Oil leak from Cecil!

benfj180 · 16-07-2013, 09:29 PM

Hi guys,
Looking for a bit of advice re. leak. Couple of days ago I noticed a few drops no more the size than approx 4 no. 2p piece sized drips of oil (before you ask, yes defo oil, I checked, not trans fluid).
With the car on the ground could not see an awful lot other than the sump plug cover looking damp.
Got the car onto a family members ramp and started to investigate. The oil seems to be coming from the top of the engine, and in the most inconvenient place the back! A sensor, when looking the in the engine bay, just left of the rocker cover looks damp and potentially the seal between the rocker cover also looked a tad damp?
Are these places to start investigating and are they a nightmare job to do? What sensor is it? My oil level is still max after 3k miles of ownership so she is certainly not going dry.
Any advice is appreciated, cheers

Monkey · 16-07-2013, 11:10 PM

Hi, the sensor you mentioned sounds like the exhaust camshaft sensor. Never known these to leak.

The rocker cover gasket can leak if not fitted correctly after an inspection service (assuming that they have checked the valve clearances!), but they generally don't give an issue. Have you had a service recently?

The most common culprit in this area is the pressure valve on the block, under the bank 2 exhaust manifold.

http://www.realoem.com/bmw/showparts...88&hg=11&fg=10

number 10 on this picture. You can just about see it with the metal undershield on - there is a little cooling flap just behind the drain bung hole you can look up with a torch.

Might be worth just haveing a check again and see if it is that valve, if not & you confirm it is higher up then I would recommend taking the microfilter housing off so you can see with a telescopic mirror.

Regards
James

**cantfind1** · 17-07-2013, 04:15 AM

Yep pressure valve for sure!

NZ_M3 · 17-07-2013, 05:24 AM

From your description it doesn't sound like the CPV (although that is the one that tends to leak all the time) - The CPV sits on the top of the block near the head not the valve cover.
#10

What the CPV leak looks like:

Couple of possibilities by the sounds of your description:

#9 washer for the vent hose (if the cover's come off and someone hasn't put this back properly or with a new washer it can leak:

Another possibility (although unlikely) #19 (given you said it looks like it's coming from a sensor)

benfj180 · 17-07-2013, 08:45 AM

Hey thanks guys,

Thats great advice, ill have a double check tonight, but from what ive been reading on the net last night and the info you have given me, im now convinced it must be the CPV.

Cheers

Ben

16-07-2013, 09:29 PM	#1
benfj180 S3 - On the open road Join Date: Mar 2013 Posts: 114 Casino cash: $3139	Oil leak from Cecil! Hi guys, Looking for a bit of advice re. leak. Couple of days ago I noticed a few drops no more the size than approx 4 no. 2p piece sized drips of oil (before you ask, yes defo oil, I checked, not trans fluid). With the car on the ground could not see an awful lot other than the sump plug cover looking damp. Got the car onto a family members ramp and started to investigate. The oil seems to be coming from the top of the engine, and in the most inconvenient place the back! A sensor, when looking the in the engine bay, just left of the rocker cover looks damp and potentially the seal between the rocker cover also looked a tad damp? Are these places to start investigating and are they a nightmare job to do? What sensor is it? My oil level is still max after 3k miles of ownership so she is certainly not going dry. Any advice is appreciated, cheers

16-07-2013, 11:10 PM	#2
Monkey S5 - Full Throttle Join Date: May 2013 Location: Haywards Heath Posts: 266 Casino cash: $7387	Hi, the sensor you mentioned sounds like the exhaust camshaft sensor. Never known these to leak. The rocker cover gasket can leak if not fitted correctly after an inspection service (assuming that they have checked the valve clearances!), but they generally don't give an issue. Have you had a service recently? The most common culprit in this area is the pressure valve on the block, under the bank 2 exhaust manifold. http://www.realoem.com/bmw/showparts...88&hg=11&fg=10 number 10 on this picture. You can just about see it with the metal undershield on - there is a little cooling flap just behind the drain bung hole you can look up with a torch. Might be worth just haveing a check again and see if it is that valve, if not & you confirm it is higher up then I would recommend taking the microfilter housing off so you can see with a telescopic mirror. Regards James

17-07-2013, 04:15 AM	#3
cantfind1 S5, Sport Off, DSC M-track Join Date: Oct 2009 Location: Sydney Australia Posts: 675 Casino cash: $6490	Yep pressure valve for sure!

17-07-2013, 05:24 AM	#4
NZ_M3 S5, Sport On, DSC M-track Join Date: Jun 2008 Location: Auckland, New Zealand Posts: 1,434 Casino cash: $13579	From your description it doesn't sound like the CPV (although that is the one that tends to leak all the time) - The CPV sits on the top of the block near the head not the valve cover. #10 What the CPV leak looks like: Couple of possibilities by the sounds of your description: #9 washer for the vent hose (if the cover's come off and someone hasn't put this back properly or with a new washer it can leak: Another possibility (although unlikely) #19 (given you said it looks like it's coming from a sensor)

17-07-2013, 08:45 AM	#5
benfj180 S3 - On the open road Join Date: Mar 2013 Posts: 114 Casino cash: $3139	Hey thanks guys, Thats great advice, ill have a double check tonight, but from what ive been reading on the net last night and the info you have given me, im now convinced it must be the CPV. Cheers Ben