Soooo....on the way home from work today, I am about 1 mile from home. Leave a stop light and felt a shudder and my check engine light started blinking...wtf....seemed to be running ok, but still blinking. Get about 1/4 mile from home, notice my temp starting to climb, but generally running ok (can you see where this is headed yet?) Get in the driveway, shut it off and pop the hood to inspect (it didn't stall). Coolant tamp empty...rut roh...go look at TB and I can see coolant below the TB and on top of the trans....Let it cool for a few and pop the rad cap....nothing...DOH! The upper intake is a GM, but it has a date code from '05 (before I bought it). I can see the gaskets are just the black plastic. So, I pulled the air box and throttle body....wow...my UIM was full of coolant! Great! So, I sucked as much of the coolant out as I could (about 40 oz!), pulled all of the plugs (nothing came out). I pulled the oil dipstick, oil was not milky. Drained the oil, not milky at all. So what do I need to do next to make sure nothing else gets messed up? The car has 230K miles on it, so I don't want to dump a ton of money into it. I can swap the UIM and gaskets myself, not worried about that. Links to what exactly I would need would be great!

UIM
Gaskets
anything else?

Pics coming soon....

You will need to change the UIM, it'* the stove pipe for the EGR that'* gone bad. Hot gases from the EGR heat up the plastic and it fails. Sounds like you did everything you need to to protect the engine.

I think that is exactly what happened. The area where the stove pipe comes thru the manifold definitely doesn't look like a clean machined hole. Thanks for letting me know I did what I could to make sure everything survives. Here are a couple pics I snapped with my cell

First pic is intake

Wow, it'* nasty in there. I wonder if that happened withing a short time, or over a period of time

Second is throttle body
WOW, that is nasty! There is like 1/8" of buildup sticking off of it!

Upgrade to the aluminum intake if possible?
Dan'* right, you jumped on the issue quick and prevented other possible issues. Good job.

Ya, that'* gooey, you got lucky and didn't fill a cylinder and try to start it.

Well, I just finished ordering the APN UIM and the lower gasket kit. Hopefully they ship quick!

Upper and lower intake manifold are off (about 2 hours last night to get everything off). So far everything has been pretty straightforward, no real surprises. Intake manifold kit and gaskets shipped yesterday form Indiana, so they might be here today. The lower manifold was really nasty. All kinds of sludge. Lifter valley was nice and clean though. I poured a couple quarts of walmart oil down the lifter valley and rotated the engine (via crank bolt) to flush out any coolant that may have gotten into the crankcase. I wonder if the sludge was building over time or built up real quick when I started pouring coolant? I checked out the upper where the EGR tube goes in, definite point of failure. Stupid POS. Here is a pic of the lower manifold before I pulled it off. Clean and prep will be tonight and tomorrow.

That looks like it built up quick. Is it all gooey or dry?

Food for thought.

If you are looking to bullet proof it, consider plugging the holes in the UIM for the coolant passages. Or plug the LIM with 1/4" NPT plugs. That way w/o coolant flowing past the EGR you will never have another problem with this issue.

Sure the kits are supposedly better, but honestly..why take the chance when we know that blocking the ports has no negative effects?

Sludge/dirt:
This is competely normal, except the gallon of coolant. The PCV does spit some oil up into the LIM and the EGR tosses carbon in there as well where it sits until we go into it. The TB is the same issue. It'* right by the EGR.

It is all slimey and gooey, pretty nasty.

First time I have heard this. Any links to more info? Possibly even a how-to?