Warped manifold

[***VX*R8***]

How common is it for the turbo exhaust manifold to warp where it meets the head?

I've been having to tighten the manifold bolts every so often and decided to get the manifold machined flat.

The guy at the shop (head reconditioner) suggested buying another manifold as it will need around 5mm taken out.

 

Ford want $1200 and "I have heard" it's very common so a used one will likely be just as bad.

 

Has anyone had this issue and if so how did you resolve it??

 

ps- the turbo to manifold studs and nuts have held strong and the gasket hasn't leaked there, only from manifold to head...

 

Thankyou.

[k31th]

There isn't even a gasket in between the turbo and manifold normally, but that's the joint that loosens through heat cycles, normally, not so much the exhaust manifold bolts

 

It's also normal in these cars to have to tighten the exhaust-manifold-to-head bolts occasionally. it's worth doing every time you service the car. If it's not leaking boost, I wouldn't worry about it being warped. If you're really concerned, replace the exhaust manifold gasket with a new one and properly torqued it should be fine to seal up

[JETURBO]

Superrrrrrr common on the FG, they’re literally a banana when they come off, DO NOT get it machined as already mentioned to you due to the amount needed to come off to get it “True” 

 

The FG turbo exhaust manifold is very flexible and placing it on the head with a new GENUINE factory gasket starting in the outside (1/6) taking up then applying pressure then strategically working inwards (5/2 then 3/4 ) will bring it in and using the correct sequence and torque spec will have it sealed beautifully 

 

the option at this point to go a full set of head to manifold studs with a coupled “crushed” nut and Nordlock washers to compliment the procedure will have it set and forget. 

 

There is always a chance that the head port face could have warped if you leat a blown gasket go for a long time and then you’re stuffed and that will need a “face up”, pretty rare though 

 

cheers thanks, ta 

[MurdoK]

@JETURBO have you seen similar issues with the inlet manifold on fgs?

[JETURBO]

No, they’re nearly perfect every time 

[***VX*R8***]

58 minutes ago, k31th said:

There isn't even a gasket in between the turbo and manifold normally, but that's the joint that loosens through heat cycles, normally, not so much the exhaust manifold bolts

 

It's also normal in these cars to have to tighten the exhaust-manifold-to-head bolts occasionally. it's worth doing every time you service the car. If it's not leaking boost, I wouldn't worry about it being warped. If you're really concerned, replace the exhaust manifold gasket with a new one and properly torqued it should be fine to seal up

Yeah I put a gasket in and replaced the studs and nuts when I changed the turbo (GTX3582R).

Very happy with how they held up though. Really wish I hadn't just unbolted the turbo to get the mani machined now though, lol.

 

34 minutes ago, JETURBO said:

Superrrrrrr common on the FG, they’re literally a banana when they come off, DO NOT get it machined as already mentioned to you due to the amount needed to come off to get it “True” 

 

The FG turbo exhaust manifold is very flexible and placing it on the head with a new GENUINE factory gasket starting in the outside (1/6) taking up then applying pressure then strategically working inwards (5/2 then 3/4 ) will bring it in and using the correct sequence and torque spec will have it sealed beautifully 

 

the option at this point to go a full set of head to manifold studs with a coupled “crushed” nut and Nordlock washers to compliment the procedure will have it set and forget. 

 

There is always a chance that the head port face could have warped if you leat a blown gasket go for a long time and then you’re stuffed and that will need a “face up”, pretty rare though 

 

cheers thanks, ta 

I thought it would flex and bolt up straight too.

Last time I had it off someone told me to get it machined but I figured it would be ok. Each runner face (?) is straight.

Just the manifold as a whole is warped.

 

I bought a stud and copper nut kit last time but found I couldn't get the manifold over the studs due to something being in the way (possibly PS), but I will try again.

Do you loctite the threads going into the block? I'm guessing no.

 

I'm confident the head is still flat/straight. The bolts would loosen over time but there wasn't a major leak.

 

I already have some Nordlocks ready to go too :D

[ratter]

we have seen quite a few FG's break the rear exhaust stud in the manifold and put it down to the amount of run out in the manifold combined with the heat in that area

[4321]

Iv'e never been a big fan of machining relatively thin parts like this (and brake rotors) they are 'X' thick & they bent & now you machine them down to 'Y' and expect to last as long? Try a gasket between the turbo & manifold with new studs & nuts, new ford gasket for manifold & head, torque it up as JET said and there's a pretty good chance it will be good. As a maintenance thing they should be checked for correct torque every 2nd or 3rd service 

[k31th]