Warped exhaust manifold?

[LedFloyd900]

I just put a new remanufactured 3VZE in my '92 T4R and now I have an exhaust leak. I've tried everything to fix it and can't even pin point it. I called a mechanic today and he told me that the old manifold I'm using is possibly warped and not seating on the block/gasket correctly, causing the blow by of the exhaust gases. Does this sound likely? It's the only thing I can think of because I used new gaskets and torqued every nut to spec with new lock washers. Any advice would be awesome, I sound like a drug dealer in his ghetto car at the moment

 

[slacker]

yep , highly likely

 

[Hyde802]

Could be. put a straight edge on the manifold mating surface and see if its warped.

Did you try just replacing the gasket? If so, can you see on the gasket where it was leaking?

 

[gtgt_bangbang]

have those manifolds flat ground

... the old manifold I'm using is possibly warped ...

agree possibly warped. I think the spec is a couple mils only. 5?

Mine were not flat and had some eroded spots too, so I had them flat ground by a shop with a Planchard (Blanchard ?sp?) grinder.

It was kind of spendy at 70 for the pair, but there is a bit of set up on that odd shaped part and and now factory fresh flat.

OF course these should seal better and won't strain the head ( iron wins over aluminum almost every wrestling match).

Don't pooppoop that notion - Toyota FSM actually instructs to install & torque the exhaust manifolds ( and accessory brackets btw ) BEFORE installing the head, to do all the straining of the head BEFORE torquing ( think "torque plate required", when doing over bores) .

of course if your manifolds are warped at that point, all bets are off, the head is NOT going to respond well to the influence. I realize you cant do that with a long block drop in, but if you have the choice , why not ? Its easy on a stand and only slightly more impossible with motor in the truck.

I happen to have a couple different gaskets sets to compare... again Felpro wins . Pantech manifold gaskets were steel of some sort, but then they sprayed them with stainless or aluminum paint to look purty and probably hide the crappy steel corroding right away.

Felpro just made them out of quality stainless to begin with, and left them naked.

Sometimes you can pin point a noisy leak , like an exhaust chuff, using a hollow tube for a stethoscope.Hold it to you ear and move it around and listen for whispers. For gods sakes dont let it touch the fan when its connected to your head. Thats VERY loud

 

[LedFloyd900]

Yea I thought about taking it to a machine shop to flatten the surface out but I just got a completely brand new one from partsgeek for $113 after everything, and that included the passenger side manifold, crush gasket, all new studs, and a new manifold gasket. And Hyde802 I did use a brand new gasket that came with the kit I got, and after close inspection with a flashlight and mirror I discovered a tiny tiny bit of black remnants but around 2 of the 3 ports. And I say tiny because I've only gotten maybe 120 miles on the new engine, so it hasn't accumulated too much yet

 

[gtgt_bangbang]

well thats cool - I think you are saying you did NOT have the new manifold on the build when you had a leak? Thats good.

and since you found traces of blow by, sound like a plan.

But FYI, manifolds may crack, they may warp, but they rarely wear out. I saved my slightly scruffy oem ones paying the machine shop a bit.

With all the thousands of struggling chinese factories looking for parts to knock off, but little in the way of engineering, QC or proper materials, cheap parts are often expensive.

Its like finding a great deal on an Appel EyePhone. The best day is the one before its delivered.

I replaced the studs on both ends ( PS a MAP torch turned those suckers orange, alternated with penetrating oil & some hammer whacking to loosen up the corrosion let me back out the crusty manifold-to-pipe studs with no breaks)