Thanks all. I write the reply using ">>>". The general consensus is to check the sensor(s).
OK Don wrote: <rest snip> Your situation isn't exactly like mine, and I have no idea how the 190E is wired, but I'd be looking for miss-wired or bad sensors - there are several that are meant to prevent engine over-heating by turning the AC off. I think yours is reacting to sensor input, not a bad controller. >>> I check the sensor input. Thanks. Craig McCluskey wrote: Does it not run well on regular? If both the owner's manual and filler flap say it should, something is wrong. Unfortunately, I cannot tell you what. >>> Owner's manual says premium gas. Never tried on regular. I did tried >>> running regular in a full tank on my '99 E320 4matic which requires >>> premium. But, I consumed all on the highway Rt 80 in PA and portion of >>> OH. And then immediately fill it with premium. No pings or lost of >>> power on the 360 miles ride. This was done at night when the traffic is >>> less and cooler. Donald Snook wrote: Is it possible that you put too much R12 in it? I think there is a sensor on the high pressure line and when the pressure gets too high (which it might when the temperature gets higher), the compressor shuts off. I would check the pressures (assuming you have gauges) and the pressures could be too high or the sensor might be bad. Is it cycling all the time? >>> I had it measure, 2 lbs and 4ozs exactly stated on the front.. Yes, it >>> cycles all the time when cold. Thanks. Peter Frederick wrote: There is nothing wrong with AC, you have an engine running too hot problem. The AC will be shut off when the aux fan comes on due to excessive heat, and your main cooling fan is not working correctly -- you should NEVER see 100C with normal operation. You will have to find out why you are running too hot. Could be a bad thermostat, a bad radiator, a failed main fan clutch (they are electric on the 190, I think). You also need to check the condition of the fuel injection system, particularly the status of the rubber hoses and the boot between the fuel distributor air meter horn and the throttle body. I suspect you have serious leaks, causing persistent lean running and hence knocking on regular. You will also need to check the distributor, as I don't remember if there is a mechanical advance in there (unlikely, but check, it could be stuck) You should be running at about 80C unless you are stuck in traffic and it's over 110F with 80% RH with a good cooling system. I would also replace the ACC temp sensor, it could be bad as the AC should come back on when the temp goes down. >>> Both thermostat and radiator replace less than a year ago. Fan turning >>> so I think the main fan clutch is working fine. Will check the rubber >>> hoses. Also will check the ACC temp sensor. I am running premium gas >>> and did not hear any knocking or pinging. Thanks. ----- Original Message ----- From: "hursley" <[EMAIL PROTECTED]> To: "Mercedes Discussion List" <mercedes@okiebenz.com> Sent: Saturday, April 19, 2008 3:29 PM Subject: [MBZ] 190E 2.3 a/c issue > List, > > I like to get your infinite wisdom on the air condition issue. > > Vehicle is '93, automatic and uses preimum gas (ouch). Not regular as > stated in the owner's manual and filler flap. > > When the car is cold (meaning, the temperature in the coolant as from the > guage is at or below 40C) and a/c comes up fine. > > While driving down the road, the coolant temperature increase to 100C and > then the a/c turns off. That is, when the temperature rise to say 1XX the > a/c controller unit will shut the a/c down. It is suppose to wait for it > to cool back down to 1YY and then kick the a/c. Mine did not and had to > endure the whole journey in a "cook" car. > > When the car is cool down after driving, say the engine coolant > temperature is below 80C, the a/c works immediately when started. But > when it is above 80C, the a/c will not engage. And if it works then > during driving, when it hits 100C, a/c is off. > > There is plenty of R12 in the system else the a/c will not produce cool > air. There is no leak, and if so there will be no cool air when engine is > started. The ambient temperature is in the high 70'sF. Somehow, we did > not experience spring, winter is very mild, and summer is here already in > josey (NJ). Birds are singing, flowers and tree pollens everywhere. And > I am sneezing every few minutes. > > So, what do you guys think on the a/c? Is there a way to test the unit? > > I am just guessing that the controller unit is faulty as it closes when > hot and never opens when cool. If this is right, I will be calling Rusty > for parts. > > Thanks in advance. > > K.S. > _______________________________________ > http://www.okiebenz.com > For new parts see official list sponsor: http://www.buymbparts.com/ > For used parts email [EMAIL PROTECTED] > > To Unsubscribe or change delivery options go to: > http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com _______________________________________ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
