Rattling noise from left rear that I can't figure out?
#1
Rennlist Member
Thread Starter
Rattling noise from left rear that I can't figure out?
I've got a rattle noise coming from my left rear that I can't figure out. It happens at lower speed (maybe up to 20-30mph) when the car goes over rough pavement, or a brick road. I had a pss9 fail early on where the top threaded shaft broke and the noise sounds more similar to that than say a body rattle like the aluminum skirt in the bumper, but the pss9 failure made noise at all speed when going over rough pavement. I've checked the aluminum skirt in the bumper, raised the car and shook every suspension piece, checked my monoball shock mount, checked the rear seatbelt receptacle, and even the metal center piece on my rs wheels. The only thing I haven't checked that I'm distantly suspicious about are the left side motor mounts, but everything is stable under heavy throttle, and it shifts smooth. Any suggestions?
thanks!
thanks!
#3
Three Wheelin'
May seem like a no-brainer, but did you check the plastic wheelwell splash guard for missing or loose screws? That could easily cause some rattling noises if not seated or tightened properly. I've experienced some rattles due to improper reinstallation after an oil change although thats the right side not left. A few minutes of readustments and the problem was solved! Hope its that easy for you.
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pp000830 (05-15-2023)
#4
Rennlist Member
Thread Starter
Chris, I have checked them in the past, and they feel solid when I shake them.
I've checked the plastic wheel well inserts also. I originally thought it was the aluminum shielding in the bumper, and worked on that, but didn't get any results from it.
I've checked the plastic wheel well inserts also. I originally thought it was the aluminum shielding in the bumper, and worked on that, but didn't get any results from it.
#5
Rennlist Member
My car had made a "graunching" noise from the rear at low speed going over expansion strips, etc. ... which I traced to the subframe bolts: correctly torqued and problem solved.
If the motor mounts are going, they droop: slowly jack the engine by the case seam, watching for ( excessive) movement at the exhaust tips as the car rises.
If the motor mounts are going, they droop: slowly jack the engine by the case seam, watching for ( excessive) movement at the exhaust tips as the car rises.
#6
solution?
I had a really annoying rattle for about a year, coming from what I thought was the right rear just behind the firewall. I would spend hours banging around underneath, removing cover plates, fender liners and such. The spoiler became a prospect, but no. Tried the interior nooks and crannys, under the rear window shelf, the rear seat belt spools...nada. These fruitless searches became a regular ritual. I was at the point that both my mechanic and I decided it was most likely behind the engine above the tranny. A depressing prospect.
After yet another frustrating session a few weeks ago, in desperation, I slammed my palm on the closed engine lid. Ddd d d. Whoa... what was that? Again... ddd d d. "Got you m%#@*^ f+!%r".
The two adjustable rubber buffers on the engine lid were screwed in so far that they did not create enough tension on the lid latch when closed. There was just enough free play to let the latch rattle when running on an uneven surface. Dumb.
From the drivers position, the apparent acoustical location of sounds is often misleading due to acoustic reflections and mechanical transmission paths.
rb
After yet another frustrating session a few weeks ago, in desperation, I slammed my palm on the closed engine lid. Ddd d d. Whoa... what was that? Again... ddd d d. "Got you m%#@*^ f+!%r".
The two adjustable rubber buffers on the engine lid were screwed in so far that they did not create enough tension on the lid latch when closed. There was just enough free play to let the latch rattle when running on an uneven surface. Dumb.
From the drivers position, the apparent acoustical location of sounds is often misleading due to acoustic reflections and mechanical transmission paths.
rb
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pp000830 (05-15-2023)
#7
Rennlist Member
Thread Starter
Has anyone ever noticed a rattling noise from bad motor mounts? I'll check them Garth.
rb- I really thought I had found it w/ the metal skirting in the rear bumper. Like you, I'd looked all over for the source, and I was detailing the car w/ an orbital buffer, and when I got to the left side of the bumper, it made a rattle similar to what I hear on the road. I thought for sure I'd finally found it, but my adjustments didn't make a difference. I will certainly check the latch though.
rb- I really thought I had found it w/ the metal skirting in the rear bumper. Like you, I'd looked all over for the source, and I was detailing the car w/ an orbital buffer, and when I got to the left side of the bumper, it made a rattle similar to what I hear on the road. I thought for sure I'd finally found it, but my adjustments didn't make a difference. I will certainly check the latch though.
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#9
Drifting
Dave-
Do you happen to have TRG rear sways on your car?
I had a similar issue that only made itself known on bumpy roads like Park Ave in Winter Park, etc. at low speeds and it turned out to be the left rear sawbar bushing assembly. My issues was more of slight knocking sound than a rattle, however. Just a thought.
Do you happen to have TRG rear sways on your car?
I had a similar issue that only made itself known on bumpy roads like Park Ave in Winter Park, etc. at low speeds and it turned out to be the left rear sawbar bushing assembly. My issues was more of slight knocking sound than a rattle, however. Just a thought.
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pp000830 (05-15-2023)
#10
Rennlist Member
Thread Starter
I wish it were something easy like golfballs!
I have the RS sways, and the drops links form the pss9 kit. I've tugged on the drop link and the bushing on that side, but didn't notice any looseness. My noise is more of a knocking than a rattle, and it's most noticeable over brick roads like downtown sanford / wp. Was your bushing noticeably loose? Do you live locally AC? I don't think I've seen your car around. Are you coming to the PCA meeting Monday night?
My exhaust tips seem level, and my shifting seems smooth, but I haven't looked at the mounts yet. I've always focused on the shock mount since I had the experience of the shock top failing once. I'll check them, and also that engine cradle everyone is talking about.
I have the RS sways, and the drops links form the pss9 kit. I've tugged on the drop link and the bushing on that side, but didn't notice any looseness. My noise is more of a knocking than a rattle, and it's most noticeable over brick roads like downtown sanford / wp. Was your bushing noticeably loose? Do you live locally AC? I don't think I've seen your car around. Are you coming to the PCA meeting Monday night?
My exhaust tips seem level, and my shifting seems smooth, but I haven't looked at the mounts yet. I've always focused on the shock mount since I had the experience of the shock top failing once. I'll check them, and also that engine cradle everyone is talking about.
#11
Addict
Rennlist Member
Rennlist Member
I had a rattling noise that seemed to originate in the engine compartment. It turned out to be a crack in the weld of the left muffler can.
Last edited by Dudley; 11-30-2008 at 07:40 PM.
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pp000830 (05-15-2023)
#12
Drifting
Dave-
I am in Winter Park, and cant attend Monday night. You havent seen my car around town in the past year b/c it has gone thru quite a transformation - and now it wont be street driven at all - ESPECIALLY Park Ave. type roads. :-)
What you are describing is exactly the kind of noise I had in my car. As it turns out the swaybar bushing couplings were way too tight on the bushing - causing them to bind and eventually "pop" or "knock" as they shifted on the bushing under load. Don at Zotz discovered this at some point, and since he loosened them up just a tad - the noise went away completely. Like you, it was only at low speed, not constant - but amplified on a cobble road like Park Ave.
Hope this helps.
I am in Winter Park, and cant attend Monday night. You havent seen my car around town in the past year b/c it has gone thru quite a transformation - and now it wont be street driven at all - ESPECIALLY Park Ave. type roads. :-)
What you are describing is exactly the kind of noise I had in my car. As it turns out the swaybar bushing couplings were way too tight on the bushing - causing them to bind and eventually "pop" or "knock" as they shifted on the bushing under load. Don at Zotz discovered this at some point, and since he loosened them up just a tad - the noise went away completely. Like you, it was only at low speed, not constant - but amplified on a cobble road like Park Ave.
Hope this helps.
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pp000830 (05-15-2023)
#13
Rehashing...
I have a slight bang coming from the rear left i believe. I can replicate it when I first load one side and then quickly flip to the other, like a quick AX turn. I looked around underneath and checked all suspension, and seems solid. Found the spoiler wall had split, so thought it was it sliding from side to side, but when I removed it, was still there.
Ideas?
I have a slight bang coming from the rear left i believe. I can replicate it when I first load one side and then quickly flip to the other, like a quick AX turn. I looked around underneath and checked all suspension, and seems solid. Found the spoiler wall had split, so thought it was it sliding from side to side, but when I removed it, was still there.
Ideas?
#14
Race Director
Thanks for bringing this thread back up.
My rattling has been at highway speeds sounding like it was coming from the LR wheel well. The remark about the deck lid rattling got me thinking as the noise seems to be more pronounced since I put on the RS Tail. And yes, the lid does move a little by hand. So I've dropped the rubber bumpers down a bit and will give that a try. Hopefully, that will be it. I will be ordering new deck lid stops anyway.
My rattling has been at highway speeds sounding like it was coming from the LR wheel well. The remark about the deck lid rattling got me thinking as the noise seems to be more pronounced since I put on the RS Tail. And yes, the lid does move a little by hand. So I've dropped the rubber bumpers down a bit and will give that a try. Hopefully, that will be it. I will be ordering new deck lid stops anyway.
#15
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And here's the kicker: I'm offering a unique set of vibration simulation mp3 files for free! They let you replicate the vibrations of a moving vehicle right from your driveway, making it easy to find the source of the rattle.
Check out the guide and let's make our drives peaceful again! https://9xx.com/products/9xx-vehicle...tion-mp3-files
Last edited by atwong1; 05-15-2023 at 10:18 AM.