Rusting Exhaust Manifolds GRFE engine. Should I do anything?

I suspect many of you have the same problem, unless you live near the desert or your truck is new. Truck is 13 years old, 130k miles. Runs fine, but dont know if a problem is developing or I should paint these, etc. Took pics of the Tacoma and the 4runner. First 2 05 Tacoma, last 3 07 4runner.

Thought about painting them, to try to prevent further rust. Took a temp 1 min after running the truck 20 mins for a short drive. 400. Seems like high temp paint would work. Lowes has 1200 degree paint which I used on the other end of the exhaust that works great.

Has anyone done anything to them? Are yours rusted? Have you painted them? Or do you just let them go until a sensor tells you its time to replace them.

If anyone has replaced them, did you make it to 200,000 miles?

 

No, that's completely normal. They're cast iron; your entire body and frame could rust away to nothing before the exhaust manifold would have any issues due to rust. Cracking due to a hot manifold getting doused in cold water from puddle jumping is more of a threat to a manifold.

 

those look clean to me

mine look a lot worse and I wont touch them until there is a hole

Paint wont last long IMO, when running up hill on a long grade, you would be surprised how hot they get

 

Exhaust manifolds rust. Paint them if you wish... You do seem to have a huge amount of rust, but I don't live in snow country.

 

Yeah I suspect its more common in the snow belts. PA truck originally, so damage was done before I go it.

 

I'm almost 280k they pretty much look like mine.

 

With most cast iron once it builds up a certain thickness of oxidation (rust), it won't oxidize any further. They'll look like hell but the chances of a hole rusting through is nil.

Plus if you try and pull them before you absolutely have to, you may end up with other problems like having to replace manifold studs. Those nuts look pretty bad - I wouldn't touch them unless I had to - and with a lot of heat and Kroil before I put a wrench to them.

 

Mine look the same, rest of the truck is rust free, not going to do anything until I get URD headers and full exhaust, then I'll paint the new stuff

 

This right here!