When 1.9 is turned off, there is a buzzing noise, and then a brief hiss (sound of air being released). Is this normal?
One of my E36's does this every now and then but on mine it doesn't sound like it comes from the top of the engine, more like the firewall. I'm thinking it may be related to the vacuum system that opens and closes flaps in the HVAC system. I don't have any vacuum leaks or air leaks that I can detect, it only occurs after I shut the car off. It doesn't seem to effect the driveability and everything works so I have decided to just live with it. Do you have any issues with the car or any check engine lights or is it more a matter of curiosity?
Hi Dan, It's more than a curiosity. The car was removed from winter storage in May and began to act like it was being choked of air; or starved of fuel. I have checked all visible vacuum line connections, changed the fuel and air filters, and ran Techron through a tank of gas. Dry gas added as well. Car is better, but the problem does occur about 10 minutes into driving. On ocassion, it drives quite well for long periods of time. The idle seems like it could be a tad higher. My hiss-then-click sound comes from firewall area but I need a second person to isolate the location. You used an acronym - what is it? I have used the "search" function and come up with more ideas about fuel and air probs; both can be part of an electrical function. I also read about people who have diagnostics and change several parts only to find the CEL still lit. Do hope the forum can help me trouble shoot for a while. There are tons of threads that reveal the same problems/symptoms as I have. Searched "bad fuel" and found loads of similar stories. Any suggestions would be welcomed.
Sorry...HVAC...Heating Ventilation Air Conditioning. A lot of the doors and flaps under the dash that direct air to different vents are controlled by vacuum actuators. I get a hissing sound and sometimes a clunk after I shut the car off so I think one or more of the actuators may be getting weak but it's never affected the driveability. I guess if an actuator failed completely it could cause some issues and you would still get the hiss & click/clunk. Have the vacuum checked to be sure there's no leaks at low idle. It does sound like the idle control valve could be a possible culprit though.
My E-36 hisses as well now Hi Dan, My E36/8 is now hissing after shut off. did you ever locate the sourse of your problem? Thanks. Joehttp://stage.bmwcca.org/forum/images/smilies/confused.gif
No, I never have. To be honest though, it's one of those odd quirks (the E36 seems to have a LOT of those...?!) that doesn't seem to affect the driveability so it hasn't been high on the priority list. Somebody out there must have some kind of theory though?
