Conventional wisdom is true on this one but its still odd... When the coolant is cold the car will be okay with no thermostat. Once its warmed up it'll over heat just like a stuck thermostat. Wierd but true.
-Curt Date: Sun, 29 Oct 2006 19:02:42 -0700 From: Craig McCluskey <[EMAIL PROTECTED]> Subject: [MBZ] Radiator flushing To: mercedes <[email protected]> Message-ID: <[EMAIL PROTECTED]> Content-Type: text/plain; charset=US-ASCII Seems to be the project of the day ... Anyway, I've set about to use the 5 pounds of citric acid I purchase awhile back and have been de-oiling and descaling the cooling system of our 617.912 W123. Yesterday, I drained the antifreeze, put in an ond thermostat that didn't close entirely and filled with water and two cups of Cascasde dishwasher detergent. By blocking the radiator with cardboard, I was able to bring the temp up to 100 C, let it run awhile -- noticing the flow through the fill -- and drain. Repeated with clean water to get the detergent out. Today, I put in 4.5 cups (at 120 g/cup) of citric acid and water and ran it. I found out that citric acid kills thermostats, because it did NOT open and I did not see coolant flow throught the fill. Hmmm ... So I went to force the thermostat permanently open, ala Jim Cathey and his .38 cartridge brass, but I didn't have any cartridge brass. I then reread the first couple of paragraphs of the de-oiling and descaling procedure in the engine manual. Guess what: It says to REMOVE the thermostat. I looked in vain for the section that lists the "shop made tool" of a forced-open thermostat I know I've seen somewhere. I couldn't find it. So, in order to turn the car around, I put the thermostat housing back on without the thermostat (but with the gasket). Guess what: There IS coolant flow through the radiator with the thermostat removed. Almost as much as when I had the thermostat in yesterday. And certainly a whole bunch more than with the dead thermostat in place. So, the conventional wisdom seems to have been thrown out the window. I was really suprised to read the engine manual saying to REMOVE the thermostat, but I'll still try to generate a forced-open thermostat. Craig --------------------------------- Want to start your own business? Learn how on Yahoo! Small Business. From [EMAIL PROTECTED] Mon Oct 30 14:13:41 2006 Received: from postal.windwireless.net ([199.164.167.12] helo=windwireless.net) by server8.arterytc8.net with esmtp (Exim 4.52) id 1GeXtV-0003AX-5n for [email protected]; Mon, 30 Oct 2006 14:13:41 +0000 Received: from windwireless.net (unverified [206.63.94.197]) by windwireless.net (WindPostal) with ESMTP id 388306 for multiple; Mon, 30 Oct 2006 06:17:26 -0800 Date: Mon, 30 Oct 2006 06:13:38 -0800 Content-Type: text/plain; charset=US-ASCII; format=flowed Mime-Version: 1.0 (Apple Message framework v553) From: Jim Cathey <[EMAIL PROTECTED]> To: [EMAIL PROTECTED], Mercedes Discussion List <[email protected]> Content-Transfer-Encoding: 7bit In-Reply-To: <[EMAIL PROTECTED]> Message-Id: <[EMAIL PROTECTED]> X-Mailer: Apple Mail (2.553) X-Server: High Performance Mail Server - http://surgemail.com r=-412260344 X-Info: aspam skipped due to (g_smite_skip) X-IP-stats: Incoming Last 1, First 34, in=195, out=0, spam=0 X-External-IP: 206.63.94.197 X-Antivirus-Scanner: Clean mail though you should still use an Antivirus Subject: Re: [MBZ] Next issue to sort out on rescued 79 240D X-BeenThere: [email protected] X-Mailman-Version: 2.1.9.cp1 Precedence: list Reply-To: Mercedes Discussion List <[email protected]> List-Id: Mercedes Discussion List <mercedes_okiebenz.com.okiebenz.com> List-Unsubscribe: <http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com>, <mailto:[EMAIL PROTECTED]> List-Archive: </pipermail/mercedes_okiebenz.com> List-Post: <mailto:[email protected]> List-Help: <mailto:[EMAIL PROTECTED]> List-Subscribe: <http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com>, <mailto:[EMAIL PROTECTED]> X-List-Received-Date: Mon, 30 Oct 2006 14:13:41 -0000 > So I was driving the 240D the other night and needed to turn on the > defroster (it has manual controls) and I detected the sweet smell of > coolant. I can't recall, but I seem to remember that the heater core > for > W123's is in a bad place, a place that's really hard to get to. The > coolant level hasn't plummeted since we've been driving the car so I'm > guessing the leak is small / minor. Sometimes you get lucky, and the leak is at the hose connections to the core. On some models gravity works to siphon small leaks inside where they can drip into the works. I don't know if the 123 is built this way, however. Worth looking on the firewall to see if there are any leaks there where the rubber meets the hard lines coming through the firewall. -- Jim
