Cold engine = cold AC, warm engine = warm AC? - Page 4 - PeachParts Mercedes-Benz Forum

#46 07-03-2006, 12:58 AM

Quote:

Originally Posted by redassag00

I need all the help I can get,....better get some foam wrap and tie wraps from the hardware store!
Thanks

I just did that. Home Depot sells foam insulation for 1/2 piping in about 5 foot lengths for a couple of dollars (dark gray color). It is easy to install on that AC line with a few tie wraps. It looks almost stock, well close enough not to be ugly.

redassag00 · #47 07-03-2006, 10:15 AM

Quote:

Originally Posted by Craig

I just did that. Home Depot sells foam insulation for 1/2 piping in about 5 foot lengths for a couple of dollars (dark gray color). It is easy to install on that AC line with a few tie wraps. It looks almost stock, well close enough not to be ugly.

COOL!
I'll swing by there today!
WOOHOO!

hookedup4door · #48 07-03-2006, 03:34 PM

Is there a link with a pic of the monovalve? Where is it located? I'm having bizarre ac problems too and I'm looking for troubleshooting tips. I just added insulation to the ac line, pressure washed my condensor and double checked the pressure in the line. No luck. I can hear the ac kicking in when I turn it on but air from the vent is 'cool' and eventually turns to "I need to roll down the windows" temperature.

Quote:

Originally Posted by sunnyintx

Sorry for being so long getting back on this, but I thought I should say there are "new" symptoms as the weather has gotten hotter, in case someone is following this thread for their own needs.

Now that it's hot, it naturally takes longer for the engine to cool. A couple of times, I've popped the hood to let it cool while I was in an appointment (talk about getting some strange looks!), and if there was enough time, I'd be cool on the next leg of my trip. If not, well... I'm grateful the car has good working windows!

The monovalve kit is in, and I've looked at both the instructions on the forum and the monovalve in the car. Looks like a cinch, and we woulda done it this weekend, except....I can't find our angle driver, and I can't get to those flat screws without it. It's just a tiny bit too far under the edge of the windshield.

DH has the car this week while I drive the newest addition to our stable and get a few things straightened out on her, so if he doesn't find our angled driver (or get frustrated and buys another one!), he'll run by our indy and ask him to do the switch-out during lunch one day this week.

I'll keep you posted on the results. I have great hopes that this is the solution to this particular issue with the AC, since the more I read about the monovalve, the more it explains my heating problems in the winter, as well.

Now, one more question -- the '84 we just bought has a fan that's twice as strong as either this '85 or our other '84. It's WONDERFUL! I've been through all the service records back to the original invoice (only 3 POs, the original owner didn't sell it until 2 1/2 years ago, and he was completely anal about repairs!), and I don't find any replacement of the blower motor. I'm going to re-check, but what would make the blower blow half as strongly on our other two? Switch (we still have two speeds -- slow, and slower), or what?

If anyone's got any thoughts, let me know. No hurry, but it would be cool (pun intended) to figure this one out and fix it.

#49 07-03-2006, 08:41 PM

Quote:

Originally Posted by hookedup4door

Is there a link with a pic of the monovalve? Where is it located?

I don't have a photo handy, but it's the electric valve in the heater line on the firewall, right next to the battery. If you need a photo, let me know and I'll take one and post it.

sunnyintx · #50 07-03-2006, 09:02 PM

Standing at the front of your car, looking towards the windshield, look at the battery on your left right under the windshield. Next to that, moving right, is a space, then a 3" x 3" x 5"h (+/-) boxy thing bolted to a bracket on the firewall with two bolts. Unbolt those two bolts, and pull the box toward you a bit. Take out the 4 slot screws on top and lift out the monovalve inside. Replace, and follow instructions in reverse. You're done.

Wish that had fixed my car's AC....

Whish the AC on the silver car hadn't died 30 miles into a 250 mile round trip today! Me and AC -- we're cursed!!!

Jeremy5848 · #51 07-03-2006, 10:39 PM

On my 1985 300D Turbo (California). I took off the heat shield that protects the battery (two screws above, two miserable ones below) although it isn't necessary, just makes things easier to get at. The rebuilding kit is about $50.

Jeremy

sunnyintx · #52 07-03-2006, 10:45 PM

Jeremy --

Don't know where you got your rebuild kit, but I got mine from JoeTLC (JT Outfitters) on eBay for about $20 each. Others have used these and had good results. I don't think my problem is related to the quality of the part.

http://stores.ebay.com/joetlc-com

hookedup4door · #53 07-04-2006, 01:56 PM

Would a weak compressor or one with low oil cause this warming/cooling fluctuation?

leathermang · #54 07-04-2006, 04:09 PM

A weak compressor would not usually be the culprit... that would usually just result in the compressor being on a larger percentage of the time... since it will cool at some times....
Too much oil can certainly be a problem...but short of burning out the compressor the oil is not needed for cooling... it is only in there for compressor lubrication...