I'm tracking down a pinhole coolant leak currently, so popped off the 'plastic shelf' piece of trim right above the radiator core. It pulls straight up...just has several locating friction clips holding it underneath. The rubber weatherstrip around front of the hood just pulls back towards the center of the engine bay and out of the way, so then you pull up the trim piece. Mine had a small diameter coolant return hose held in metal clips along the underside of that trim piece, but your engine may differ.

As I'm looking around in there with a work light to see if I can spot any tell-tale stains from a leak source, I notice there is a heat exchanger (power steering, IIRC) sitting right in front of bottom of the A/C heat exchanger, which itself is mounted just ahead of the radiator core. The transmission cooler heat exchanger on my TDI is mounted above and out in front of this one I'm looking down at.

On my Q7, the entire void space in-between the power steering cooler and the A/C heat exchanger was filled with bugs and other debris all the way across the width of those two units. It was packed from top to bottom, so there wasn't much, if any airflow getting through there and passing through the A/C exchanger, and subsequently the radiator core was having reduced airflow along that same section width, etc.

I have never been happy with the A/C performance in my Q7. After I (carefully) cleaned out the accumulations from between those two heat exchangers and then rinsed both to clear their fins as well, I took it for a drive. It was a pretty warm day out in high 70s (F) and sunny, and my black on black Q7 was nice and toasty inside from sitting parked in the sun.

The A/C system surprisingly responded very quickly and is now blowing cold-cold rather than moderately cold air I was getting, which was making me think I might have had low freon charge or other problem issue in my A/C system. Turns out, the A/C heat exchanger at front of car was just partially blocked by all the accumulated gunk and bugs...it was thick and dense...almost like a felt moving blanket; it took me some time to get it cleaned out.

This is just something you can check directly, and correct easily, if you find your A/C to be somewhat lacking in cooling power; this could be your problem. It was on my Q7. Do beware you'll cut up your hands if you don't wear gloves when reaching/ working in this area.

FWIW: I always use a low pressure misting spray when I handwash my car to help clean out the heat exchangers and intercoolers, so I had a false sense of how clean this heat exchanger area actually was because you can't visualize the space where the accumulation occurs unless you remove that top trim cover over the radiator core and look straight down from the top. It's just hidden from view where it accumulates.

Hope this helps somebody out there!

 

I can't remember how mine did over the summer last year, but it's something I might check out myself. I have the 3.0T SC engine though, I'm wondering if the whole cooling and AC systems are set up the same from model to model.

 

The location of these heat exchangers I'm referencing to appears standardized regardless of the engine.

The primary difference I've seen amongst the myriad engines offered in this Q7 is what size/capacity radiator core you get is based on the engine output. The 'upgrade', higher output engines come equipped standard with the highest capacity radiator, etc. (4.2 V-8, All TDIs, etc), while cars equipped w/factory towing option get the absolute best cooling capacity, as that option comes with a high capacity radiator and (towing specific) extra capacity cooling fan rated 600 watts, rather than the standard cooling fan the rest get, which is rated 450 watts, etc. The smaller cooling fan is 300 watts and shared by all models/engines.

 

oh nice, didnt know that, so there is more benefit to tow package, then just towing.

 

Mine never has cooled as well as all my other vehicles. Blower is fine, just not as much air movement or cold air. Did you happen to take any photos of this, or do I have to investigate myself? lol

 

what I read somewhere, if it has 4 zone AC, then it has two ac compressors, or two evaporators, one separate for rear seats, and that for sure would make the car cool way better. Its just logical it does.
And panoroof I can tell right away heats up the interior so fast.
I mgiht have to look into wrapping it/tinting to mitigate that

 

I took a pic, but it was after I cleaned out all that accumulation in the space between these two heat exchangers, but was zoomed in pretty tight as my intent was recording the part #s off the stickers on them for reference. That's how I know for sure the one in front of where the clog formed is the power steering fluid cooler...got the part # off it.

Like said, it's actually super easy to yank that top trim cover that looks like a bit like a shelf that sits just inside the hood gasket, etc. The hood gasket is just a channel-fit type...no adhesives on it, so it just pulls back easily. Once clear of the trim piece, the plastic cover/trim piece over the radiator just pulls straight up to remove the friction clips holding it in place, etc. This is one of the easiest DIY checks you can do. However, if yours is clogged up solid like mine was, you do need to be really careful with what you use to dislodge the accumulated gunk in that space to avoid damaging the fins or body of the coolers on either side, etc. It's an awkward space to get at it unless you have something like yardstick/meter stick laying around. I improvised with a laughably oversized nylon zip-tie...a really, really big one. Wear gloves if using something shorter, as not a lot of working room and lots of sharp edges...lots.



The MONEY shot...View from top: Nose of car to the left; there's also another cooler mounted higher up and to the left, out of frame. This one is the power steering cooler on left, and as yet unknown on the right. Between them is the gap where it was completely packed up full of gunk...very little if any air passing through these two heat exchangers as a result, and the ones stacked behind them (A/C and radiator core) would have reduced efficiency as well from reduced/blocked airflow all the way across the bottom.