Worst gas mileage since I owned the car.

[m3studio]

Ok, back again cause I STILL have not found my oil leak. Like I've said earlier, I changed valve-cover gaskets, OSV, all intake manifold gaskets, and throttle body gaskets. But whats getting me irritated is this mysterious vacuum leak. I have a CEL


Bank 1 Fuel Trim Additive Low


I'm thinking that it could be one of the o-rings from the fuel injectors came off? Remember that my little snap rings from the tip of the injector broke on a few injectors. I was told it was ok but thats something I'm going to check. But my symptoms are:


Humming sound. Hummings sound changes with rpms. If I pull the dip-stick, the humming gets louder. Comes from drivers side of the car. When I shut off the car, its the last noise I hear.


Today, I had a little less than half a tank and I am shocked how quick it went down. Ridiculous. I seriously watched it progressly drain.. Any ideas?

[Shak. G]

The last humming sound you hear will be air being sucked into the system as the pressure in the vacuum circuit equalizes. Basically there is a vacuum leak which you are aware of so i am just confirming that. I can't recall if the vacuum routing diagram is under the hood of the 740 I like it is for the 750. You need to meticulously trace that circuit all the hoses and check valves etc to find the defect. Or take it to the stealership.

[m3studio]

I'm thinking to do that. Im checking EVERYTHING right now.

Ok, found it to be a bad OSV. When I pull the dip-stick the humming changes blah blah.. Well I traced it. Holding the brake booster hose which connects to the back of the OSV, it vibrates and changes with the humming. So if humming changes the vibration changes with it. Removing and returning.

[Edwin NL]

Please just sell the damn car and buy the 3 series!!!!!

[m3studio]

Wooa relax, I'm not selling it. I started getting parts for my 6-speed conversion