Folks,

I was removing the undertrays for another matter, and found that a few screws allowed me to easily drop #8 below, the undertray for the radiators.

Pulled about an inch of crap out, leaves, junk and so on. If you drive in the country a lot, you may have a lot more caught in there.

On my BMW, I had four inches of junk there, and cleaning it out improved my AC quite a bit.

FYI, YMMV.

Panthera

 

Pathera999,

Thanks for the insight. I planned to clean around my AC condenser in the Spring as my unit doesn't perform as well at lower RPMs.

 

Thanks, J. To your comment on AC performance, I had a problem on my BMW, where refrigerant dropped slowly (and within BMW leakage limits) over 10 years to about half what it should be. A simple pressure test didn't catch it. I had it refreshed (sucked out the old, replaced it and topped up the refrigerant oil) for a complete fix. Should be $150 or so at any competent shop. No need to use Jag for it.

A lot of people don't realize that most AC systems leak a miniscule amount under normal usage. After 10+ years, it's noticeable. FWIW, auto store recharge kits shouldn't be used. There's a specific weight of R134 required in the system, 700g, as well as 130 ml oil, and it shouldn't vary. If I recall (might be in error), the Denso 7SEU17 also requires a specific type of Denso oil.

Specs attached for the 07-09 XK 4.2

 

Have been under mine fixing a small leak on the vacuum pump and witnessed the same in all 3 heat heat exchangers.

Found a significant amount of crap I there. Cleaned with compressed air but has anyone any ideas on how to better clean between the fins higher up? It only about 15mm between radiator and AC evaporator. Is there a tool I can connect up to my compressor or am I going to have to knock something up myself?

The foam baffles had virtually disintegrated too which can lower cooling efficiency. I know from experience on my day job how much difference having the baffles around the heat exchangers make.

Definitely something worth keeping an eye on especially if you live in a hot region.

 

Can't speak to the baffles, but I used something relatively small from the bottom, like a bent coat hanger with a small hook on it, to loosen the crap up and pull it out the bottom. I was careful to keep away from the fins, and it worked for me.