Clunking Noise Behind Seat/Under Car

alpace@pacificp · #1 (**permalink**) 04-21-2008, 11:14 PM

Good Day all,

I am desperately attempting to sort out a 'clunking noise' behind that emanates from the panel behind the seats. The racket increases with speed, and diminishes as it decelerates. I have lifted the vehicle, looked underneath and cannot identify any obvious issues..but frankly, might not know the problem if I saw it!

The Kirkham folks were great, picked up the car and took it back to Provo, but when it came back, the noise was still there...and appears to be getting louder. The sound is as though there is a slight pounding on the panel located behind the seat?

Anyway, I spoke with Joe and he suggested I bring it into a solid local mechanic. As I do not want to drive it very far (safety/damage concerns), I am hoping someone has a couple of local (San Mateo, Redwood City/San Carlos/Millbrae, SOuth CIty contacts that they could pass along?

Any thoughts would be most appreciated as at this juncture I have had the car for four months....and the issue persists.

THANKS IN ADVANCE!

al

xlr8or · #2 (**permalink**) 04-21-2008, 11:23 PM

Wheel weight hitting the caliper? Ebrake cable touching the drive shaft.
If it's rythmic it is something rotating. If it's not it's something flopping around.

Pull the tire and shock, set the suspension at ride height and run it around by hand or with the engine.

alpace@pacificp · #3 (**permalink**) 04-21-2008, 11:31 PM

Xlr8r,Good thought about pulling the wheel and rotating...though the sound really diminishes once I am down to about 5 mph...I am wondering about your suggestion that something might be rubbing against the drivetrain...hmm.

al

Murphy · #4 (**permalink**) 04-22-2008, 05:42 AM

You describe a sound I had. I found that the rectangular flat aluminium panel at the front of the trunk to vibrate and make a strange sound. If you look in the trunk you will see it. I took mine out and put adhesive foam tape on it where it contacts.

alpace@pacificp · #5 (**permalink**) 04-22-2008, 08:20 AM

Murphy,

I will check that out! Thanks!

al

xlr8or · #6 (**permalink**) 04-22-2008, 09:06 AM

Yep that forward floor panel in my trunk made noise too. I just put some Dynamat on it when putting in carpet.

Also make sure your coil springs are clear of the U-joints.

kurtmart · #7 (**permalink**) 04-22-2008, 09:26 AM

Alpace,

There is a panel behind each wheel in the fender well on KMP SCs. It needs to be braced on the rearmost end or it wobbles and makes an oil can kind of noise. A small wood block glued in works good. Also look to tightening the arm that holds the trunk open and while your at it check that the hood brace is tight too.
I just finished pulling out the seats and carpet dynamated the interior (None next to the gas pedal, it's to thick there) sealed the aluminum seams and had a boot made for the E Brake with it's hole into the tunnel, it is like frikkin night and day. No more exhaust in the cockpit, 90% of squeaks and rattles gone a way less engine heat coming in.
Have fun

Kurt

Jamo · #8 (**permalink**) 04-22-2008, 11:33 AM

Sounds dumb, but pull your access panel in the trunk and make damn sure the upper bolts for the third member mounting to the frame haven't backed out a bit. They won't fall all of the way out, but they will loosen and allow it to shift a little...made a sound like you're describing.

Mine did this once. Blue Locktite muy goodo.

Also check the wires going along the inside of the top of the front of the trunk...they can bounce a bit on the arruminum and sound like a drum.

Lew Ledyard · #9 (**permalink**) 04-22-2008, 11:50 AM

Is there a bowling ball in the trunk?

FatBoy · #10 (**permalink**) 04-23-2008, 01:43 AM

Al,
It's worth checking the inner UJ's on the half-shafts. Mine fouled on the edges of the holes in the side plates on the chassis (the large holes that the half-shafts go through). The driver's side was fine but the passenger side fouled to the extent that the wheel wouldn't turn. I had to take the corners off the UJ's and attack the side plates with a Dremmel to get clearance.
There still isn't much of a gap, so I'm hoping the diff. doesn't move about too much under hard acceleration and deceleration.

Paul

mrmustang · #11 (**permalink**) 04-23-2008, 03:34 AM

Sounds even stranger, but check the routing of your emergency brake cable, as I worked on an older ERA (009 I believe) where the cable was held in place above the driveshaft with a large zip tie. When it broke, it allowed the cable to just touch the driveshaft causing the same type of noises in which you describe. Have never run across this in any other car, but it is worth a shot in your case..........

Bill S.

alpace@pacificp · #12 (**permalink**) 04-24-2008, 11:37 PM

Hello All,

Just want to thank everyone for their thoughts on my 'clunker'! Tomorrow, it is up on a rack with a reputable mechanic. We will take a look with hopes of resolving. I have printed out all of your thoughts/suggestions in the hopes of isolating the problem. I will keep you posted!

On another note, took car to CHP for inspection and Vehicle ID. Went well, etc., though officer noted valve covers and front of engine oil pan was leaking! Spoke with Joe at KMP and he stated this was not atypical. Hope to have mechanic torque the bolts tomorrow and stop the seepage.

I have my SB-100# in hand and am looking forward to resolving these niggling issues so that I can drive VNMS 65 without worry....

Regards!

al

Bill Bess · #13 (**permalink**) 04-25-2008, 07:27 AM

Al, these kind if things can drive a sain man crazy, cause a loss of sleep and drive you to drinkin too much.
Its a process of elimination to find these little things and takes time, here are my suggestions.

Does the noise happen while coasting and the car in nuetral?
or in gear?
Put it on four jack stands so the driveline is free to operate.
Spin each wheel by hand and with power.
Check driveshaft clearances..is anything touching?
Check all panels if the noise isn't driveline related.
Is anything rubbing?

Last resort....let is wear in, wear out..when it gets really bad the car will break, and then you'll know (Sorry, just joking)

I had many little strange sounds when I first got my car going, but one by one I have eliminated them.
Best of luck, Bill

alpace@pacificp · #14 (**permalink**) 04-25-2008, 08:29 AM

Bill,

Thanks!

I am on my way to Automotive Specialists this morning. We are going to get the car up on a hoist and take a look see. My hope is to rule out drive-train and rubbing cable(s) e-brake as the culprit. After that, I guess I take a closer look at the trunk panels, cables that run through there, etc.

Wish me luck!

al

alpace@pacificp · #15 (**permalink**) 04-28-2008, 10:26 AM

Mr. Mustang, et al!

Turns out is was the emergency brake cable/assembly. Brushing against rear wheel, causing some scoring of wheel, etc.

Kirkham (Joe Weight) is all over it...working with my guy at Auto Scientific to resolve. New parts being shipped as we speak.

Can't wait to get the machine back. Weather has warmed up nicely!

Thanks everyone for your help. What a great resource this is!

al