rattling from under car

for the first 5 minutes or so after I start my 98 Civic, there is a vibrating noise coming from under the front of my car. In previous cars, the culprit has been the head shield which I have easily removed. The
shield for this car is long gone so it can't be that. The noise seems to go away after about 5 minutes.
Any ideas what it could be? My guess is that something with the exhaust system is loose.
Thanks
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MG wrote:

Bad engine mounts, or possibly even loose A/C lines that are vibrating.
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MG wrote:

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Exhaust system 'grows' by about an inch as it gets hot. Shake it when it's cold and see what's loose / touching what.
'Curly'
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MG wrote:

There's also a heat shield over the cat converter. It has a couple of tabs that tend to rust out. Get an automotive stethoscope (sears) and probe around. Noises can be tricky to find as it travels.
Remco
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MG wrote:

exhaust manifold crack?
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is this something that gets replaced if I get a new exhaust system? The car is 8 yrs old with the original system on it.

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You have approximately eight hundred heat-shields on your exhaust.
If you get each entire part replaced at the dealer, they will come with new shields. Usually.
There are a number of shields that are attached to parts that are excruciatingly expensive to replace (the cat, for instance). In those cases, you're best to either get them torn off, or spend the $50 or so for each shield to replace them. Sometimes a hose clamp can be tightened on to the shields to stop them rattling.
If you get Midas or Speedy to do the work, you will get no new shields at all, and will be back the very next spring to get more welding done. In the end, it will cost you more than dealer replacements.
--
TeGGeR

The Unofficial Honda/Acura FAQ
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Check with your Honda Dealer, there's some kind of special warranty for exhaust manifold cracked (within those years 97-99?)

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