It seems to alternate between the resonator, the cat... it's hard to pin point the exact location... it's intermittent too... I suppose it could be leaking at one of the welds if it's even a leak... I wonder if there's a connection to the vibration as well.
So I have the DC Header with an extended flex pipe and custom dual magnaflow exhaust w/ 18" resonator on my '05 i4 coupe. Recently I started noticing a "ticking" sound when the car is running. The ticking persists after the car is shut off (which seems common on many cars, the result of the pipes cooling down)... but I can literally hear this when I pull up against anything solid (a drive thru for example. If I had to compare the sound to something, it would be like tapping a knife or something against a metal pipe. It occurs every 5 - 10 seconds, and gradually slows when the car is turned off. In addition to this, I'll feel a somewhat strong vibration coming from the rear of the vehicle when stopped at lights, which will go away if the car is put in neutral. Any suggestions as to what might cause this? Please let me know if there's anything else you need to know. Thanks.
can someone tell me if the bolts on the head of the engine holding the exhaust manifold on snap easily? how can i prevent them from stripping or snapping
Mine broke without too much muscle, no pb blaster, but I realized after the project that two nuts were basically locked on their bolds, so they came off like the rest of the bolts. If you're pulling with all your might, you'll probably strip something, so just use your best judgment.
Slightly off topic, but regarding noise from the header.. I've had my flex pipe swapped out already, which made it somewhat quieter, but the thing is still loud, it's especially noticeable when driving next to concrete dividers, or walls... and don't even get me started about the noise when driving through a tunnel. I wasn't expecting it to sound dead quiet, but how loud is too loud? I'm not sure what the threshold is for normal. My only other guess is that those crush rings on the down pipe are screwed, or the stock gasket I reused up top (I guess you would call that portion the A pipe?) is no good, or... perhaps dc headers are just kinda loud when driving next to large solid objects... Any ideas?
From what you've described, I'm guessing it's the flex pipe. You should go to an exhaust shop and have them find the leak and fix it.
Someone get that man a cigar....
Went to the shop today.. and it was indeed the flex. He made it a point to tell me I got the o2 sensor in there "real good.." lol.. Car sounds much better. Thank you guys!
We do meets during the morning/day you can be back spinning records don't worry lolz... make a profile HERE so we can see your ride! Good luck with your fix man...
Done, and thanks man. I'll report back when everything is fixed and let you know what it was..
OK... well asfar as the rethreading is concerned they sell a tool set and you can do it yourself OR the shop can do it for you! You could possibly have a leak if your still get smoke swirls around the flex pipe. Take it to the shop and have them check it out for you...
OFF TOPIC for a sec....
Where in NYC you from...? Chime in on the NYCM squad thread HERE plus there is a bbq meet up in CT you can check out HERE
Hope to see you at some meets dude! Get to know your fellow members...
Yeah, I plan on taking it to a shop next week. The good news is, when calling around for estimates, I was referred to this small custom exhaust shop by a regular garage (which I've been looking for for a while, they don't exactly advertise in the yellow pages).. and he has a mandrel bending machine (which noone else around here seems to have), so when I do my exhaust, I'll probably go back to him, provided he does good work and gives me a fair deal.
**** Question.. to rethread the hole for the o2 sensor.. Do they have to take off the downpipe? I suppose it doesn't matter. If it needs to be fixed, it needs to be fixed. So sick of spending money on this damn install.
As far as NYC goes, I used to live on 34th and 9th in Manhattan for nearly a decade.. then moved back to LI to finish school. I still DJ in the city Thurs - Fri - Sat. Would love to come hang out, but I work Saturday's man.. gotta be spinning by 10.
Hard to see if it is cracked... you might have stripped the threads taking out the old 02 sensor, I know I did when I changed out mine. I had to rethread it and the o2 sensor sat fine. No problems since. Btw your flex pipe is clean as hell...
That's definitely a possibility. I screwed the new one in already, and it sits flush, and still "turned" while screwing it in, but it took a good amount of effort getting it all the way down. I can't rule out that the threads on the header aren't stripped, I just know it has to be stupid tight for it to not fall out. I thought it was tight the first time and it fell out on me. When I re-screwed the broken sensor in, I made sure it was in good. Same today when I replaced it with a new one. I figure my best bet is to take it to an exhaust shop now and see what they say because there's definitely a leak somewhere. Again, I noticed grey smoke swirling around the flex pipe area like the flex pipe itself was haunted immediately after the car was turned on, it stopped about 2 minutes later. The hot air I felt was flowing from right the area around the o2 sensor, so I'm trying to figure out if the o2 sensor hole there has a leak, or it's the weld next to it.
I'm reluctant to think it's the flex, because it DID NOT sound like this (which was later diagnosed to be a cracked flex pipe):
OK, so here's the latest. Got the o2 sensor in the mail yesterday, and I installed it today. Disconnected and reconnect the battery, and that cleared the CEL, HOWEVER, I crawled under the car and put my hand around the o2 sensor area (tight as hell w/ vice grips) I felt hot air blowing. The weld directly next to the o2 sensor looked a little shady, like there was what appeared to be the smallest of cracks in there. I've attached a pic (best I could get with my phone) to show you what I'm talking about. Check out the weld directly to the right of the o2 sensor:
Also, when I first started the car you could see smoke flowing around the flex pipe area. It's one of three things I think. The o2 sensor threads got stripped, so it's just not sitting tight, the weld in the photo is forked, and I need to take it in to have it patched, or the flex is shot. As always, your help is appreciated guys.
After you replace that, give it another try and see if you still have the noise. It could be a cracked flex pipe also. That's what I'm dealing with right now. I'm having to get mine replaced a 2nd time.
Thanks Tim.. In the meantime, what are the obvious symptoms of a cracked flex pipe? When I did the install, I did notice the slightest little rip in the end of the FP (obviously, CAT side), amounting to no more than a millimeter in length, so I figured it was fine.. I wish I could record the sound of this to give you guys a better idea of what's going on.. and perhaps some better diagnostics.. There's a chance I didn't torque the cat bolts correctly as I just did it by feel.. it's hard to imagine what else could be going on here...
You're first task is to try and determine if the noise is coming from near the engine or near the tail pipe, then we can move on to phase 2.
It's definitely closer to the engine, tail pipe doesn't make much noise at all actually. When I crouched down and took a look while the car was being revved, the cat itself seemed to have a good bit of "movement" to it. Dunno if that's normal or not. My new o2 sensor is going to be here Monday or Tuesday, so that will help eliminate that problem..
From the description, it sounds like a bad leak from one of the junctions and not the flex pipe. You might have a blown gasket or that o2 sensor isn't plugging up the hole very well. If you were to lay down next to your car and listen for it, it'd help you and us determine what the problem is. Another question I have is if there are any mods to the stock exhaust (I.e. removed resonator) or is it unmolested?
Do you have anything plugging the hole for the primary a/f sensor on your header right now?
yes, the broken one, so it doesn't sound like a ride-on lawn mower (there's no mistaking the sound when that thing pops out). now it only sounds like one of those push mowers.
Show Posts
