[ranxerox]

There was a guy on facebook, A ambulance mechanic, Who did it without pulling the engine. He almost makes it look easy.
I think he dropped the subframe to make it easier, But later he said you could probably do it without dropping the subframe.

 

[Rigel]

Yikes! Too bad, good luck on the repair. What year, mileage and motor would be useful info. Thx

 

[RonR]

It's a 350,2017 3.5 EcoBoost with about 95,000 miles on it. Never been in the salt and fairly gently used. Inspection shows that all the studs are in roughly the same shape. It does seem like a problem that is bound to happen with any EcoBoost. A little surfing on the F150 site shows it is very common on the EcoBoost in that truck. There are some claimed improvements but there have been exhaust problems with those as well. Everyone who has reported doing the job has broken other studs. Most have dropped the entire engine. A serious repair.

 

[Kevo]

Sorry for your manifold troubles Ron. Good ambulance YouTube find ranxerox. Is it heat causing the manifold to distort and fail, or is it heat, water damage and steel bolts In aluminum? Perhaps cleaning and/or replacing with proper torque the bolts every 30k miles might avert? I’m not a fan of extended warranty but this could easily justify it. Seems like should be a recall item.

 

[RonR]

Clearly a thermal cycling problem. The stud that has sheared broke under the bolt so I would guess it's mostly warping of the manifold and thermal cycling. There is a company in canada (?CR Engineering) that makes a thicker manifold but those have also had issues. Since it has lasted past the standard warranty period, I don't think it will ever be a recall. I would guess that the next gen EcoBoost would likely have an improved design.
The studs are hard to get to so I don't think anyone would want to do preventive maintenance. I'm sure some ecoboosts will never have this issue so why bother. You may even make things worse if you over torque the bolts.
If anyone reading this has used the beefier manifolds, could they report?

 

[RonR]

Just completed a 2 month cross country trip with over 4000 miles with no issues. Also still do not have an audible whistle so despite the broken stud the manifold still has a fairly good seal. It was a good thing to wait since there is now an updated factory manifold available that has an extra stud in the area where my stud has broken off. I've decided to leave it alone until I get an audible leak or some codes.
Still a pain and an obvious design flaw once you look at the stud spacing on the manifold. It's a shame that such a stupid design flaw made it's way into an otherwise stellar engine.
I still would like to hear about anyone, in the seattle area, that has a shop they would recommend for the work?
Thanx

 

[Randomtask42]

Just completed a 2 month cross country trip with over 4000 miles with no issues. Also still do not have an audible whistle so despite the broken stud the manifold still has a fairly good seal. It was a good thing to wait since there is now an updated factory manifold available that has an extra stud in the area where my stud has broken off. I've decided to leave it alone until I get an audible leak or some codes.
Still a pain and an obvious design flaw once you look at the stud spacing on the manifold. It's a shame that such a stupid design flaw made it's way into an otherwise stellar engine.
I still would like to hear about anyone, in the seattle area, that has a shop they would recommend for the work?
Thanx

RonR, did you ever get this repaired? Mine just started whistling and I'm in the Seattle area.

 

[RonR]

I'm glad I did not replace it in 21. There is a new design that uses all the bolt holes that are already in the head. Seems an obvious screw up but I have heard of no support from Ford.

Despite the last two bolts being broken, I still have not heard any new noise and can't detect any issues so I have not replaced them, yet. I did get two quotes of about 4000, one from the Ford dealer in Issaquah (who I have used before and seems honest) and from an independent that I can not remember. Most folks talk about dropping the entire engine but a few claim it can be done in place. I don't know the reality. Regardless, if that much stuff is being moved / taken apart, it would be good to also replace any other potential failure items. But, (at least for my Seattle area 2017) there do not appear to be any obvious items beyond all the gaskets and seals that are replaced as part of the job.

Also, there is at least one company that claims a better (more power, more MPG) manifold design that may be worth looking at. (Google will come up with a link) sadly I think they are currently back ordered. If you are already spending about 4000 what's another 100 or two.

So I'm still waiting for an actual performance reason to do the repair and am currently side tracked by a P0306 misfire that is likely a coil pack. Tomorrow's adventure.

Let me know what you do and find.

Thanx
Ron

 

[RonR]

Just got both sides replaced at the Ford dealership in Issaquah. Painless but expensive (OK, I think the price was fair and the dealership seems fair). I pulled the trigger once I got a P0420 (weak catalytic converter) code. No other codes despite both rear studs being broken. Sadly the new manifolds did not clear the code and it is likely that the several months of slight leakage before the cats may have contaminated them. No other codes and no change to noise, gas milage or power with the new manifolds. Will have to see if some after market treatments might clear it or just live with it.

 

[RonR]

Heads up on eco-boost exhaust manifold. I had two studs break so knew I had a problem but had no symptoms, no obvious exhaust leak, no sounds, it all seemed good. I finally broke another stud and pulled the trigger to get both manifolds replaced with the upgraded version. Shortly after I got the dreaded P0420. It seems that running for an extended time with even a small exhaust leak can degrade the cats.

 

[pbethel]

Heads up on eco-boost exhaust manifold. I had two studs break so knew I had a problem but had no symptoms, no obvious exhaust leak, no sounds, it all seemed good. I finally broke another stud and pulled the trigger to get both manifolds replaced with the upgraded version. Shortly after I got the dreaded P0420. It seems that running for an extended time with even a small exhaust leak can degrade the cats.

You don't think the misfire code had anything to do with cat degradation? Misfires will quickly damage a cat.
I think that is more likely the cause than slight upstream exhaust leak.

 

[RonR]

Never had a misfire code. P0420 is a cat degradation code (or O2 sensor degradation plus a few others).

 

[pbethel]

So I'm still waiting for an actual performance reason to do the repair and am currently side tracked by a P0306 misfire that is likely a coil pack. Tomorrow's adventure.

Sorry.
I must not understand what this post said.