4.0 exhaust leak

[4.0 power]

while changing the oil the other day, i noticed this weird noise coming from the left bank of the motor while running. i have a full borla exhaust (headers to tailpipe) and its still in good shape so i find it hard to believe it could be a failed weld, etc. Cant say power is down, but fuel mileage has taken a huge dump this tank though which raised my eyebrow.

didnt notice any discoloration on the header either.

my question, to those who have a borla exhaust, have you experienced a failure of that type?

next question, what sound does a bad header gasket make? or what should i look for?

 

[AllanD]

My borla headers are on the floor under my workbench.

why? because one of the tubes cracked along wht wekd to the collector.

After taking them off I found other cracks, now there's nothing I can't get welded, but rewelded headers often crack again and I didn't want to be dealing with that in December/January/February, so I put cast manifolds back on it.

I'll deal with it later.

But don't believe that your Borla's can't crack,
I can absolutely assure you that they most definatly can!

AD