Disturbing sounds from right rear area - loose gas tank?!
03-20-2002, 12:55 PM
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Disturbing sounds from right rear area - loose gas tank?!
Hello,
I have a strange problem that is starting to worry me and I was hoping someone here might be able to help. For awhile now, I have been hearing an odd sound when backing out of my sloped driveway in the mornings. The sound is something like metal scraping against metal. I can also sometimes reproduce this by taking my turns a little extreme. This morning, I made a hard left from a stop and I heard a really loud thump from the same right rear location, like someone threw a baseball at my baby. A mile down the road I smelled gas for a minute, but it went away. This made me think that maybe the sounds I have been hearing is my gas tank sliding and moving around. I sometimes get a gas smell after filling the tank and parking, so combined with the odd sounds coming from the gas tank area, I am suspecting this is the culprit. Has anyone else experienced these symptoms and can tell me what the cause was? Can anyone tell me my suspicions are whacked or right on? What to do?!?!
Thanks in advance for any and all suggestions.
I have a strange problem that is starting to worry me and I was hoping someone here might be able to help. For awhile now, I have been hearing an odd sound when backing out of my sloped driveway in the mornings. The sound is something like metal scraping against metal. I can also sometimes reproduce this by taking my turns a little extreme. This morning, I made a hard left from a stop and I heard a really loud thump from the same right rear location, like someone threw a baseball at my baby. A mile down the road I smelled gas for a minute, but it went away. This made me think that maybe the sounds I have been hearing is my gas tank sliding and moving around. I sometimes get a gas smell after filling the tank and parking, so combined with the odd sounds coming from the gas tank area, I am suspecting this is the culprit. Has anyone else experienced these symptoms and can tell me what the cause was? Can anyone tell me my suspicions are whacked or right on? What to do?!?!
Thanks in advance for any and all suggestions.
03-20-2002, 02:37 PM
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Erik, I don't know if it's the gas tank. I had the education of removing mine and cleaning it. The tank is plastic and it is held on by four straps that are brought together on the bottom in a web. Crawl under there and tighten the four bolts that attach to the car and see if it's loose. It is not hard to do (13 mm if I remember correctly). Then see if there is something loose in the area under the fuel pump cover (10 mm nuts two of them). Go to 928 Specialists web page for directions on how to remove fuel pump cover. Then you could also look in the fuel tank by removing fuel level sender. Might want to disconnect battery for this part to be safe. Good luck. <img src="graemlins/a_smil17.gif" border="0" alt="[blabla]" />
03-20-2002, 02:55 PM
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Good point. Of course it can't be the gas tank because it couldn't possibly have been made of metal. I will look to see if the straps have loosened, but I suspect now that something structural is to blame. Has anyone experienced failing shocks or springs that exhibit the kind of behavior I described? I can imagine a spring that has been sort of "stuck", then under duress it frees with a loud thump. When the spring has slightly more play, but almost "stuck" it makes the metal scraping noise. Does this make sense? Any other thoughts?
03-20-2002, 05:29 PM
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Very interesting problem and thread. Please update us on your final solution!
Here's my theory: You have two problems operating simultaneously.
Problem #1) Possible bad wheel bearing in the rear. To check for this, jack up the right rear, grab the tire from the top and bottom and rock firmly. If you hear a clunk then the bearings must be replaced. Apparently, they cannot be adjusted. Some say they can be tightened with proper equipment, however. Unsure on that.
Problem #2) At the same time, you may also have a bad fuel level sender gasket. If you smell fuel after filling up and taking a few hard corners, fuel can slosh out the top of the tank past the top of the sender if its gasket gets stiff. It's a $2 part and replacement is easy.
Lift up your hatch carpeting and check out the area. The RR shock tower mount should be visible. Take a look at that while you're there regarding your possible suspension-related problem.
For the fuel problem, do this only after you smell fuel again (probably after some hard cornering with a full tank). Lift the circular black plastic cover from the opening in the rear deck. Check around the top of the fuel tank and on top of the sender itself for fuel. If the gasket goes bad, fuel can leak out of the top of the tank.
Other Thoughts:
Like Chucker, I've removed/reinstalled the tank and the fit is incredibly tight. There's no way your tank could be moving around side-to-side to cause the noise. At most, you might have a slight up/down rattle if the padding on the tank straps has been eaten away. But still, I don't see it.
OK, let us know what happens!
Dan
Pasadena, CA
'83S
SOCAL928
Here's my theory: You have two problems operating simultaneously.
Problem #1) Possible bad wheel bearing in the rear. To check for this, jack up the right rear, grab the tire from the top and bottom and rock firmly. If you hear a clunk then the bearings must be replaced. Apparently, they cannot be adjusted. Some say they can be tightened with proper equipment, however. Unsure on that.
Problem #2) At the same time, you may also have a bad fuel level sender gasket. If you smell fuel after filling up and taking a few hard corners, fuel can slosh out the top of the tank past the top of the sender if its gasket gets stiff. It's a $2 part and replacement is easy.
Lift up your hatch carpeting and check out the area. The RR shock tower mount should be visible. Take a look at that while you're there regarding your possible suspension-related problem.
For the fuel problem, do this only after you smell fuel again (probably after some hard cornering with a full tank). Lift the circular black plastic cover from the opening in the rear deck. Check around the top of the fuel tank and on top of the sender itself for fuel. If the gasket goes bad, fuel can leak out of the top of the tank.
Other Thoughts:
Like Chucker, I've removed/reinstalled the tank and the fit is incredibly tight. There's no way your tank could be moving around side-to-side to cause the noise. At most, you might have a slight up/down rattle if the padding on the tank straps has been eaten away. But still, I don't see it.
OK, let us know what happens!
Dan
Pasadena, CA
'83S
SOCAL928
03-20-2002, 06:26 PM
#5
Three Wheelin'
Erik,
I would be looking at the "metal-metal" noise possibly being:
1) tire rubbing on something. Check all around wheel housing and tire for any signs of tire touching.
2) if the rear shield for the brakes (1/2 round pie pan looking thing),is broken or bent, it can rub on the rotor. It makes a real metal-metal sound. Mine was in that condition when I bought the car. It scraped against the rotor.
3) I had a broken parking brake shoe retaining spring which was floating around in the drum. If you have a broken retainer, maybe it repositions when you go in reverse and grinds on something.
Greg
I would be looking at the "metal-metal" noise possibly being:
1) tire rubbing on something. Check all around wheel housing and tire for any signs of tire touching.
2) if the rear shield for the brakes (1/2 round pie pan looking thing),is broken or bent, it can rub on the rotor. It makes a real metal-metal sound. Mine was in that condition when I bought the car. It scraped against the rotor.
3) I had a broken parking brake shoe retaining spring which was floating around in the drum. If you have a broken retainer, maybe it repositions when you go in reverse and grinds on something.
Greg
