Hi All, I have an 87 190e 2.3 and have noticed a loud ticking sound coming from the vave cover. It goes away at 2000 rpm. How can I tell which valve is the culprit?
Also the dreaded climate control!! Blows hot air out the side vents all the time. Is there a way to test the pushbutton unit before just purchasing a new one? Last summer it stopped working when the aux water pump died- so I extracted the pump but it still did not work properly. Is it possible that the malfunctioning pump killed the pushbutton unit?
Thanks in advance!!
Charles Markham
1987 190E 2.3 70k

The pump could have killed the pushbuttons. The other thing that will render one inop is the lack of vacuum. Check under the hood near the fuse box and make sure that there is vacuum there.

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Benzmac:
Donnie Drummonds
1992 500E (very soon I hope :)
1981 280GE SWB
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

xander,

The aux pump knocking out the PB unit is so common that the rebuilders of the PB units won't warranty their unit when you don't replace the aux pump. The aux pump is easy to check by checking current draw. I'm not sure about a 190, but the one on a 300E should not draw more 1.3 Amps.

Good luck,

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Larry Bible
'84 Euro 240D, 523K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

Does the auxillary water pump have to be replaced? I took mine out a long time ago and hve no intentions of putting it back. The heat works fine without it and the car does not overheat.
Charles
1987 190E 2.3

I don't think it would HAVE to be replaced. If it's not there, it won't blow the new climate control unit. But it's always best to have everything put back the way it was designed, in spite of the fact that climate control is not one MB's strong suits from a design point.

Good luck,


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Larry Bible
'84 Euro 240D, 523K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles