What do you guys think is happening with this Fiesta?

[uncleAl]

I am new to the forums here and have been wanting to buy a Fiesta ST for a while and may have found a good deal. Problem is, it's misfiring.

Oil looks good, has Cobb stage 3 tune, 112k miles, 2014, oil changed every 5k miles. Included a Youtube video link of it. Everything is pointing to a possible exhaust leak - when revved, it smells like exhaust in the engine bay. Not sure if this is a normal misfire sound on these. Any opinions would be great!

View: https://youtu.be/C3B0y38TGb0

 

[madhatter]

i'd wager it's a cracked exhaust manifold. Possibly cracked downpipe or a bad exhaust gasket, but i doubt it is a bad gasket.

that's definitely not a normal sound.

 

[Stupidbutt]

is the symposer still there or loose?

 

[Dialcaliper]

That definitely sounds like an exhaust leak, probably at the manifold as mentioned above and not a “misfire” to me. Engine is probably still firing fine on all 4 cylinders as the deeper sound coming out of the exhaust pipe sounds pretty normal

Get about 3ft of garden hose (preferably the black rubber kind that won’t melt as easily) and use it as a stethoscope to probe around the exhaust manifold and downpipe area which can help pinpoint the location of the leak.

 

[uncleAl]

i'd wager it's a cracked exhaust manifold. Possibly cracked downpipe or a bad exhaust gasket, but i doubt it is a bad gasket.

that's definitely not a normal sound.

I think you may be right. I am looking into all options commented on here! Thank you for the input.

 

[uncleAl]

is the symposer still there or loose?
View attachment 64148

I ended up trailering it home yesterday. Going to check this shortly!

 

[uncleAl]

That definitely sounds like an exhaust leak, probably at the manifold as mentioned above and not a “misfire” to me. Engine is probably still firing fine on all 4 cylinders as the deeper sound coming out of the exhaust pipe sounds pretty normal

Get about 3ft of garden hose (preferably the black rubber kind that won’t melt as easily) and use it as a stethoscope to probe around the exhaust manifold and downpipe area which can help pinpoint the location of the leak.

I will certainly try this. I ended up trailering it home so I will be diving in today. Appreciate the input!