when first started. Usually much less evident later. I assumed it took a while for enough oil to get to the push rods, etc.

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John W. Tilford