shogun
01-04-2013, 07:45 AM
Replacing the idle valve on an M50 is a very difficult job, not complicated, but awkward.
First, remove the air box by loosening the hose clamp on the bellows, and loosening the two 10 mm nuts holding it to the inner fender, no need to remove the nuts, just loosen them. If you have cruise control, lift the cruise actuator off of the studs and then lift the air box up , remove the 10 mm bolt holding the sensor into the rear of the air box and unplug the Air Flow Meter. Lift the air box up and out of the car.
Remove the hose clamp from the other end of the bellows, pull the bellows off of the throttle housing and pull the idle hose out from the bellows. Unplug the Throttle Position Sensor , gently remove the ASC cable from the throttle housing, if you have it and remove the 4 10 mm bolts holding the throttle housing onto the intake manifold. There is no need to remove the throttle cables, just move the housing out of the way.
Next , remove the cap from the oil filter housing, and remove the oil filter. Cover the housing with a clean rag to prevent foreign material entering. You can now reach in under the manifold from the front with one hand and the side with the other. You will need to watch through the small holes in the top of the manifold to see what you are doing.
In the hole left by the throttle housing, you will see the outlet pipe of the idle valve. This fitting is clipped into the manifold with a very fragile plastic clip. A smart move would be to buy a new fitting when you get the idle valve, it only costs a couple of dollars and makes a lot of sense to replace it at the same time. You can unclip the fitting through the hole in the manifold and pull it away from its mount. Pull the other end of this hose off the idle control valve. Now push the valve toward the firewall until it comes out from the rubber bracket that secures it. It is best not to remove this rubber loop from its mount as it can be very awkward to put it back in. Now that you have the valve loose, you can raise it to gain access to the inlet hose. If there is no clamp on it, you can remove it there and then, if it has a hose clamp on it, you may find it easier to remove the valve and hose together. The hose is the same one you removed from the intake bellows earlier, you can feed it through, under the manifold , as you pull the valve out over the oil filter housing.
When installing the new valve, take great care to get the hoses on all the way, if the intake hose goes on easily, put a clamp on it. Make especially sure the outlet pipe is correctly attached to the valve, and it's fitting is properly seated in the manifold. A new fitting comes with a new O ring already fitted, you will hear it snap into place when it is located correctly. If this hose comes off, it will cause stalling at idle, even backfiring, and a very rough running engine.
Feed the inlet house back through under the manifold until the valve is back in place, push it back into the rubber loop , and then put the outlet hose onto the valve. The outlet hose is not very pliable so it is best not to try and force the entire assembly under the manifold. Put it on last.
source: Koala Motorsport Inc.* North East Ohio's ONLY Exclusive BMW Independent (http://koalamotorsport.com)
First, remove the air box by loosening the hose clamp on the bellows, and loosening the two 10 mm nuts holding it to the inner fender, no need to remove the nuts, just loosen them. If you have cruise control, lift the cruise actuator off of the studs and then lift the air box up , remove the 10 mm bolt holding the sensor into the rear of the air box and unplug the Air Flow Meter. Lift the air box up and out of the car.
Remove the hose clamp from the other end of the bellows, pull the bellows off of the throttle housing and pull the idle hose out from the bellows. Unplug the Throttle Position Sensor , gently remove the ASC cable from the throttle housing, if you have it and remove the 4 10 mm bolts holding the throttle housing onto the intake manifold. There is no need to remove the throttle cables, just move the housing out of the way.
Next , remove the cap from the oil filter housing, and remove the oil filter. Cover the housing with a clean rag to prevent foreign material entering. You can now reach in under the manifold from the front with one hand and the side with the other. You will need to watch through the small holes in the top of the manifold to see what you are doing.
In the hole left by the throttle housing, you will see the outlet pipe of the idle valve. This fitting is clipped into the manifold with a very fragile plastic clip. A smart move would be to buy a new fitting when you get the idle valve, it only costs a couple of dollars and makes a lot of sense to replace it at the same time. You can unclip the fitting through the hole in the manifold and pull it away from its mount. Pull the other end of this hose off the idle control valve. Now push the valve toward the firewall until it comes out from the rubber bracket that secures it. It is best not to remove this rubber loop from its mount as it can be very awkward to put it back in. Now that you have the valve loose, you can raise it to gain access to the inlet hose. If there is no clamp on it, you can remove it there and then, if it has a hose clamp on it, you may find it easier to remove the valve and hose together. The hose is the same one you removed from the intake bellows earlier, you can feed it through, under the manifold , as you pull the valve out over the oil filter housing.
When installing the new valve, take great care to get the hoses on all the way, if the intake hose goes on easily, put a clamp on it. Make especially sure the outlet pipe is correctly attached to the valve, and it's fitting is properly seated in the manifold. A new fitting comes with a new O ring already fitted, you will hear it snap into place when it is located correctly. If this hose comes off, it will cause stalling at idle, even backfiring, and a very rough running engine.
Feed the inlet house back through under the manifold until the valve is back in place, push it back into the rubber loop , and then put the outlet hose onto the valve. The outlet hose is not very pliable so it is best not to try and force the entire assembly under the manifold. Put it on last.
source: Koala Motorsport Inc.* North East Ohio's ONLY Exclusive BMW Independent (http://koalamotorsport.com)