How to measure BMW crankcase pressure

Damon Technician Macclenny, Florida Posted   Latest   Edited  
Question
Drivetrain
2006 BMW X5 3.0i 3.0L (M54) 5-spd (5L40-E)

This is my first post as a member. I am trying to diagnose a smoking BMW x5. I am using my WPS500x to measure crankcase pressure and the instructions from a BMW tsb say to use a special adapter on the oil fill hole. I do not have a special adapter and cannot make anything to fit and seal. I used the dipstick tube to take the measurement. Is this acceptable and will I get an accurate reading using the dipstick tube?

I measured -35mBar at idle. The TSB I am referring to gives a specification of 16mBar for this M54 engine. I am assuming they mean 16mBar of vacuum.

We see very few BMWs here and I want to know if I am going about this properly. I suspect a failed crankcase pressure control valve.

0
Brandon Technician
Medina, Minnesota
Brandon Default
   

I've never used a WPS to measure crankcase pressure, I don't think it is accurate enough at such a low pressure. You're best bet is to use a digital manometer like the Pyle PDMM01 or similar and modify an oil cap to accept an NPT nipple. Modified Audi and BMW oil caps: diag​.​net/file/f65oe5pmw…

Underside of BMW…

+2 Default Ð Bounty Awarded
Philip Technician
Eaton Socon, United Kingdom
Philip Default
   

Have you watched the Autologic BMW Mini cam cover video as they have issues on sealing. Have just brought a oil filler cap from Mini to modify for testing with WPS 500. Might have to use the brass adapter to get a tight fitting. We have also brought a selection of smoke machine bugs for blanking dipstick. There is 2 waveform on the library on crank case pressure from a BMW X5 good and…

+1 Default Ð Bounty Awarded
Jose Technician
Woodland, California
Jose Default
   

I have a snap -on oil funnel set manufactured by AST. It comes with an assortment of oil cap adaptors. i have a hose that fits the inside diameter and that is what i use

0 Default Ð Bounty Awarded
Ray Diagnostician
North York, Ontario
Ray Default
   

These captures are from an 06 BMW 330xi 3.0 and I used an oil filler adapter with the WPS500. 14 in H20 is 14 inches of water column. The fuel filler adapter on the right is the one that I use in place of the engine oil cap. Go to AESwave​.​com and the adapter number is SW-GLD034

0 Default Ð Bounty Awarded
Joe Diagnostician
Midland, Texas
Joe Default
 

Hello I read an article from motorage written by Scott mana it’s titled “living in a crankcase vacuum“ It’s a very informative article. searchautoparts​.​com/motorage/under…

+1 Default Ð Bounty Awarded
Victor Technician
Cudahy, California
Victor Default
 

hi, about that post. I took a look at that article and I would say is not entirely correct, it is theoretically correct... but in a real world it might misleading you. ( specially in his BMW testings.) never follow ISTA to diag fuel mixture issue, unless you are lecturing yourself, it will take you to the moon... instead use obd2 data and mode6.

+1 Default Ð Bounty Awarded
Joe Diagnostician
Midland, Texas
Joe Default
 

Thank you for the knowledge victor I had no idea Bernoulli came out with bar to get rid of the positive and negative reading so when you read a # on your manometer it is absolute ? I have the same Dwyer manometer.

0 Default Ð Bounty Awarded
Bill Owner/Technician
Jackson, Michigan
Bill Default
 

Damon -17 mbar is my know good spec on this engine code (m54) you can use the dipstick tube its a pretty close comparison although the oil fill cap is what most suggest. Your WPS500 is more than capable to measure this. I personally use a digital manometer like Brandon L shows mainly cause its quick to hook up and get a reading. Sell all the attaching hoses to the control valve as well…

0 Default Ð Bounty Awarded
Damon Technician
Macclenny, Florida
Damon Update
 

Thank you all for your input and suggestions. I will have to invest in some adapters very shortly.

0 Update Ð Bounty Awarded
Jose Technician
Woodland, California
Jose Default
 

You have a lean code? Do you have any fuel trim scan data? Its usually nice when you can perform various tests that all point to the same problem

0 Default Ð Bounty Awarded
Damon Technician
Macclenny, Florida
Damon Default
 

There were several DTCs present. The customer's only concern is the smoking. I was starting with a crankcase pressure test as the crankcase vent valve is the most common cause of smoking from oil. Once I condemn or eliminate this vent valve I will start diagnosing DTCs.

0 Default Ð Bounty Awarded
Ray Diagnostician
North York, Ontario
Ray Default
 

Here are some crankcase vacuum specs by Ceferino Gonzales.

0 Default Ð Bounty Awarded
Michael Owner/Technician
Tampa, Florida
Michael Default
 

Usually when the diaphragm breaks in the crank case vent valve there is a lot of vacuum at the oil fill cap. With the car running, remove the cap, if it's hard to lift up and there is a big inrush of air then the valve is bad. If not look for other vacuum leaks in the air boot/intake area. mike

0 Default Ð Bounty Awarded
Victor Technician
Cudahy, California
Victor Default
   

wow.... that is a very expensive CC pressure readings for that I have used for more than 15 yrs a tool that cost $95.00 check my pic. and it takes 1 min job. ok. what was the eng coolant temp, rpm and engine load? what is the scan tool saying about fuel mixture. STFT? oh... extra Comment: Bernoulli came out with unit of measure (bar) to get rid of the negative or positive english imperfect…

0 Default Ð Bounty Awarded
Ray Diagnostician
North York, Ontario
Ray Default
 

With one or more low compression cylinders, a pressure transducer on a dipstick tube can quickly find WHICH cylinder or cylinders has excessive blow-by gases blowing past the piston rings into the crankcase, without removing the upper intake manifold to do cylinder leakage tests. In this capture, the green channel is the starter amps showing high and low compression cylinders. The yellow…

+3 Default Ð Bounty Awarded
Damon Technician
Macclenny, Florida
Damon Resolution
 

Today I installed the crankcase vent valve and all associated hoses with genuine BMW parts. After a test drive I remeasured crankcase pressure at the oil fill hole with the special adapter I made for my WPS500x. It measured 16 mBar of vacuum, exactly what the spec is for this engine. It also totally stopped smoking, which was the original complaint. Thank you all for your…

+1 Resolution Ð Bounty Awarded