Joined: 19 Jul 2002
Location: NC State University
|Posted: Tue Apr 16, 2013 8:06 am Post subject: temp gauge and heater
I haven't posted in a while because the old '85 325e is going strong, save for two nagging problems:
1. The engine temp gauge reads low and is jumpy. I thought the problem was the sender, so I replaced it. No change. Then I thought it was the thermostat because the output from the heater is low, so I replaced it. No change. Then I thought a bad connection, so I cleaned the ground connection under the dash and the connection on the gauge itself after pulling the cluster. No change. OK, I need some suggestions....bad solder joint on the printed circuit board in the cluster? Bad gauge itself?
2. Second, and I think unrelated problem, is low heater output. Changing the thermostat did no good. Thought maybe there was an air pocket in the heater, so I bled the system. Front end on ramps, fast idle, opened bleed screw. Bled for a good 15 minutes with varying engine speed. Couldn't tell if any air was expelled...the stream looked steady. While the heat output seemed a little better, it still feels cool to me. Could it be that the heater control valve isn't opening fully? It is 28 years old after all. I will drive the car for a week or so and bleed again. Any other suggestions? If it is the valve, it is NLA...suggestions?
Thank you in advance,
'85 325e, born October 1984
220K miles, original owner