More engine noise, Mini Muffler Sounds in the Engine Bay. Options

[Spider77]

Ok, so I recently changed my plugs and wires. Cleaned what I could on the Intake manifold and the TB, as well as re-oiled my air filter. I was having a real rough idle after I did the InManifold and TB, but the plugs and wires kinda fixed that. But I still had excessive vibration at idle, but none during acceleration. Two days ago I run this road and pushed it kinda hard (I was having some fun), the next day I go to start up and everything seems fine, vibrations at idle almost all but ceased. When I pressed the pedal I got what sounds like I have a mini muffler up in my engine bay. Dont get me wrong, it sounds kinda cool just crusing under 2K (anything above that, it sounds normal). As I have never had this problem before, figured someone here might be able to figure this out.
Thanks!

[xrav22]

Ok, so I recently changed my plugs and wires. Cleaned what I could on the Intake manifold and the TB, as well as re-oiled my air filter. I was having a real rough idle after I did the InManifold and TB, but the plugs and wires kinda fixed that. But I still had excessive vibration at idle, but none during acceleration. Two days ago I run this road and pushed it kinda hard (I was having some fun), the next day I go to start up and everything seems fine, vibrations at idle almost all but ceased. When I pressed the pedal I got what sounds like I have a mini muffler up in my engine bay. Dont get me wrong, it sounds kinda cool just crusing under 2K (anything above that, it sounds normal). As I have never had this problem before, figured someone here might be able to figure this out.
Thanks!

I have one it is some sort of vacume pump it seems to run when I am idle with ac on

This post has been edited by xrav22: Apr 6, 2009 - 12:32 AM

[Spider77]

Yeah, Im gonna go out and look at it today to see if I have any vac leaks. But the problem dosent change if the a/c is off or on.

[Akirad1]

maybe a leak in your exhaust sytem hopefully not

[Ryouxrs]

can u post up a vid. clip of the noise? that'll help with diagnosis.

[Spider77]

I was thinking exhaust...hopefully if it is its just a gasket. Um, lemme me go out and get a vid clip for you guys.

[Akirad1]

aight man if you need any help when you get it figured out let me know

[Spider77]

Ok, so I had one that was in the engine bay, but due to the wind, fan and other noise (not to mention the crappy mic) I didnt really work out. But you can really hear it between 1K-2K. I also checked for vac leaks as I figured that might be a problem, well, dont have any of those. But when I sprayed the hell outta my T/B and connecting components, the idle smoothed out. So im gonna guess thats where part of my problem is, but it still has the throaty sound.

[Bitter]

sounds like a small exhaust leak.

with the engine cold plug the exhaust and disable fuel/spark, spray the manifold and gasket areas down with soapy water and crank the engine a few times. it'll bubble where its leaking.

[Spider77]

As in cram my tailpipe with a snake? Ok got that, besides pulling lines, what would be the easiest way to disable fuel/spark. Thanks

[Ryouxrs]

remove the fuel pump relay, and unplug the 2 distributor connectors

what did u spray your t/b with? and if the idle changed, recheck to make sure it does it everytime. if id does, replace the related gasket.

This post has been edited by Ryouxrs: Apr 5, 2009 - 5:16 PM

[Spider77]

Yeah, did that. Stripped off the heat shield and sprayed. Couldnt find anything yet. I'll try tomorrow under the car and see what I get. I sprayed the TB with carb/TB Cleaner. Im not sure if the idle changed per say, as I wasnt spraying and reading at the same time, but it seemed to smooth it out....not as rough. I dont want to strip down the TB again, but there is a new gasket on it. As far as an exhaust leak goes.....Ive usually seen smoke (not mine, but other peoples), and smelled exhaust. Thing is I have neither.
Im going to do some other checks tomorrow as well and see what i come up with.

[Ryouxrs]

just double check the intake manifold with carb cleaner again, and yeah, check the entire exhaust, if u see any bleck ash, or sooty looking deposits on the pipe spray it there with soap and try it, especially check any gasket surfaces.

[Spider77]

Well havent seen any ash yet. I was hoping to see some buildup on the back of my heat shield, but its still all shiny from when I cleaned it last time.

[Galcobar]

Check that your air filter box is properly locked down, having it slightly off produces a surprising amount of noise; sort of replicates the SRI sound.

[Spider77]

No box, Injen.

[Ryouxrs]

any updates on the noise?

[Spider77]

Not yet, yesterday was too cold, and spent most the day at dr office for the kid. gonna try to go out today.

[Spider77]

Ok, so its totally the flex pipe....Im surprised that its even making an attempt to stay on. Almost all of the flange connecting it is rotted away, so now it just kinda sits there. Thanks guys for the help. Now I have one more question. What size is the stock flex pipe? Any guesses?

[Ryouxrs]

no idea, u could take it to a local exhaust shop, and have them look at it, and or replace it

[Spider77]

Yeah, Im going in in about a week or so to get my exhaust put on. Thanks

[Spider77]

OK, so its been a while since Ive worked on the celi. Still having rough idle problems I decided to strip down the TB again. This time I really went all out, after I cleaned the TB, I sprayed TB cleaner all over the place. Then took off the vac lines and blew compressed air through it, also removed the thing that runs in series with the MAP sensor to the EGR (not sure what the things called, but its screwed into the intake), cleaned that. Couldnt remove the IAC though, its kinda stuck in there. Long story short, everything works great. My question would be this. There should be no problem with sprayin carb cleaner into the TB while the car was running? I kinda did that for a bit, figuring that it might help clean the intake...but there should be no adverse effects?

[Ryouxrs]

not unless u hit a sensor with it, its just very cumbustable, and not sensor safe, intake cleaner would have been a better choice, but if it runs good i dought u hurt anything