I recently hit a dip that did in my downpipe. I had a new downpipe made that was about 3.5" higher, so I don't have any clearance issues, but now I still get a whiff of exhaust from time to time, and especially when the car is still cold and I jump on it. I have a cast mani, and I figure it must be a crack, although none are visible. Is there any way to try and locate the crack so I can fix it until I can get another mani?

 

start your car & let it Idle.

get a piece of hose or something and use it as a stethascope.

If exhaust gases are coming out you will be able to pinpoint the crack by listening to it.

 

Try soap and water in spray bottle and see where it bubbles. Im not sure if the heat will make it all bubble but cant hurt to try.

 

Get one of those drug sniffing dogs, like they have at customs.


Or, light up your crack pipe and blow the smoke in the general area of the suspected leak (making sure other sources of air have been isolated) Watch the smoke, it will be blown away from the area of the leak.

BTW, stop smoking crack and dealing it to our kids

 

You can usually find soot trails when you have a crack.

 

water wont work, it will steam and evaporate, soot is good idea, u can try to feel the pulse of air...but its hot

 

If you spray the manifold with soapy water and then turn on the car the manifold won't be hot enough to evaporate the water, so you'll have a few seconds to find the leak, or have a friend find it.

 

NDT

non-destructive test spray.

pick it up at your local welding supply store. 3 spray cans: cleaner, fixative, and developer. if there is a hairline crack, it will dye it red.

although... i would think that if the crack were large enough to start leaking exhaust, you'd be able to see it, and you would see carbon trails.

also, since the damage to your downpipe was so severe, as to make you worry about the manifold, i would be worried about the exhaust housing, as well.


and:
if you only get the whiff of exhaust smell when your car is still cold, then maybe your cat just hasn't had time to pre-heat.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dee &raquo;</TD></TR><TR><TD CLASS="quote">You can usually find soot trails when you have a crack.</TD></TR></TABLE>