popping noise?

I have a 98 lgt wagon with 131,xxx mile on it. For about the last month or two I have been hearing this very quite popping noise when I let off the peddle, coast, and then get back on the gas. It kinda seems like a backfire but on the way quite side. The noise is really quite, a person riding with me would not hear it, I am just very nervous when I hear a noise that is new on my car. So my question is what is causing this? Its a stock exhaust for the most part. I had a new mid pipe put on because the old one rusted out. Is my car running richer thus causing this noise or do I maybe have a hole or crack in my exhaust and that is why i am hearing this? Thanks for the help.

my car makes a popping sound too when i let off the pedal to shift. It started happening after i got a catless DP on my LGT, and just got worst when i got a catback.

 

In for answers too.

sounds like driveline slack to me.

sounds like driveline slack to me.

 

 

Could you expand on this? I have also started, just as of today, to here a small light clunk when I hit a crack in the road. A big bump does nothing. No idea what this is or if it has anything to do with the popping.

 

I really do think that the noise is coming from the exhaust but I climbed under the car earlier and it all seems to be solid.

bbc84 it is prob your driveline hitting the downpipe I know alot of us have had this problem with the megan downpipe. Check this thread, http://legacygt.com/forums/showthread.php?t=92914

 

I don't know about the older gt's but it may be the same thing if the sound came the same time as the new exhaust. Just check all the heat shields and the mounting points and make sure you drive line isnt close, cause i thought mine couldn't hit it at first, but the shaft moves more then I thought when in reverse or throttle off under load. So, I bent it out out the way and now no noise. My $.02

Could you expand on this? I have also started, just as of today, to here a small light clunk when I hit a crack in the road. A big bump does nothing. No idea what this is or if it has anything to do with the popping.

 

I really do think that the noise is coming from the exhaust but I climbed under the car earlier and it all seems to be solid.

 

 

i could be wrong and probably am but...

 

 

when you have a load eveything is tightned up. let off and it all relaxes. get back on it and it will tighten back up again but do so with a "clunk" from everything setting back in place.

 

 

imagine a bell...the wind is blowing on that piece that dings around and it is stuck up against the side of the bell. wind stops and the dinger relaxes in the middle. wind picks back up and it hits the side of the bell to make it ring.

 

bad anology but should make the point.

So it isn't somewhere from the intake then? Some ventilation valve or something that makes a noise when the vacuum increases?

Thanks for all the input....I dont think that the popping is from the exhaust hitting anything....its just not that type of noise....its more like a super quite backfire being muffled. The small clunk seems to come from the front and the popping seems to come from right in the middle of the car to the back end of it. I can only get the noise when I am drive in sometimes second, third most often, and once is a while fourth. When the noise does happen the car is under very little load if any. Normaly coasting down a hill in gear and then getting back on the gas lightly will make it go pop pop pop....I wish I could record the sound but its way to quite.

Ya if it is doing it when you are on the throttle it probably isn't rubbing, mine happened in reverse or when i let off the throttle in low gears. Kinda the same noise though I thought mine was backfiring at first. Hope you can find the problem.

So it isn't somewhere from the intake then? Some ventilation valve or something that makes a noise when the vacuum increases?

 

 

dude i have no idea. really...just giving possibilities.

^^ ill look into that. I did take the air filter off a couple days ago and then had the hardest time getting it to go back on. Maybe that screwed something up, I dont know. Thanks for the help guys.

So I am almost positive that I have an exhaust leak. If I plug the tail pipe I can hear a whistling noise coming from somewhere under the car. Under the right driving conditions I can get the whistle to happen also. I think its coming from around the catalytic converters. Those are the only things that still have the heat shield on. Nothing looks visibly broken but I got to wait for my dad to get home to try to help me find the leak. I also can hear a small clunk or more of a clank when I hit a small crack in the road....trying to figure out what that is, I hope it has something to do with the exhaust instead of a different problem.

A cracked exhaust system then. May be tricky to find in some places, but check around welds and inside of bends.

 

It may also be a dead gasket.

^

That is what I am going to be doing today. The only places I cant tell are the ones behind the heat shield covering the catalytic converts. Ill have to pull those off and check it out.