Clue (?): Shortly AFTERI paid a local shop to replace the oil pan gasket and water pump (both leaks fixed) I noticed a mysterious noise from under the car. Will hear nothing unusual for several miles then little bangs which get bigger, go away, come back without getting bigger, etc. The worst are loud and actually vibrate the driver seat. Recently I've noticed they are worse when turning, especially turning left. Yet at other times I can cruise and turn with no unusual sounds.
The car has been up on lifts three times looking for the source/problem and I've crawled under a couple more. No, there are no branches caught in in the undercarriage and there's no other obvious cause.
First diagnosis: the connectors between the rear sway bar and the A arms had evidently never been changed. They looked like skeleton connectors, pads worn almost away, and could easily be flopped back and forth. So with the guidance of Forum members I bought some new connectors and had them installed. Felt great when I drove away . . right up until the noise came back.
Second diagnosis: Guy showed me. The exhaust was rusted through in a few spots anyway, but it was also rubbing against the outboard metal of the "frame" (cradle?). A spot had been rubbed clean of rust. So with the guidance of the Fiero Store, I bought an Ocelot exhaust system and had it installed. Felt great when I drove away. Sounded better. Then I heard the noise come back. Another Clue (/) - the exhaust installer re-used by cutting and welding the flat metal support "studs" from the old exhaust onto the new: "They are already grooved to fit the mounting springs".
Third diagnosis: When the exhaust installer guy had the car up the second time, he noticed the connectors from the front sway bar to the A arms was loose on one side. Clue (?): I had replaced those connectors my inexperienced self a few years ago WITH both inner and outer tie rods AND the brass replacement for the steering rack bushing. The installation shop obtained replacements and installed. Felt great when I drove away . . right up until the noise came back.
Related? Exhaust installer also said the motor mounts are worn down and the engine might have more than normal movement.
I have another appointment with shop which installed the front connectors, this time to drive a mechanic around so he can listen.
Can anyone think of what I'm missing in this click- click, pop -Pop, bang-BANG, then quiet for a while mystery?
Iffy engine/trans mounts is very bad. Noise is only a Warring.
Engine moves can have: Pulleys and belt hitting Alt and other parts can break Exhaust will break Intake parts can break too w/ some engine like Fiero L4. Wires can make noise before shorts out or breaks.
If Trans moves Sideways etc, Inner CV(s) can have problems. When you turn, One Inner CV is compressed hard, Other is pulled out. Ether can made big binding and noise problems. Out out too far will destroy the CV instantly. The axle then destroy other parts and/or lock the wheel depending just what loose end of axle hits.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
I'm waiting now for the Fiero Store to open so I can order - and please check me on this - front engine mount ("after market", much less expensive than "OEM") rear engine mount two transmission mounts (stock type OK for 4T60?) "dog bone"
Fiero Store prices are reasonable. The Ocelot exhaust they sold me seems fine.
I'll suspend driving the 88GT until the slow and steady drive to the installing shop.
"Rubber" Engine/Trans mounts are ok. Many aftermarket are better then OEM but what TFS sells is any ones guess.
have no clue on engine mounts w/ Engine swap cars. I think 4T60 should have same as any other Fiero V6 AT. Brackets on both types should use same 2 mounts from posted here.
You're scaring me now. Let's just see if the clinks and pops disappear after the new engine and transmission mounts are installed. OR, I have some ear plugs . .
Add to the ever longer list of parts bought and installed in the pursuit of fixing the still mysterious clanking sounds under the 1988 GT (with 3.4 push rod and 4T60 trans): Motor and transmission mounts (including "dog bone").
Shop test drove car after new Fiero Store mounts installed. No clanks. Shop said the old mounts were really worn down. I drove the car home. More "dramatic" engine sound and nice vibration, as expected. No clanks! Great! Then at about seven miles the first little clink. Then more. Then the louder clanks, just as before. Clinks and clanks when driving level and straight but more when going through "dips" in the road. This time not such an evident increase in clanks when turning from our shared lane into our driveway.
Although the "best exhaust shop in Bloomington, IN" guy who noticed the motor mounts being worn down while installing the new (Ocelot, from Fiero Store - only source I could find) exhaust system obviously thought he'd done a great job hanging the new exhaust, I'm still suspicious of the exhaust system as a cause for the clanks for these reasons: 1) Clink/clank noises (and clank associated vibration which can be felt through the driver seat) ONLY START AFTER SEVERAL MILES, i.e., after everything is fully warmed up and fully expanded. The "best exhaust shop" guy showed me a rubbing point on the old exhaust before installing the new. 2) Exhaust installer re-used the same pieces (flat rectangular steel with notches to match the hanging springs) used by the old exhaust system by cutting them off the old and welding to the new. 3) More than a month ago while I was on my back under the car with a rubber hammer banging on everything I could reach, the sound which most resembled the while driving clanks was when I hit the exhaust near the engine.
Other information: the car has not had a catalytic converter since at least as far back as 2005. The new Ocelot exhaust only extended "from cat to back of car" so a new straight length of exhaust pipe tubing was welded in where the cat would have been located, just as was done for the former filler piece in the exhaust system which was just replaced. I don't know if the length of the old or new filler pipe was exact. A too-long piece mistake could have been repeated. Loose/worn motor mounts and resulting engine movement started the clinks/clanks by pushing/pulling against the exhaust system and compounding the mistake???
What do you think about arranging to pick up the exhaust guy and taking him for a ride AFTER the car is fully warmed up and clanking? He hears it, then we return and immediately put the car on a lift and look?
------------------ John W. Tilford
[This message has been edited by John W. Tilford (edited 04-25-2021).]
It sounds like one of your axles shafts is a little too long or too short. As the suspension cycles going over large bumps or turns, the inter tripot starts to angle and bind on the tripot housing.
Originally posted by fieroguru: It sounds like one of your axles shafts is a little too long or too short. As the suspension cycles going over large bumps or turns, the inter tripot starts to angle and bind on the tripot housing.
Or Trans have moved sideways doing same thing. As that can/will stretch one and compress other axle even rest not running.
Look at all pulleys too. If even 1 pulley is close to frame that should, brand engine/trans mounting allow a little sideways play and pulleys other things hit. Exhaust and some other parts grow when hot too and may hit somewhere.
Brake and suspension parts can do same when hot and noise is problem w/ them not engine problem.
The Meineke shop which just installed the motor/trans mounts said they "checked the CV joints" as I had requested and could find nothing wrong. Of course, I'm not sure how they checked or how much they know about Fiero short and longer axles. Probably more than I do. How could I or a professional check what you describe?
Also, I wonder how I could hear no clink/clank at all for the tens of thousands of miles since the 3.4 and 4T60 were installed until earlier this year? (Although, the extensive labor for changing the oil pan gasket and water pump and belt cover did suspiciously precede the noises.) And what would explain the several miles delay each time I drive it before the noises start?
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.
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
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.
------------------ John W. Tilford
[This message has been edited by John W. Tilford (edited 05-27-2021).]
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.
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.
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.
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.
------------------ " 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 "
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.
Fieroguru, theogre, reinhart, GKDINC, and Dennis LaGrua:
Do any of you know of a "Fiero smart" mechanic anywhere within reasonable driving range of Bloomington, IN? Someone capable of finding the source of the clicks and bangs?
As but one example of Fiero ignorance, one mechanic didn't know the 1988 suspension differences from 87 and earlier, e.g., rear stabilizer bar. Not a bad guy, just didn't know. Then his computer purchasing system didn't know there were connectors between the rear bar ends and the wheel hub assemblies - probably because the same computer system didn't know about the rear stabilizer bar either. The passage of a few decades seems to have wiped out Fiero expertise.
I had a banging noise on the passenger front of my 88. It turned out to be the passenger side coolant tube. Over the years it had moved forward and would clank on the frame sometimes. I loosened the clamps and moved it back about 1/2", no more banging.
I had never considered that at all. So my next trick is to make two mini-ramps out of old 2" X 8" wood, two layers thick, and put in front of my driver's side front and rear tire. Drive until on top. Set brake. Chock right side tires. Crawl under. Follow Larrylinkc's advice.
Issue unresolved after several months? And other issues were discovered along the way such as broken spot welds and other possible or unrelated discoveries? Here's my 2 cents.
Cent #1 Shortly AFTER I paid a local shop to replace the oil pan gasket and water pump (both leaks fixed) I noticed a mysterious noise from under the car.
My approach would be to backtrack what items had to be disturbed to accomplish the task of replacing an oil pan gasket and water pump. (Motor mounts & brackets, Dog bone, Starter and Exhaust components, assuming the engine was raised for clearance.
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".
This confirms the mechanic raised the engine and had no need to lower the cradle, so the cradle was not disturbed however its breath-taking to learn that merely gazing at the cradle bolts with the naked eye was assurance that they looked okay.
The GM dealer welder just looked at the cradle bolts and said they seemed OK.
It seems history repeats itself. First a mechanic and now a welder with the same miraculous gift of vision.
Again nothing was disturbed here. Move on.
And what would explain the several miles delay each time I drive it before the noises start
What are the road surface conditions several miles down the road when the noise starts and the rate of travel (mph)? Concrete, Asphalt, Gravel, Other? At what speed is the condition detected? Over 15, 30, 50 mph? Have you tried bringing the engine up to full operating temperature first and then driving down the same road to see if it makes the noise right away?
I would suspect the car was raised by some means such as a lift or floor jacks that were improperly positioned and some chassis or body components or both got damaged to include broken spot welds. It would be interesting to know if those welds had been broken a long time ago or recently which can be determined visually. Clean metal means recent versus rusty means a long time ago. Re-welding did not cure the problem long term but subsequent damage could of been done as well.
Cent #2 If I were you I'd offer to pay a Body Shop that is qualified and approved to do Insurance claim repairs go over your car checking for structure chassis damage that is visible and test drive it as well. To keep everybody honest you can also call several auto insurance companies and ask for a list of body shops that they pay claims for. Since they pay multiple shops I doubt they would recommend a particular shop. Auto collision shops see and fix damage on a regular basis. Those are the eyes I'd trust. Paid in full. Good luck on your venture. I'll be watching.
Spoon
------------------ "Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut
[This message has been edited by Spoon (edited 06-18-2021).]
'Just loosened the driver side coolant tube clamps, marked on tube with pencil on both sides of front clamp for reference, and gently tapped the tube rearward about a quarter inch. Re-tightened clamps. The tube was really close to the lower A-arm before moving. Not touching when cool, but I could imagine it expanding a fraction of an inch longer when hot. Won't have time to test drive until late 19 June or maybe later.
Spoon: I like the body shop idea. There's one a few miles away that has done work for me in the past. Most recent Fiero example: replacing front "hood" and right headlight components after a Bambi attack. That instance alone was a pretty good hit, but it was several years ago. I'm willing to pay them double - DOUBLE I say! - your two cent fee.
Back to the tube clamps: the rear-most, longer clamp has two 10mm hex head screws. When re-tightening, the forward-most progressively felt tighter then popped and was less tight as though I was screwing into one of those folded over spring metal clip deals and jumped a thread on the screw. The other two screws (one for the front, single screw clamp; the rear screw for the rear, double screw clamp) I could and did tighten firmly. I'm not overly concerned now, but wonder if there's an accepted way to correct, e.g., if both rear screws cannot be firmly tightened in the future.
As always, thank you both and all for your counsel. Let's hope moving the driver side coolant tube rearward will be the magic cure. I will report back when I have some information.
Thirty-five mile test drive this morning over a variety of surfaces. No discernible clink-clanks! Of course, was raining and windows were shut. Will take a longer drive this afternoon.
I can make the clicks/clanks worse by playing with the fore-and-aft positions of the coolant tubes, and somewhat better but not cured. Results from trial-and-error adjustments. Those double screw aft coolant tube clamps are right next to their respective left or right seat depressions, probably explaining why I can actually feel the bigger clanks through the seat.
We, the 88GT and I, may be visiting our Meineke friends. Going to check pretty much the entire front end with specific attention to anything which could possibly impinge with coolant tubes. And shocks probably worn out.
So far . . so good! Four around town trips and no more clicks and clanks. Meineke in Ellettsville, IN found three issues with front end and fixed. It's a pleasure to drive the car again.
Obvious with car on lift and wheels off and turning the steering wheel back and forth: there was near constant impingement/rubbing between outer tie rods and anti-sway bar. The "spacers" (go around threaded rods in connectors and set the distance between lower A arms and sway bar) were too short. Makes me wonder if some previous garage either ordered the wrong connectors or some parts dealer provided the wrong. Maybe the 84-87 counterparts are shorter than 88s. Installing correct replacements stopped rubbing.
Lower driver side ball joint was pretty loose. Replaced upper and lower on both sides. Meineke couldn't find upper replacements so I ordered all four from Fiero Store.
One of the passenger side front brake pads was missing its retaining spring. I provided from home stock.
I have been chasing down a kind of groaning noise on my 88 in the front end. It sounded like something metal was moving. I pried on everything I could get to and still could not find anything loose. Finally, I had the lower a-arms loose to cut a coil out of my springs and realized I had made a rookie mistake when replacing the bushings a while back. I had accidently tightened the lower a-arm bolts to the frame with the car up on the jackstands. The rubber bushings were put into a strain when I let the car down on the wheels. I would have never thought that rubber could sound that way when under a strain. I left them loose until I can run it up on ramps and tighten them with all of the weight on it. It`s quiet now with not a bit of noise.
