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Discussion Starter #1
Did a smoke test and this was the only leak I found well because it’s obvious some kind of hose is missing I just don’t know enough to know this hose goes and connects to please help

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It's not suppose to leak during a smoke test. Some years have a vacuum hose that goes back to the intake. That's the Crankcase vent, I've heard different things about getting just the diaphragm or having to buy the entire valve cover. I've always replaced the entire valve cover.
 

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It's not suppose to leak during a smoke test. Some years have a vacuum hose that goes back to the intake. That's the Crankcase vent, I've heard different things about getting just the diaphragm or having to buy the entire valve cover. I've always replaced the entire valve cover.
The crank case vent can be re-circulated into the intake system or it can be vented into atmosphere. The latter is better for the engine but worse to the environment.
 

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I'm confused, what are you trying to say?
Exactly what you said. Some years have a hose that leads fumes back into intake. That's mainly for strict emissions forced by some states and provinces. If you install a membrane and vent it into atmosphere, which I think is the case here (no crank case hose), it'll run just fine but will pollute the atmosphere. Worse thing that could happen is the gas not being able to escape the crank case and in turn creating sludge and major issues.
 

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So is air or the smoke supposed to come out of there when I did a smoke test on it since it’s a vent?


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Yes, there is a spring and a membrane that seals the unit when there is no blow-by gasses present or if the amount of blow-by gasses has not built up enough pressure. The vent valve opens only under certain pressure to release blow-by gasses. So, if you did a smoke test and put pressure in the system, you will see smoke come out of there.
 

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Yes, there is a spring and a membrane that seals the unit when there is no blow-by gasses present or if the amount of blow-by gasses has not built up enough pressure. The vent valve opens only under certain pressure to release blow-by gasses. So, if you did a smoke test and put pressure in the system, you will see smoke come out of there.
In my experience this is not correct.
 

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I hate to be a know-it-all, but I've had a couple of these engines and learned a fair bit about the crankcase venting system... The BMW crankcase vent system is not a typical one that vents under pressure as was described in this thread. The BMW system keeps the crankcase operates under a small amount of vacuum. The thing you have identified as leaking contains a spring and orange rubber diaphragm that serves to compare vacuum pressure to atmospheric pressure - which prevents the system putting the crankcase under too much vacuum. Very early versions did connect the port to the intake (before the throttle), but it was completely redundant and removed on later production engines and retrospectively when under repair.

Over time the orange rubber diaphragm splits, and no longer regulates vacuum pressure in the crankcase. Once the rubber diaphragm splits, outside air freely enters through the split diaphragm, into the crankcase, and eventually back to the intake under vacuum - symptoms are a vacuum leak and sometimes increased oil consumption.

It's an easy fix. There is a CCV Valve repair kit available from BMW that contains a new spring, rubber diaphragm, and black cap. Replace the lot on both valve covers and rest easy for a few more years. Another common vacuum leak point is the CCV vent pipes that connect the valve covers to the intake manifold (after the throttle valve). I usually fit two new CCV valve repair kits and and pipes as preventative maintenance. The system layout changed through the years, but is easily brought up to the latest version - there is a TSB floating around on the web that describes the needful.
 

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Aaand I just realised you have a normally aspirated I6 instead of a V8 - the system operating principles are exactly the same, but I think a new valve cover is required for your engine as the parts don't come seperately on that engine.
 

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i hate to be a know-it-all, but i've had a couple of these engines and learned a fair bit about the crankcase venting system... The bmw crankcase vent system is not a typical one that vents under pressure as was described in this thread. The bmw system keeps the crankcase operates under a small amount of vacuum. The thing you have identified as leaking contains a spring and orange rubber diaphragm that serves to compare vacuum pressure to atmospheric pressure - which prevents the system putting the crankcase under too much vacuum. Very early versions did connect the port to the intake (before the throttle), but it was completely redundant and removed on later production engines and retrospectively when under repair.

Over time the orange rubber diaphragm splits, and no longer regulates vacuum pressure in the crankcase. Once the rubber diaphragm splits, outside air freely enters through the split diaphragm, into the crankcase, and eventually back to the intake under vacuum - symptoms are a vacuum leak and sometimes increased oil consumption.

It's an easy fix. There is a ccv valve repair kit available from bmw that contains a new spring, rubber diaphragm, and black cap. Replace the lot on both valve covers and rest easy for a few more years. Another common vacuum leak point is the ccv vent pipes that connect the valve covers to the intake manifold (after the throttle valve). I usually fit two new ccv valve repair kits and and pipes as preventative maintenance. The system layout changed through the years, but is easily brought up to the latest version - there is a tsb floating around on the web that describes the needful.
+1
 

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I hate to be a know-it-all, but I've had a couple of these engines and learned a fair bit about the crankcase venting system... The BMW crankcase vent system is not a typical one that vents under pressure as was described in this thread. The BMW system keeps the crankcase operates under a small amount of vacuum. The thing you have identified as leaking contains a spring and orange rubber diaphragm that serves to compare vacuum pressure to atmospheric pressure - which prevents the system putting the crankcase under too much vacuum. Very early versions did connect the port to the intake (before the throttle), but it was completely redundant and removed on later production engines and retrospectively when under repair.

Over time the orange rubber diaphragm splits, and no longer regulates vacuum pressure in the crankcase. Once the rubber diaphragm splits, outside air freely enters through the split diaphragm, into the crankcase, and eventually back to the intake under vacuum - symptoms are a vacuum leak and sometimes increased oil consumption.

It's an easy fix. There is a CCV Valve repair kit available from BMW that contains a new spring, rubber diaphragm, and black cap. Replace the lot on both valve covers and rest easy for a few more years. Another common vacuum leak point is the CCV vent pipes that connect the valve covers to the intake manifold (after the throttle valve). I usually fit two new CCV valve repair kits and and pipes as preventative maintenance. The system layout changed through the years, but is easily brought up to the latest version - there is a TSB floating around on the web that describes the needful.
My apologies for misinformation.
 

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Discussion Starter #17
I hate to be a know-it-all, but I've had a couple of these engines and learned a fair bit about the crankcase venting system... The BMW crankcase vent system is not a typical one that vents under pressure as was described in this thread. The BMW system keeps the crankcase operates under a small amount of vacuum. The thing you have identified as leaking contains a spring and orange rubber diaphragm that serves to compare vacuum pressure to atmospheric pressure - which prevents the system putting the crankcase under too much vacuum. Very early versions did connect the port to the intake (before the throttle), but it was completely redundant and removed on later production engines and retrospectively when under repair.

Over time the orange rubber diaphragm splits, and no longer regulates vacuum pressure in the crankcase. Once the rubber diaphragm splits, outside air freely enters through the split diaphragm, into the crankcase, and eventually back to the intake under vacuum - symptoms are a vacuum leak and sometimes increased oil consumption.

It's an easy fix. There is a CCV Valve repair kit available from BMW that contains a new spring, rubber diaphragm, and black cap. Replace the lot on both valve covers and rest easy for a few more years. Another common vacuum leak point is the CCV vent pipes that connect the valve covers to the intake manifold (after the throttle valve). I usually fit two new CCV valve repair kits and and pipes as preventative maintenance. The system layout changed through the years, but is easily brought up to the latest version - there is a TSB floating around on the web that describes the needful.


Thank you so much for all the information!


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Discussion Starter #18
I hate to be a know-it-all, but I've had a couple of these engines and learned a fair bit about the crankcase venting system... The BMW crankcase vent system is not a typical one that vents under pressure as was described in this thread. The BMW system keeps the crankcase operates under a small amount of vacuum. The thing you have identified as leaking contains a spring and orange rubber diaphragm that serves to compare vacuum pressure to atmospheric pressure - which prevents the system putting the crankcase under too much vacuum. Very early versions did connect the port to the intake (before the throttle), but it was completely redundant and removed on later production engines and retrospectively when under repair.

Over time the orange rubber diaphragm splits, and no longer regulates vacuum pressure in the crankcase. Once the rubber diaphragm splits, outside air freely enters through the split diaphragm, into the crankcase, and eventually back to the intake under vacuum - symptoms are a vacuum leak and sometimes increased oil consumption.

It's an easy fix. There is a CCV Valve repair kit available from BMW that contains a new spring, rubber diaphragm, and black cap. Replace the lot on both valve covers and rest easy for a few more years. Another common vacuum leak point is the CCV vent pipes that connect the valve covers to the intake manifold (after the throttle valve). I usually fit two new CCV valve repair kits and and pipes as preventative maintenance. The system layout changed through the years, but is easily brought up to the latest version - there is a TSB floating around on the web that describes the needful.


Any advise on removing it?
Everyone I see on YouTube has to use a dremel to remove it


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