[mike sevel]

E93, 66K miles. Indy sez I have excess vacuum at oil filler cap. Could be valve cover (no leaks) or crankcase breather/vent hose located between the valve cover and connection under the intake manifold. Part number 11157559528. I was thinking about replacing the hose as a PM. Cost is cheap $35 OEM or $52 OE. Can it be replaced without removing the manifold?

Mikey

[mweisdorfer]

Originally Posted by mike sevel

E93, 66K miles. Indy sez I have excess vacuum at oil filler cap. Could be valve cover (no leaks) or crankcase breather/vent hose located between the valve cover and connection under the intake manifold. Part number 11157559528. I was thinking about replacing the hose as a PM. Cost is cheap $35 OEM or $52 OE. Can it be replaced without removing the manifold?

Mikey

You should replace the hose/ valve & PCV valve every 50k. Excess crank case pressure from these parts failing can and will lead to Rear main seal & valve cover seals breaking.

You can get an upgraded PCV valve & cap at Rob Beck's.

[dpaul]

Originally Posted by mweisdorfer

You should replace the hose/ valve & PCV valve every 50k. Excess crank case pressure from these parts failing can and will lead to Rear main seal & valve cover seals breaking.

You can get an upgraded PCV valve & cap at Rob Beck's.

OP's complaint is excess vacuum, not excess pressure. In addition, he has a 328, presumably with N51 or N52 engine, not an N54, so Rob Beck can't do anything for him.

I have little experience with N51/52, never having owned one. However, excess vacuum seems unlikely to be caused by cracks in the valve cover or hoses, which would lead to too little crankcase vacuum, not too much.

Excess vacuum could be caused by PCV valve failure (it should close off at idle to prevent the full manifold vacuum from being applied to the crankcase). In some N5x models, the PCV is integrated into the valve cover and I believe is not available from BMW as a separate part. However, I think it is serviceable/replaceable with aftermarket pieces.

That said, hoses may also need replacement. As mweisdorfer points out, they do degrade over time.

To your original question, I don't know if intake manifold removal is necessary but I suspect it is not, if you have the valve cover integrated PCV valve

Hopefully someone with N52 experience will chime in here.

[mweisdorfer]

Originally Posted by dpaul

OP's complaint is excess vacuum, not excess pressure. In addition, he has a 328, presumably with N51 or N52 engine, not an N54, so Rob Beck can't do anything for him.

I have little experience with N51/52, never having owned one. However, excess vacuum seems unlikely to be caused by cracks in the valve cover or hoses, which would lead to too little crankcase vacuum, not too much.

Excess vacuum could be caused by PCV valve failure (it should close off at idle to prevent the full manifold vacuum from being applied to the crankcase). In some N5x models, the PCV is integrated into the valve cover and I believe is not available from BMW as a separate part. However, I think it is serviceable/replaceable with aftermarket pieces.

That said, hoses may also need replacement. As mweisdorfer points out, they do degrade over time.

To your original question, I don't know if intake manifold removal is necessary but I suspect it is not, if you have the valve cover integrated PCV valve

Hopefully someone with N52 experience will chime in here.

Sorry man didn't know you had an n52.

I think there is a crank case hose there that intertwines in the intake manifold.

I'm going off memory of my wife's BMW 08' X5 that had an n52.

Something like this might help you

https://www.fcpeuro.com/products/bmw..._D_BwE#fitment

[Efthreeoh]

Originally Posted by dpaul

OP's complaint is excess vacuum, not excess pressure. In addition, he has a 328, presumably with N51 or N52 engine, not an N54, so Rob Beck can't do anything for him.

I have little experience with N51/52, never having owned one. However, excess vacuum seems unlikely to be caused by cracks in the valve cover or hoses, which would lead to too little crankcase vacuum, not too much.

Excess vacuum could be caused by PCV valve failure (it should close off at idle to prevent the full manifold vacuum from being applied to the crankcase). In some N5x models, the PCV is integrated into the valve cover and I believe is not available from BMW as a separate part. However, I think it is serviceable/replaceable with aftermarket pieces.

That said, hoses may also need replacement. As mweisdorfer points out, they do degrade over time.

To your original question, I don't know if intake manifold removal is necessary but I suspect it is not, if you have the valve cover integrated PCV valve

Hopefully someone with N52 experience will chime in here.

Good analysis, but the N52 doesn't really generate manifold vacuum. The N52 uses a vacuum pump driven off the cam chain. Any vacuum testing should include consideration of the vacuum pump.

Not a flame...

[Efthreeoh]

OP, why is it not as simple as a new oil fill cap?

[dpaul]

Originally Posted by Efthreeoh

Good analysis, but the N52 doesn't really generate manifold vacuum. The N52 uses a vacuum pump driven off the cam chain. Any vacuum testing should include consideration of the vacuum pump.

Not a flame...

That's very interesting! In this case, since the complaint is too much vacuum, I'd guess the pump is not the issue.

I could have sworn I saw a vacuum line from the throttle body to the PCV valve assembly on the N52 I looked at relatively recently but perhaps that just controls the PCV valve to regulate the vacuum from the pump?

N54 has a vacuum pump also but doesn't use it for establishing negative pressure in the crankcase, just for the brake booster and running the turbo wastegate solenoids. The N54 PCV system is poorly engineered and is the source of many problems.

[djh2]

OP is this what is happening to your car?

(not my vid but one that helped me diagnose the issue I had)

Whistle and high suction on oil fill cap?

I had this happen to me, but intermittently. I was having rough idle and higher than average oil consumption, and I had at least one time where my valve cover showed these symptoms.

It is possible to replace the on-valvecover cap, I bought mine off eBay for about $10 shipped. It's a dremel/cut/pry job but it can be done in-place if you desire.

After replacement, my idle has gotten smoother and I'll see how the oil consumption goes in the next few months. I believe excess oil gets sucked into the intake through the crankcase breather & PCV system but I'm not an expert on that. (I have read that people find their intake manifold oily when this is happening)

[kpng]

I have a 2007 328i (N52 engine), oil was leaking from the valve cover and there was excess vacuum (it was sucking air when I opened the oil cap). Figured out was the CCV so I replaced the entire valve cover and very carefully unclipped the breather hose when I took it off.

The oil leak is fixed but the excess vacuum persist. I think that the breather hose may be broken but I cannot find a guide online to replace it. It there a simple way to replace it without having to remove the entire exhause manifold? Thanks.

[Rmtt]

Originally Posted by kpng

I have a 2007 328i (N52 engine), oil was leaking from the valve cover and there was excess vacuum (it was sucking air when I opened the oil cap). Figured out was the CCV so I replaced the entire valve cover and very carefully unclipped the breather hose when I took it off.

The oil leak is fixed but the excess vacuum persist. I think that the breather hose may be broken but I cannot find a guide online to replace it. It there a simple way to replace it without having to remove the entire exhause manifold? Thanks.

I have an N52, but my car is a 128I. Hose runs under the intake manifold. Unless you are very flexible, I don't see how you could replace it without pulling most of the manifold. When I installed my 3 stage Intake...just the way the connector plug was "clocked" made it a pain to get it to release.

It's the reason why a lot of people break the hose in the first place when changing the intake.

[kpng]

Originally Posted by Rmtt

I have an N52, but my car is a 128I. Hose runs under the intake manifold. Unless you are very flexible, I don't see how you could replace it without pulling most of the manifold. When I installed my 3 stage Intake...just the way the connector plug was "clocked" made it a pain to get it to release.

It's the reason why a lot of people break the hose in the first place when changing the intake.

Next question is, how easy or difficult it is to take the manifold out? Can I just unbolt it from the engine and move it a few inches out so that I can get a hand under there?

What a pain just to replace a hose, I'm already exhausted from the valve cover job.

[Rmtt]

Originally Posted by kpng

Next question is, how easy or difficult it is to take the manifold out? Can I just unbolt it from the engine and move it a few inches out so that I can get a hand under there?

What a pain just to replace a hose, I'm already exhausted from the valve cover job.

If you've done the VCG, the intake manifold will be a piece of cake. I've heard of people accessing the starter without completely removing the intake, so you may be able to get in there.

Swapping out my intake only took about 2 hours....but I took time to thoroughly clean out everything underneath.

I know desertman123 mentioned he had done a complete swap in 45 minutes.

[desertman123]

Originally Posted by kpng

Next question is, how easy or difficult it is to take the manifold out? Can I just unbolt it from the engine and move it a few inches out so that I can get a hand under there?

What a pain just to replace a hose, I'm already exhausted from the valve cover job.

Originally Posted by Rmtt

If you've done the VCG, the intake manifold will be a piece of cake. I've heard of people accessing the starter without completely removing the intake, so you may be able to get in there.

Swapping out my intake only took about 2 hours....but I took time to thoroughly clean out everything underneath.

I know desertman123 mentioned he had done a complete swap in 45 minutes.

Yup lol. The valve cover job is WAY harder than the intake manifold job. I went so quick for that because the job had already been done, I was just replacing the small DISA.

There are 2 torx screws on towards the bottom of the manifold that hold up that electrical/vacuum box, very awkward to get the screws in and out without dropping them.

The CCV hose connecting to around where the throttle body is, is pretty awkward to undo too, but if you use a flathead and push the clip from the side, then your hand goes in thru the front, you can get it.

Also I use a big, long flathead to push the lower CCV hose clip that faces the valve cover while using my other hand to push the top clip in. That's also a big pain but if you get the correct angle it works quickly.

[kpng]

Originally Posted by desertman123

Yup lol. The valve cover job is WAY harder than the intake manifold job. I went so quick for that because the job had already been done, I was just replacing the small DISA.

There are 2 torx screws on towards the bottom of the manifold that hold up that electrical/vacuum box, very awkward to get the screws in and out without dropping them.

The CCV hose connecting to around where the throttle body is, is pretty awkward to undo too, but if you use a flathead and push the clip from the side, then your hand goes in thru the front, you can get it.

Also I use a big, long flathead to push the lower CCV hose clip that faces the valve cover while using my other hand to push the top clip in. That's also a big pain but if you get the correct angle it works quickly.

Can you provide a step by step guide as to what to remove to gain access to the bolts/screws that hold the manifold? I am still not able to find a guide, preferably one with pictures.

I assume the air filter box and hoses need to come off, but what else before I can loosen the manifold and move it enough to get my hands on the crankcase vent hose clips? Do I need to disconnect all the electrical cables attached to the manifold also? Thanks.

[DanT81]

I just did my valve cover and crankcase breather hose last summer on my 2008 328i e90, oil leak and vacuum issue. the breather hose was the hardest part but you don't need to remove the manifold. You do have to remove the air box and alternator (new bolts as they're aluminum) and having someone left handed really helps to remove the clamps. you can reach your arm under the manifold and get to the 2 clips, keeping in mind they are fastened on to plastic as well so don't pry sideways.

[Rmtt]

Originally Posted by kpng

Can you provide a step by step guide as to what to remove to gain access to the bolts/screws that hold the manifold? I am still not able to find a guide, preferably one with pictures.

I assume the air filter box and hoses need to come off, but what else before I can loosen the manifold and move it enough to get my hands on the crankcase vent hose clips? Do I need to disconnect all the electrical cables attached to the manifold also? Thanks.

Have a look at this video. It's for replacing a starter...but same concept.

[desertman123]

Originally Posted by kpng

Can you provide a step by step guide as to what to remove to gain access to the bolts/screws that hold the manifold? I am still not able to find a guide, preferably one with pictures.

I assume the air filter box and hoses need to come off, but what else before I can loosen the manifold and move it enough to get my hands on the crankcase vent hose clips? Do I need to disconnect all the electrical cables attached to the manifold also? Thanks.

Unplug as many sensors as you can from the manifold, unplug the wire going into the oil filter housing. Remove airbox, throttle body and anything attached to those. Undo powersteering reservoir and move it towards the front of the car, out of the way. Take out all the bolts for manifold and begin removing it from the car, you'll see what's in the way next. You can move the manifold off its studs fairly early on in the job, so stuff some paper towels into the intake ports, and reach between the manifold and head to gain access to the backside DISA wire and PCV heater(?) plug, along with the CCV hose that connects there (if you have the newer N52K? style manifold and CCV system).

The difficult parts can't really be made easier, I have long lankey arms/hands so I'm at an advantage lol. You could have this job done in 15 minutes if the cumbersome parts weren't so... cumbersome.

Pic attached, it's the electrical/vacuum "distribution" box that connects to the bottom of the manifold. See all the wires leading into the area with the red box? I know it's not the best picture lol. You need to go at it with a T25 torx if I remember right, there are 2: front and rear.

Don't get too worried about labeling the wires. Obviously do it if you feel you need to, but everything only plugs into 1 sensor - each plug is uniquely shaped.

[nsjames]

pulling the intake is easy.

I've even reused the o rings *gasp* while changing my starter in a parking lot.

I replaced the crappy plastic hose from the back of the valve cover with rubber hydraulic hose.
It's much better for future service. You can cut the plastic hose right at the fittings cleanly and then what's left of the plastic quick connect fits a 3/4" hose perfectly.

but I'm not sure how that hose being damaged is going to cause excess crankcase vacuum. That hose being broken would vent the PCV system to atmosphere.

[kpng]

Originally Posted by nsjames

pulling the intake is easy.

I've even reused the o rings *gasp* while changing my starter in a parking lot.

I replaced the crappy plastic hose from the back of the valve cover with rubber hydraulic hose.
It's much better for future service. You can cut the plastic hose right at the fittings cleanly and then what's left of the plastic quick connect fits a 3/4" hose perfectly.

but I'm not sure how that hose being damaged is going to cause excess crankcase vacuum. That hose being broken would vent the PCV system to atmosphere.

So I managed to get the hose replaced, it was not too difficult. Thamk you everyone for their help and repair tips, they were really helpful and much appreciated. The hardest part was getting the damn hose off, ended up having to break the clips at the connector and then it came off.

How much vacuum is normal in the crankcase, there is some resistance when opening the oil cap but not something that I have to fight too much to get it open.Is this normal?

The car runs really smoothly now, no hesitation, no rough idle, and no more oil leaks. However the CEL is still one, I and showing 2 faults P0171 and P0174, and two pending P0171p and P0174p. What does this mean? Will they clear themselves? My cheapo OBD scanner is unable to erase any of the codes.

Thanks again.

[nsjames]

those are both codes for lean conditions.

they may go away if they were a result of the massive air leak at the manifold if your hose was cracked.

drive it for a while. see if it goes out.