What are common failures with W210 A/C Systems
 

The A/C system in my E300 isn't blowing cold air. I'm pretty sure its got a leak on it, but haven't pulled any codes for diagnostics yet to really determine. I realize this is faux pas, but my mechanic and I filled up my completely empty sytem over the weekend with fresh R124. 2lbs in total. Everything worked great once the system was recharged. Ice cold. Where are some common areas on the A/C system to cause leaks? Can these leaks be fixed via DIY, or should I have a pro do the job?

The compressor/dryer has been replaced on the S500 3 separate times! My hope is that this isn't the case for the E300.

Temp sensors are common failures, evap temp sensor is the most common.

Good to know. Thanks,

As for leaks on these cars, they're no different mechanically than other TXV system of the era. Plenty of things can leak.

Condensers (cheap and easy) and evaporators ($$$) do occasionally leak. You need to get someone with a sniffer to go over it to see if there's an easily-identified leak.

I've had condenser issues on my W210 and my W202 series cars. In both cases the failure mode was the same, a rock/pebble hit the condenser and punched a small hole in one of the condensing tubes.

These newer condensers are paper thin, they do a great job of heat transfer but they are not nearly as tough as the condensers on some of the older models.

As Matt points out the "upside" is that a new condenser is only a couple hundred dollars and they are not hard to change.

After having a AC compressor fail on a 190E. we found out that it was out of oil. After that I had my mechanic pull the compressors on every Benz that I bought and put in an oz or so of oil if they were low. My '87 300E has the original compressor as does my '93 300CE and the '95 E420.
Just my observations on compressor maintenance.
Anziani

How do you tell if your system is low on oil?

My experiences
 

My E300 (1996) has a leak in the dep dark nether regions of the dash but small enough to allow a recharge or 2 a summer to be operable. Last month I had the recharge done and it worked for 2 days then nada. I pulled the code and got the electromagnetic clutch (compressor right?) So a mechanic looked at it tried to reset with no avail then he tried jumping the compressor and found it was toast (confirmation of my findings for $65). Here's the crappy part unless someone else can steer me to a better solution - Compressor ~$600 , receiver/drier ~ $90, oil, labor and a recharge will come to ~$1000!
Not bad buttttttttttt - the car has 288K miles on it and I drive 40-50K miles per year. Had it been $600 or so I would have gone ahead. Can I get a remanafactured compressor?

Thoughts? Comments? Suggestions?

Thanks
Hot as hell

You might get lucky with a reman unit, might not. You could do most of the labor, getting the compressor changed and flushing the system (but I would recommend adding a new condenser to the list). It would be good to check for leaks using the old receiver/drier before installing the new one - do that only when you're ready to evacuate the system.

You can buy a new Denso compressor on Ebay (made in Japan) for $309 shipped or a re-manufactured one for $209. Search for Jensen Auto. I just replaced my compressor with a new one ... I figured the extra $100 was worth it. Vacuuming the system right now, hopefully I'll feel some cold air soon. ;)

If you do the work yourself, Autozone loans out vacuum pumps for free (deposit required) so that'll save you ~$100.

Good Luck :D

Thanks
 

This helps alot - if I source the parts it seems like I might pay ($300 to 400 + 25+ 10 + 25+ 50 misc) $400 to 500 and how much labor is involved? Compressor looks like 0.5 to 1 hr, drier/receiver 1hr + vacuum the system and then a refill 1 hour -at most a 6 hr job. This would come to 600-800 right? Please correct if my guesstimates are off.

thanks