I noticed the first runner on the LIM was rusted and the others were fine. What reason is there for this???
The car has only been sitting for a month

 

Rust? Requires Iron, and the UIM is made of Al, not Fe... Are you sure its not Al Oxidation? Is it ornage? If it is then... well... i dunno

EDIT: example, both the extereior of these manifolds are oxidized: http://sheepdog.ar2engineering.net/p...s/PICT0070.JPG

whereas this tranny input shaft is rusted: http://sheepdog.ar2engineering.net/p...s/PICT0027.JPG

 

Al actually cannot rust at all.

-Joe

 

Mmm, I know, I had to edit. I was thinking maybe part of the manifold has some sort of composite, but Fe and Al is a pretty strange mix. What about the thermal sensor on the runner nearnest the firewall... It could have gotten wet and left some rust run marks maybe...

 

oh it's rust, that's why I'm sayin WTF??

 

is it surface rust, or is it like residual rust that came from someplace else and just stopped in the horizontal intake runner?

 

pretty sure it must be surface rust because it is all around in the runner, not like it leaked in, and there is no rust on the gasket surface

 

Can you get a pic of this?

-Joe

 

not possible to be rust on the AL it self, its either from up stream or some kind of oxidation.

 

which runner is it, 1st facing firewall or bumper?

 

no pics, no digi cam
it's the one closest to the bumper

just went for a second look, and it is on the UIM runner too.

Bad Injector?

 

ok, does it look like this? Because this is oxidation:
http://sheepdog.ar2engineering.net/p...s/PICT0026.JPG

 

nope it's orange

 

what the heck.. its gotta be residual from something prior to the LIM... whats the UIM look on the same runner?

 

same

 

It's probably just the 16+ year's worth of the oil metering crap coating the surfaces, see if acetone dissolves it (with it off the car, of course) I used at least a quart of acetone to clean mine up during the rebuild...

 

Can you tell if its before the oil injectors than?

 

I kind of got that too on my NA.

When I pulled the UIM off I saw some nasty orange like stains in one runner only.

It also had small little white deposits.

I am concluding it was a bad injector leaking.

BTW I used 3 cans of brake cleaner on the inside of the UIM. IT came out black due to aluminum tinging but also a lot of crap.

I'd say since the UIM is off send the injectors out to be cleaned.

www.cruzinperformance.com 11bux each.

Then buy some brake cleaner(no residue) and clean that bitch up.