thumping noise in the rear????

[dennisdrive]

Hi everyone ,I got a salsa 2004 vibe with the power & sports package and it has been abt 4 1/2 months on road .I dont drive on a day to day basis and to date the tachometer is abt 3400 .But off lately there has been thumping sounds in the rear each time the vibe drives over gaps or small pot holes on the road .On smoother roads it is pretty quiet .Is it unusal or usual for this .It wasnt that obvious in the 1st 2-3 months.Could this be rectified if i try to tighten the spare wheels (which i havent checked so far) or could it be something else ??By the way the tire pressure are all at the specified 32 psi.

[dennisdrive]

i inspected the spare tire ;though it appeared secured i did tighten the bolt and also the bolt over the over also checked the cargo tray .It appeared to be quite in place .As i was abt to close the trunk i noticed that the cover of the rear light assembly was a bit loose on both the sides .I secured them in place and checked the tire pressure again which were at 34 psi so i lowered them to 32 .Took it for a rest drive and it appears to have quietened down .Will let you know as to how it drives over the weekend .Thanks for the early reply "silverawd26" and thanks to this site too .Have learnt so much abt my vehicle from here . GEN VIBE It does make life SWEET !!

[DaddyVibeMI]

Quote, originally posted by dennisdrive »i inspected the spare tire ;though it appeared secured i did tighten the bolt and also the bolt over the over also checked the cargo tray .It appeared to be quite in place .As i was abt to close the trunk i noticed that the cover of the rear light assembly was a bit loose on both the sides .I secured them in place and checked the tire pressure again which were at 34 psi so i lowered them to 32 .Took it for a rest drive and it appears to have quietened down .Will let you know as to how it drives over the weekend .Thanks for the early reply "silverawd26" and thanks to this site too .Have learnt so much abt my vehicle from here . GEN VIBE It does make life SWEET !!Congrat! Problem Solved!

[DavidPIL]

Hi dennis...Depending on the time of day and if the car was in the sun, you probably shouldn't have lowered the air pressure in the tires... not that it was the cause of your issue.Since air pressure should be checked with the tires cold - early morning is best or if the car is garaged - if you checked the air pressure, lets say mid-day, the ambient air temp was probably 15-20 degrees warmer than morning temps which would account for the 34 psi instead of 32 psi. Just driving the car for a few miles could add up to 4 psi. This is not only from my experience but also similar to what's posted in technical portions of sites like tirerack.com, tires.com and 1010tires.com.Dave

[dennisdrive]

Hi David ;Thanks for your advice .I checked the tire pressure when they were cold .And i drove to a nearby gas station which is less than 0.5 km from my place and filled air and then checked and adjusted the air pressure .And y'day i did drive to pick my wife from work about 24 kms both way and the noise did quieten down a bit but when the road is pretty rough it does make some dull noise .Is it becoz unlike cars ,Vibe's trunk is a continuity of the interior so the noise isnt that insulated?? I was just wondering abt that .Also i have 2 big cardboard boxes in the rear to put in grocery stuff .Could it be due to that??

[binary]

I had my entire trunk taken apart to run my XM antenna. And the trunk floor is both thin and uninsulated. I think the spare tire assembly actually stiffens the sheet metal. I noticed I can hear rocks bounce off the bottom of the trunk floor when I hit gravel or that gawd awful peagravel/tar cocktail they use to patch and fill our city roads now. I think I may be lining the bottom with some automotive undercoating.The open-ness of the back can lead to hearing much more road than we're used to. Having a cargo mat has helped and keeping the seats up-right and stereo up loud helps

[Boredstiff]

I had a similar situation which turned out to be nothing more than the rear seatbelt buckles smacking against the hard plastic sections to the left and right of the rear seating. Just what was the culprit in my situation yours could be something completely different just thought I'd drop this note in case it may aid someone.Regards,Boredstiff

[gargoyle]

Quote, originally posted by binary »...and keeping the seats up-right and stereo up loud helps I've found that technique helpful too!

[dennisdrive]

Yes that could be the noise ;i will have to look it up .In the front though i noticed that when the passenger seat belt buckle isnt properly retracted it does make a bit of rattling noise by hitting against the pillar .Might be the same for the rear ones too . And of course it could also be as you wrote --the vast emptiness of the space behind could be one of the reasons for the noise to echo.I am thinking of a mat for the cargo area .Will get one from Home depot and modify it one of the weeeknds when i am free .