tin type/rattle in trunk - any easy fixes?

Grubby · #1 (**permalink**) 12-31-2012, 12:07 PM

This summer I noticed a tinny type noise in the back of my car. It sounded like a loose piece of aluminum or steel. Most noticable when braking.

I was doing a few house keeping items to the car and i think I found the problem. If I pat the trunk floor the sound is pretty close to what I heard. The trunk floor makes a tin or rattle type noise.

Before I pull the fuel tank and see how to quiet this. Is it a known issue and how did you fix it?

John

mrmustang · #2 (**permalink**) 12-31-2012, 12:54 PM

I had this issue with one of my ERA's (I've owned a few

), pulled the tank and sprayed some plasticote bedliner in a can on the underside. Quieted down beautifully.

Bill S.

DanEC · #3 (**permalink**) 12-31-2012, 01:02 PM

I suspect you are focussed on the right area. When assembling my sheet metal I noticed the trunk floor aluminum was prone to tin canning and some noise. I put several strips of adhesive weatherstrip on the bottom side hoping it would brace off the top of the fuel tank but I didn't notice much improvement. I have a carpet kit for mine so I'm also going to put down a layer of B-Quiet 40 mil sound deadner before the carpet and hope that will take care of it.

I think some weatherstripping pieces on the bottom side would still do the trick but I apparently didn't use thick enough weatherstripping to sandwhich it solidly between the tank and floor (I think I used 3/8 inch).

Grubby · #4 (**permalink**) 12-31-2012, 02:23 PM

Thanks guys. I didn't really want to pull the tank, but thought I was going to have to.

John

strictlypersonl · #5 (**permalink**) 12-31-2012, 02:59 PM

If you can figure out how much clearance there is between the fuel tank and the trunk floor, try using some foam strips on top of the tank to take up the space.

LG57 · #6 (**permalink**) 12-31-2012, 03:30 PM

I had this problem with #134. The baffles in the tank had broken welds and were rattling around in there. Had a welding shop cut a hole in the top and reweld the baffles. Problem solved. Pulling the tank is not a huge deal and you'll need to do it anyway to install the sound deadner.

DanEC · #7 (**permalink**) 12-31-2012, 06:08 PM

John - you may be able to just loosen the bolts on the tank and let it hang down enough to be able to force some foam strips or pieces between the floor and the tank from the front. It may not be a perfectly neat application but should work until someday when you really need to pull the tank.

ERA 778 · #8 (**permalink**) 12-31-2012, 06:52 PM

While building mine, I tried to add soundproofing at places like the trunk floor since I expected some noise problems like yours. I used Dynamat on the back of the floor panel before I riveted it in. The stuff is designed to dampen out noises like this, so it should do a good job. However, with my engine running, I've never been able to hear much of anything!

I surely hope you don't have the broken baffle problem. That will be much more trouble to fix!

Grubby · #9 (**permalink**) 12-31-2012, 06:55 PM

There is 1/4" between the tank and trunk pan. I will pickup some dense foam strips at the hardware store and put 3 or 4 strips along the top of the tank.

I am confident the trunk floor is my noise. I can push on it and get pretty close to the noise I hear when driving.

John

bill37341 · #10 (**permalink**) 12-31-2012, 09:59 PM

I used 'Right Stuff' between my fiberglass panels and the aluminum panels on my inner fenders and boot area. Be sure you don't ever want to remove your tank, because this stuff really bonds these panels. Add a length of small diameter hose to the nozzle, because the can needs to be dispensed upside-down.Do not use the water-based stuff because it is very crumbly. Also USE VINYL GLOVES if you don't want to wear this goop on your hands for a week.Good luck, Bill.

Grubby · #11 (**permalink**) 01-01-2013, 05:00 PM

I purchased 1/2" thick by 3/4" wide foam strip, like used to seal old house windows. $3.47 at Walmart.

I put 7 strips running front to back spaced evenly on the bottom side of the trunk floor. Since the gap is 1/4" between the trunk floor and the gas tank, it should give plenty of force.

With everything back together I can't duplicate the noise I was getting. It is too cold and snowy to drive and give it the final check, but I am confident the problem is solved.

John

DanEC · #12 (**permalink**) 01-02-2013, 06:32 AM

That should do it. I may have actually used 1/4 inch thick weather stripping on mine instead of 3/8 inch. I have both types. At the time I thought if it was too thick it might bulge the trunk floor. But after riveting down the trunk floor I realized it needed to be thicker to be effective.

Grubby · #13 (**permalink**) 06-12-2013, 05:00 PM

Found it and fixed it --- finally.

I removed the aluminum panel that closes off my rear battery compartment and the problem went away. Drove it a few hundred miles with no noise. It seems odd that it would make noise since it was held in place with Velcro.

I just put sound deadener on the inside of the panel. The same stuff used on ERA foot boxes and trans tunnels. It seems to be fixed.

It is nice to knock the little things out.

John