W140 AC center vent valves cycling
Thread Starter
Junior Member
Joined: Jul 2012
Posts: 66
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From: Cape Canaveral, Fl
1999 S500 Grand Edition
W140 AC center vent valves cycling
I have a 1999 W140 S500 and when I accelerate, the center vent valves cycle closed and then open after a bit while operating the AC. The AC blows ice cold even in florida summer. Right now, it works otherwise but it is annoying. I can also feel the motor idling a little rough every now and again. I think that there it is a small vaccuum leak but I am not sure.
Anyone ever had this problem? Is this one of those $1000 labor for the $25 part things?
Thanks,
Mark
Anyone ever had this problem? Is this one of those $1000 labor for the $25 part things?
Thanks,
Mark
Thread Starter
Junior Member
Joined: Jul 2012
Posts: 66
Likes: 0
From: Cape Canaveral, Fl
1999 S500 Grand Edition
Thread Starter
Junior Member
Joined: Jul 2012
Posts: 66
Likes: 0
From: Cape Canaveral, Fl
1999 S500 Grand Edition
I got the car back today.
The motor does not provide vacuum. The AC Vents are worked with vaccum supplied by the PSE Pump under the back seat. The pump is providing the vacuum, but there was a leak in one of the lines going to the passenger front seat. I had them cap off the line and all is well again.
It is the rough equivalent of flipping the garbage disposal switch and the garage door opening. Go figure.
The motor does not provide vacuum. The AC Vents are worked with vaccum supplied by the PSE Pump under the back seat. The pump is providing the vacuum, but there was a leak in one of the lines going to the passenger front seat. I had them cap off the line and all is well again.
It is the rough equivalent of flipping the garbage disposal switch and the garage door opening. Go figure.
