Help diagnosing coolant leak

Hi guys. First time poster here, but I have been lurking for quite some time. Your DIYs have been an incredible help and thank you so much in advance for the sense of empowerment of saving hundreds of dollars from shifty mechanics.

So onto my problems. The lean codes came on both censors, so I replaced my air intake boots (the culprit was the Y at the bottom of the lower intake), my fuel filter, the DISA seal, my air filter, and added a full tank with Chevron Tech. The car was running like new and the light went away. Then one evening, the CEL came back on reading out the same codes (P0171 and P0174), as well as the low coolant. They both appeared at roughly the same time. I filled up the coolant making sure to monitor the levels.

Over the next couple of days, the car developed an incredibly rough idle. It's to the point now where it stalls out on most occasions. Upon start up, there is also white smoke coming from the exhaust.

The coolant looked to be a pretty significant leak from the puddle that began to form, so I used Stop Leak as a temporary fix to buy myself some time (I'm also not made out of money). The severity of the draining is gone, but that's not to say the issue is fixed. I just needed to buy myself time.

I was taking out my air intake today to clean the ICV and throttle body thinking that this might be the culprit with at least the stalling. I then noticed where a pooling of coolant had begun from wherever the leak was. I got up under with my iPhone and just started taking photos of everything. You'll see some hoses with visible gunk on them and others where dripping has visibly occurred over them. I know these photos aren't the greatest, but I figured they could at least give somebody with a keen eye a sense of what and where it could possibly be wrong.







So with all your combined prowess, does anyone have any ideas as to what they think this could be given the location of the drips? What hoses, valves, gaskets, seals should I look into? Is my problem even just a simple leak to begin with? Is this something I can fix from underneath my car (because if I already have all the intake out, I would much rather take care of it now)? And could there be any correlation between my problems/symptoms with the intake and the coolant system?

I can also provide larger versions of these photos or go take more.

Cheers!

I'll start, but you have to do a bit of studying up.

Before you took things apart, I would have advised to top up with distilled, since you'll be draining it mostly anyway (if it's of unknown quality)...and by top up...I mean fill to between min and max.

Then clean up all the residue you see. Then start car and find the source of the leak.

I have keen eyes but no idea what I'm seeing! LOL Clean things up and look with good led flashlight. Don't assume, though, that the reason you have a leak is simply that say, the ET cracked...it may have cracked for a reason...like thermostat not working right.

After the stop leak stuff...I'd drain completely after you identify the culprit and fill with just distilled...(Maybe remove therm from therm housing and run it with water without therm. Besides clogging up passages, I think the biggest risk comes from messing up the therm...but maybe not. I'd flush with distilled...at least one time...maybe twice.

This is a good chance to consider the Mango approach...if you want to actually fix your system without knowing what's wrong with it...if you have $3-700 you can have a whole new system...otherwise, you have to figure out what's wrong.

See bimmersgarage's diy links on diagnosing cooling issues. There have been so many cooling threads of late, I can tell you all the info is around and handy. Do some work...remove underskirt at least...and don't trust anyone who says it's leaking from a particular place.

The leak might not be the reason you have a leak...start reading until you puke...but you'll end up being fine.

Inspect around ET, Radiator, hoses, under therm and wp housings, ET cap, fittings...good luck!