Exhaust leak - ZR-1 Net Registry Forums

1990 quasar blue · 04-19-2008

I finally have the headers on, the RT cats and exhaust welded up, and am ready to head back to the dyno. When the car idles, I hear a very faint tick. To me it sounds like a slight exhaust leak but, the flanges and all the joints look clean. The exhaust guy said if it's making a ticking sound, then it has to be a header flange. My questions are 1. Is the exhaust guy correct? Or could it be a flange at the cats? 2. What's the best way to find a small leak? (I've read of some guys using Sea foam) and 3. Will this screw with my A/FR's or any other dyno data? I've tried tightening the header bolts that I can get to from the top and they are tight. Any help would be appreciated.
TIA,
Mike

32valvZ · 04-20-2008

I would say that the leak could be at the collector (s) OR the flange on one of the heads. Drive it for a while & then look for a black trail of condensation & carbon at the suspected attatching points. When its cold is probably when it will be most pronounced.

1990 quasar blue · 04-23-2008

Thanks, you're right. I only hear it when it's cold and even then you really have to listen for it. Unfortunately, all the joints are still spotless.

04-19-2008	#1
1990 quasar blue Join Date: Feb 2004 Location: Ma Posts: 404	Exhaust leak I finally have the headers on, the RT cats and exhaust welded up, and am ready to head back to the dyno. When the car idles, I hear a very faint tick. To me it sounds like a slight exhaust leak but, the flanges and all the joints look clean. The exhaust guy said if it's making a ticking sound, then it has to be a header flange. My questions are 1. Is the exhaust guy correct? Or could it be a flange at the cats? 2. What's the best way to find a small leak? (I've read of some guys using Sea foam) and 3. Will this screw with my A/FR's or any other dyno data? I've tried tightening the header bolts that I can get to from the top and they are tight. Any help would be appreciated. TIA, Mike __________________ 1990 ZR1 #2574 Medium Quasar Blue Metallic 1 of 19

04-20-2008	#2
32valvZ Join Date: Nov 2007 Location: Sunshine State Posts: 1,071	Re: Exhaust leak I would say that the leak could be at the collector (s) OR the flange on one of the heads. Drive it for a while & then look for a black trail of condensation & carbon at the suspected attatching points. When its cold is probably when it will be most pronounced. __________________ [B]1990 #2815[/B] [COLOR="Red"][B]Red/Red[/B][/COLOR] Ported Plenum & IH (by Pete) Haibeck Chip Rebuilt FPR (by Phil) FIC Injectors Watson LT Headers 3" Stainless Works exhaust Lingenfelter Open Air Lid Bill B Built Transmission Shifter & C Beam Plates [FONT=Impact][COLOR=red]1992 [COLOR=black]#[/COLOR] 091[/COLOR][/FONT] [FONT=Impact][COLOR=#ff0000]Red/[COLOR=silver]Gray[/COLOR][/COLOR][/FONT] [B]SOLD[/B]

04-23-2008	#3
1990 quasar blue Join Date: Feb 2004 Location: Ma Posts: 404	Re: Exhaust leak Thanks, you're right. I only hear it when it's cold and even then you really have to listen for it. Unfortunately, all the joints are still spotless. __________________ 1990 ZR1 #2574 Medium Quasar Blue Metallic 1 of 19