|
|
Register To Post |
| JeffK | What sounds like exhaust leak but isn't? | ||
|
Elite Guru
 
|
Took it to a shop today to see if they could fix my exhaust leak. I swore it was leaking at the cat / y pipe connection.
The guy can to the waiting area and asked me to come show him what I was hearing. He had it up on the lift running. The noise wasn't coming from the connection I thought it was nor was it coming from the header collectors. It honestly sounds like it's coming either from the bottom end or the headers themselves. The sound that I hear is a ticking which speeds up with throttle. It drives me nuts, when I go through a drive through it echos off the walls or when I'm at a light next to a car it echos off the cars around me. Is it possible that the Bosch injectors are that loud and the clamshell directs the noise down when it's closed? could it just be the headers, do they tend to increase the under hood noise levels? Here is a video of the top end after I had the heads freshened w/ LT4 springs, 1.6 roller rockers, hardened p-rods and guides. I know some of you have seen this already but... Anyway, this ticking noise is driving me crazy.     I might try Joe's suggestion of putting a washer under the fuel rail to see if it quiets the injectors down and gets rid of this ticking! |
||
Posted on: 2011/3/14 18:41
|
|||
 Transfer
|
 
|
||
| biggrizzly | Re: What sounds like exhaust leak but isn't? | ||
|
2011 Memorial Day Car Show Winner!
 
|
Sounds like valve train and injectors to me. Its hard to really tell from a video though.
|
||
Posted on: 2011/3/14 20:09
|
|||
|
_________________
Don Haller Corvette Club of America 94Coupe, 383Stroka, PeteK Trans, 3000stall, 3.54rear, Konis and bigger sways. |
|||
|
Transfer
|
|
||
| NelsonV | Re: What sounds like exhaust leak but isn't? | ||
|
Senior Guru
 
|
I can't tell from the video... but a loose spark plug maybe?
|
||
Posted on: 2011/3/14 20:13
|
|||
|
_________________
One GOD, one nation, eight cylinders. |
|||
|
Transfer
|
|
||
| JeffK | Re: What sounds like exhaust leak but isn't? | ||
|
Elite Guru
|
It seems to have a totally different sound underneath. The top end is all injector noise that much I know. Maybe I should send Jon the video and see if they are supposed to be that noisy.
|
||
Posted on: 2011/3/14 20:26
|
|||
|
Transfer
|
|
||
| bogus | Re: What sounds like exhaust leak but isn't? | ||
|
Grand Imperial Pooh-Bah
 
|
I am having a tough time hearing the tick...
The old trick - take a long screwdriver and star putting it on bits of the car that might make that noise - rocker covers, injectors, etc. And use that to track the noise back. |
||
Posted on: 2011/3/14 20:37
|
|||
|
_________________
The single biggest problem with communication is the illusion that it has taken place. - George Bernard Shaw Education is the best tool to overcome irrational fear. - me |
|||
|
Transfer
|
|
||
| JeffK | Re: What sounds like exhaust leak but isn't? | ||
|
Elite Guru
|
I tried the mech stethoscope and it does not seem to be coming the top end unless it's injectors. I might have to get it up on stands again and run it. When I was at the shop under the car today it really sounded like it was either in the oil pan or the headers. I know that it can resonate though...
|
||
Posted on: 2011/3/14 20:42
|
|||
|
Transfer
|
|
||
| JeffK | Re: What sounds like exhaust leak but isn't? | ||
|
Elite Guru
|
Quick vid under the car...
ok, having trouble linking the video... http://www.youtube.com/watch?v=CdSBsinswhw |
||
Posted on: 2011/3/14 21:46
|
|||
|
Transfer
|
|
||
| flyboy | Re: What sounds like exhaust leak but isn't? | ||
|
Elite Guru
|
Exhaust manifold gasket leak? But that usually goes away at idle, I think.
|
||
Posted on: 2011/3/14 22:48
|
|||
|
_________________
'91coupe, LT4Hotcam, some other stuff. If it's too loud, you're too old. "He works on old cars, then junks 'em" |
|||
|
Transfer
|
|
||
| Matatk | Re: What sounds like exhaust leak but isn't? | ||
|
Webmaster
 
|
I'm having a hard time detecting an exhaust leak. Sounds like valve train noise. Some rockers are more noisy than others, might be what you're experiencing.
Matthew |
||
Posted on: 2011/3/14 23:13
|
|||
|
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
|||
|
Transfer
|
|
||
| JeffK | Re: What sounds like exhaust leak but isn't? | ||
|
Elite Guru
|
Honestly, it was there before I did all of this. I always thought it was an exhaust leak..haha. We all know what happens when you ass-u-me
|
||
Posted on: 2011/3/14 23:18
|
|||
|
Transfer
|
|
||
| Matatk | Re: What sounds like exhaust leak but isn't? | ||
|
Webmaster
|
Quote:
Then tell your wife my diagnosis is a broke geigenflutter valve in the motor and you need a 383 to repair it  |
||
Posted on: 2011/3/14 23:55
|
|||
|
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
|||
|
Transfer
|
|
||
| JeffK | Re: What sounds like exhaust leak but isn't? | ||
|
Elite Guru
|
Quote:
If only my wallet would support that.  Couldn't really mess with it last night since I had class but I was thinking about this issue last night. It all started after the first time I changed the plugs. I thought that getting the heads freshened up and having him check the plug threads would make it go away. I even found an old thread on CF that I posted when this all started. I couldn't remember what I did first, the injectors or the plugs. Seems I did them all at the same time. Maybe it is the injectors that are making the noise I hear.. http://forums.corvetteforum.com/c4-te ... e-cause-exhaust-leak.html |
||
Posted on: 2011/3/15 11:48
|
|||
|
Transfer
|
|
||
| Ultraman | Re: What sounds like exhaust leak but isn't? | ||
|
2015 Memorial Day Car Show Winner!
|
Jeff this is really off the wall but I had it happen to me. It started with the ticking noise that I noticed when I was waiting in line at Burger King. I could not find the problem. As the engine raced up the ticking would get worse and settle down with the rpms. Drove me nuts.
I could not find it but then other weird noises started which I would have a hard time explaining but whistling ehaust leak might get close. I used the old screwdriver stethescope and located what I thought was the source which was the air pump. I wanted to delete anyway, so I did. Didn't solve anything. Turns out I was close. It was the bearings in the alternator that were bad or something in there that was making all the noises. New alternator and all better. I realize this is reaching but thought I would share. |
||
Posted on: 2011/3/15 13:26
|
|||
|
_________________
2010 Grand Sport Coupe Gone but not forgotten... Vote DeSantis in 2024.... Make the IRS go away... |
|||
|
Transfer
|
|
||
| JeffK | Re: What sounds like exhaust leak but isn't? | ||
|
Elite Guru
|
Quote:
That's very interesting, I would have never thought to look at either of those components. I will check them out tonight. Alternator looks pretty new but I will take my length of hose to it. Thank you |
||
Posted on: 2011/3/15 13:30
|
|||
|
Transfer
|
|
||
| CentralCoaster | Re: What sounds like exhaust leak but isn't? | ||
|
Senior Guru
 
|
Start the car without the serpentine belt and see if it goes away.
Don't run it too long though! |
||
Posted on: 2011/3/15 20:14
|
|||
|
_________________
1985 Z51, ZF6 |
|||
|
Transfer
|
|
||
| JeffK | Re: What sounds like exhaust leak but isn't? | ||
|
Elite Guru
|
I give up. I'm just going to call it the Corvette tick and drive on.
It's not the air pump or the alt. Thank you for the suggestion! It seems to be coming from #8 plug, the header collectors (where the 4 pipes meet), the oil pan, left front wheel...well, you probably get the point by now. I seriously think it is the injectors and it's just reverberating all over the place. I pulled #8 plug and did a compression test just to see. It has 180 psi. The plug was a little carbon fouled which I thought a little odd since it's only got 50 miles on those plugs. I put the plug back in and ran it without the wire, still ticking. I emailed Jon @ FIC a link to the video of the top end to see if he thought the injectors were overly noisy. We will see what he says. |
||
Posted on: 2011/3/16 1:11
|
|||
|
Transfer
|
|
||
| Churchkey | Re: What sounds like exhaust leak but isn't? | ||
|
Guru
 
|
Suggestions:
Check the water pump pulley bolts & the balancer pulley bolts + the balancer to crank bolt. Auto trans? Check for a crack in the flexplate. They normally crack near the crank hub, you should see a line of rust @ the crack. The loose pulley(s) & cracked flexplate will cause a knocking noise. If the above checks ok: Engine @ idle pull one plug wire at a time from the distributer. You may be able to isolate the noise to a particular cylinder. EDIT: Just reread your first post, the heads were "freshened"? Was this done on the car? You may have a worn valve guide which will also cause a ticking noise. Luck with your search. |
||
Posted on: 2011/3/16 13:18
|
|||
|
Transfer
|
|
||
| JeffK | Re: What sounds like exhaust leak but isn't? | ||
|
Elite Guru
|
Heads had new valve seals, new LT4 springs and keepers, bowls cleaned up and #8 plug hole heli-coiled.
All done off the car by a local machine shop that came highly recommended by hot-rodders and SCCA drivers that I know. |
||
Posted on: 2011/3/16 13:35
|
|||
|
Transfer
|
|
||
| Matatk | Re: What sounds like exhaust leak but isn't? | ||
|
Webmaster
|
Just drive it over to my house, Jeff, and I'll take a look
|
||
Posted on: 2011/3/16 13:37
|
|||
|
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
|||
|
Transfer
|
|
||
| JeffK | Re: What sounds like exhaust leak but isn't? | ||
|
Elite Guru
|
Aren't you still buried in snow?
If you were in TN or even GA I would be there this weekend. Chicago is a bit of a stretch. How about if I just buy you a plane ticket instead? lol |
||
Posted on: 2011/3/16 13:40
|
|||
|
Transfer
|
|
||
| jhammons01 | Re: What sounds like exhaust leak but isn't? | ||
|
Senior Guru
|
Have you pulled the valve covers??
|
||
Posted on: 2011/3/16 18:06
|
|||
|
Transfer
|
|
||
| Matatk | Re: What sounds like exhaust leak but isn't? | ||
|
Webmaster
|
Quote:
He did another thread where he documented his head gaskets, headers, roller rockers, etc. The noise was there before and after. Jeff - no snow, the vette will be fine on the way up here |
||
Posted on: 2011/3/16 19:02
|
|||
|
_________________
2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
|||
|
Transfer
|
|
||
| JeffK | Re: What sounds like exhaust leak but isn't? | ||
|
Elite Guru
|
Tried to go through the Burger King drive-thru today...had to go inside the guy couldn't hear me over the ticking. @!#%^@%#$@^&&!!!
It runs great though... |
||
Posted on: 2011/3/16 19:24
|
|||
|
Transfer
|
|
||
| MikeG | Re: What sounds like exhaust leak but isn't? | ||
|
Guru
|
Had a tick that evaded me forever, turned out to be the oil pump. Held great pressure but had a bad shaft bushing in the pump. Hope this isn't what you have.
|
||
Posted on: 2011/3/16 22:03
|
|||
|
Transfer
|
|
||
| JeffK | Re: What sounds like exhaust leak but isn't? | ||
|
Elite Guru
|
Wow, I hope that's not it!
|
||
Posted on: 2011/3/16 22:57
|
|||
|
Transfer
|
|
||
You can view topic.
You cannot start a new topic.
You cannot reply to posts.
You cannot edit your posts.
You cannot delete your posts.
You cannot add new polls.
You cannot vote in polls.
You cannot attach files to posts.
You cannot post without approval.
|
|