Owned 6 100/LX series (99-06) and never exhaust issues
Hope this does not come back and haunt me.
Must be the dry heat
Most common is the cracked manifold, which you've beaten the odds already. You get to LV NV much
As far as exhaust manifold gaskets leaking, well I've not seen yet either.
This is not a case of exhaust leak fix. I'm swapping parts for 100 series 2UZ VVT to a long block of a GX470 2UZ VVT from WI. Exhaust manifolds are just some of what parts must be swapped to fit a 100 series. Had exhaust manifold been left undisturbed it wouldn't be an issue, at least not for a very very long time if every. So it's kind of a don't look don't know area.
Isn't the precat temp hotter than 700°
Good question, IDK. But this stuff and earlier stuff like "Copper ( 650 F)" is made for exhaust use. I wish they'd disclose continuous temp rating on the package and expected life in use..
Condensation/moisture present which aids corrosion. Crevice or galvanic corrosion? I would not lose sleep over it. Just clean it up and slap on new gaskets/nuts.
Thanks for the addvise. This engine is from WI (moisture), which I suspect is why I'm see this. Not something I normally deal with, but never looked before either. Have you dealt with it?
No, there is a certain amount of crush that forms the gasket when it is compressed when torqued up. This allows the gasket to fill the imperfections, a heat cycle aids this. That is why you should recheck the torque when cold again after a few heat cycles, not always necessary it Is just good practice.
I agree, they are designed to crush and conform to matting surfaces and minor warpage (less than .50mm).
That said; I'm also mindful that they're design for head to manifold surface on the factory floor!
Ps, it might have some kind of coating to help, not always the case. All that matters really is that the gasket is designed to be used with no added sealants, it just isn’t required.
Total agree, it is intended to use without sealant. In general, I'm against adding thing not recommend by Toyota and I've only used Toyota seals & sealant (FIPG).
The crush gasket that fit onto the down pipe(cat) are excellent in my opinion. The best gaskets I have fitted, beats the cone types. If you have ever worked on a car where they have installed the exhaust with exhaust putty, you will find that the joints will usually leak first as the exhaust putty breaks down. Some vehicles now only have the manifold gasket, the rest of the system is gasket free, they just use a metal sealing clamp over a tapered joint.
Those gasket do look good and appear (with thick pink coating on each side) designed to fill in minor pitting.
I never dealt with exhaust putty. But have used the soft asbestos gasket in the past, designed to fill pits and compensate for moment (expansion). Those work good.
This pitting is minor and a sealant would probably not be necessary in this case. The most encouraging post was from
@rockcrawlingyota stating he had five times worst without issue when he changed gasket.
I'm curous as to why you replace your gasket
@rockcrawlingyota in the first place?
I'm hopeful, more will come forward and share their experience, especially from rust belt. Whereas this 06 engine is not bad, I can see where older engine from rust belt and salt water areas could be very bad if exhaust manifold removed and heads cleaned-up.
