Apparent Exhaust Leak and Gasket/Manifold Replacement Questions

[runningonfords]

The other day I noticed a ticking sound that was changing with engine speed and really apparent when accelerating while driving with the windows up. Further examining at home seems to indicate the sound coming from the front (radiator) side of the engine. It sounds like I'm hearing the firing of the engine, not toooo loud though, goes faster when the engine goes faster. Does not always make the sound at idle, but when you goose the accel you can hear it always. TICK TICK TICK TICK TICK. It seems to make the sound at idling when engine is cold. Nearest Dealer was "very busy" and after holding my car for days without a diagnose and estimate I said forget it and brought it home. I am pretty sure this is exhaust manifold/converter or gasket failure as the first technician I talked to had indicated. The only ODD thing about this problem is that I can't really smell any exhaust gases in the engine compartment, either above or below the vehicle. That makes me think I am diagnosing this wrong?!? Any reason why I wouldn't smell exhaust from an exhaust leak? Also, has anyone replaced the manifold/converter on the front (radiator) side of the engine? Are there other major parts that need to be moved/removed to complete manifold replacement if the manifold IS indeed cracked or warped? My only other inclination is to get a cheap stethoscope and try harder to find the noise, good idea? Also, if I pull the manifold off, how can I tell if the mating surface is warped? Thanks to all who respond

 

[Kikinz24]

I had to change the rear manifold on my wife's it was warped... Only had 7200 miles on it. I took it to the dealer under warranty they did not want to replace it stated the car had an accident on the Carfax no info just said accident reported and it was probably cracked . If they took it apart it was going to be $2100 out of my pocket.. I wasn't about to take that chance so I bought a new manifold and changed it out.. it was in fact warped not cracked at all.. at the far right side. The head is tapped for a bolt there but the manifolds do not have a bolt hole in the corner... ( Bad design). Anyhow I took the manifold back in and they wouldn't repay the parts cost .. it wasn't hard to do.. and the front would actually be easier.. 2 bolts on th exhaust pipe take the shield off and take the manifold bolts out lift it out the top.

 

[Mbrooks420]

I had to change the rear manifold on my wife's it was warped... Only had 7200 miles on it. I took it to the dealer under warranty they did not want to replace it stated the car had an accident on the Carfax no info just said accident reported and it was probably cracked . If they took it apart it was going to be $2100 out of my pocket.. I wasn't about to take that chance so I bought a new manifold and changed it out.. it was in fact warped not cracked at all.. at the far right side. The head is tapped for a bolt there but the manifolds do not have a bolt hole in the corner... ( Bad design). Anyhow I took the manifold back in and they wouldn't repay the parts cost .. it wasn't hard to do.. and the front would actually be easier.. 2 bolts on th exhaust pipe take the shield off and take the manifold bolts out lift it out the top.

Was it in an accident?

 

[Kikinz24]

Was it in an accident?

It was but not enough damage to hurt the engine in any way... I didn't want to take the chance tho for $2100!!! Carfax is helpful in some ways but in other ways can screw a car owner over.. I've seen so many minor accidents /swipes get reported then trade in value goes down big time.. but yet some accidents don't even get reported and hacks put them back together and sell with a "clean" Carfax.. that was when I realized the dealer will do ANYTHING to get out of fixing something at no cost

 

[Mbrooks420]

If it were cracked from the accident, I would have said that’s the insurance companies deal. Otherwise, it’d be a warranty item.

I don’t think Carfax really screws anyone. The car WAS In an accident, so it’s value should be less than a non-accident vehicle.

 

[runningonfords]

Thank you for reading and replying. I was mostly looking for proof that someone, somewhere bought these parts and did it themselves. And to know that someone might reply when I'm stuck halfway through the job LOL. I take back what I said about the smell. I tested a cold engine and used another witness and you can DEFINITELY smell exhaust up there. I also used a mechanics stethoscope and a mirror and light with the heat shield off, but can't pinpoint the actual site of leak, perhaps soap bubbles necessary here. I definitely did NOT HEAR any mechanical noise that matched the TICKING with the scope on the engine block up or down side or any of the exhaust parts. You CAN definitely tell that the front part of the engine, not the back, is where its coming from. Anyway, I bought the parts : 1 manifold/catalyst, 6 studs, 6 nuts, 2 different gaskets, 2 y-pipe nuts. My new questions are did you pull and replace all the studs as well? What is the torque value for the 2 oxygen sensors? Is the dealer correct in saying there is no torque sequence for the manifold, just torque to 17 ftlbs then torque all over again to 25 ftlbs? AND, can you get the new mani in on the y-pipe without disconnecting it from the other cat converter in the rear? Seems as you said, drop in from above is the way to go here. I feel like I'm going to use a lot of PB Blaster for this job. Thanks so much again for reading and replying.

I had to change the rear manifold on my wife's it was warped... Only had 7200 miles on it. I took it to the dealer under warranty they did not want to replace it stated the car had an accident on the Carfax no info just said accident reported and it was probably cracked . If they took it apart it was going to be $2100 out of my pocket.. I wasn't about to take that chance so I bought a new manifold and changed it out.. it was in fact warped not cracked at all.. at the far right side. The head is tapped for a bolt there but the manifolds do not have a bolt hole in the corner... ( Bad design). Anyhow I took the manifold back in and they wouldn't repay the parts cost .. it wasn't hard to do.. and the front would actually be easier.. 2 bolts on th exhaust pipe take the shield off and take the manifold bolts out lift it out the top.

 

[runningonfords]

Finished installing new manifold/cat on the radiator (front) side of the engine a bit ago. It was fairly easy. All 6 studs came out when turning the nuts off. Mani/Cat comes out the bottom after undoing the y pipe from the rear side also and it flexes down/out of the way. You only need 1 y pipe gasket (oval shape) as the rear one is more a flanged than a gasketed fitting. I bottomed out the oxygen sensors with a 7/8 combo wrench in my lap. When putting it back, hand start all the studs and like any mating surface, be careful that everything is super clean all the way around. Also, the exhaust y-pipe stud can be stuck and twist off leaving you with no stud to screw back onto on either mani/cat. Nickson clamp-a-stud C-shaped is the product that saved me at the end here. Just as well, having lots of different extension sizes and shapes are your friend here as its crowded near the cat. Buttoned it all up and we're rolling steady these days. Problem solved.