M318is - zn
New member
Hi Guys,
Our E90's Vacuum pump seal is leaking and i'll be giving it a DIY this weekend.
Found this useful thread that can hopefully help someone else with the same issue, instead of bmw charging the earth for a new pump.
E90 N46 Vacuum Pump removal, repair and reinstatement guide
As there does not seem to be a guide for this anywhere I did the repair today and thought I would post my experience to try and help anyone else attempting this in the future.
There are lots of suggestions that using gasket sealer is a short term fix, this guide uses the installation of two new seals to provide a permenant repair and hopefuly save you the agro of repeating the process ever again, trust me once is enough You will also not need to remove the rocker cover gasket to complete this repair despite what I was told by BMW and two indys I consulted.
The best quote I got for this repair was from an indy in Sheffield, £360 for a new Vacuum Pump, £80 for a Valve Cover Gasket, £200 6 hours of labor - Total Indy £640. Total cost for DIY £8.49
Symptoms:
Intermittent smell of burning oil blown through the air vents into the cabin
Brief plumes of white smoke from under the bonnet
Tickover RPM's fluctuation (Searching between 500-700rpm)
Loosing oil
Fault:
Brake Vacuum pump main seal leaking
Brake Vacumm pump O ring leaking
Required:
E90 Engine oil filter with seals
O ring (Part number 11667509080)
Procedure:
1> Remove the two plastic covers at the far side of the cabin micro filter housing
2> Unclip and remove the cable carrier
3> Remove the 7 x 8mm bolts holding the cabin microfilter housing in place and then remove the housing
4> Once the above is removed you can remove the two strut barces. Torx bolts hold the far ends on place. The centre bolt is found under a plastic circular cover (5). Pop it out with a screw driver and remove the bolt. The strut braces then slide straight out.
6> Remove the cabin micro filter under tray.
You now have fairly good access to the engine but the Vacuum Pump is still not visible. To access the Vacuum Pump remove the plastic cover from the top of the engine. Just lift up and pull, it comes away easily.
With the platic engine cover off you can now see the vacuum pump.
Its right up against the bulkhead of the car and the three 10mm retaining bolts can only be located by sliding your hand behind and feeling for them. Be under no doubt, there is about 40mm of space between the pump and the bulk head, its fiddly, frustrating and awkward.
Use a quarter drive with a 10mm socket to remove the three bolts.
The vacuum pump will then slide straight out. Just as it pulls out, take a photograph of the locator position, this is the part of the pump which connects to the cam driver insert inside the engine and has to go back in this exact position.
Remove the pump. I left the hose connected as the jubilee clip is not re-useable if removed. Where the hose connects to the brake servo inlet its a simple push click button to remove so I disconnected at that end instead.
With the pump out you can see where the oil was leaking, both from the O ring and also the pump seal itself.
Dismantle the pump by removing the five torx bolts at the rear. You can now remove the back. Its difficult to see from the photo but the seal is completely recessed which explains the leak. These seals are well known for compressing like this and the lack of pressure against the back plate results in leaks.
Clean the vacuum pump up with some degunk spray to remove all oil from the seal recess.
After speaking with a friend who is an ex Sytner mechanic he explained the only way you can fix these permenantly is by installing a more subtantial and appropriate seal and he found out quite by chance the perfect replacement is the seal which is supplied with a standard E90 engine oil filter! Its a fraction thicker than the origional and provides an absolutely perfect tight seal.
I then placed a small smear of gasket sealer in the seal recess. This is actualy more to hold the new seal in place whilst re-assembling as the seal has to be stretched a little to fit in and tends to spring out if theres no sealer to help keep it held down.
Once the new seal was installed....
...I placed a small amount of gasket sealer around the outer circumference of the seal.
This is not an essential step as the new seal is more tha sufficient but I just wanted to go the belt and braces route! I used the recomended heat resistant up to 230oc gasket sealer.
All done, clamp it back together with the torx bolts nice and tight, wipe any excess gasket sealer away, install the new O ring (Part no. 11667509080) and re-install.
Installation is every bit as awkward as removal, with the added complexity of lining the cam connector up. You can feel the position of the connector insert if you run your finger over it inside the rear of the cylinder head, theres no easy way unfortunately just keep rotating the pump connector a tiny amount each time until it finaly slides in.
Then replace the three bolts, again difficult to locate them and tighten due to lack of space to get your hands in.
Re-assemble the engine cover, strut braces etc in reverse order of removal.
DO NOT START THE ENGINE. Most gasket sealer will take a while to set, give it three or four hours to harden before starting up the car.
Whilst waiting for it to harden, take the opertunity to jack the car up, remove the engine under tray and spray some degunk up the heat sheild above the exhaust cat. The Vacuum pump is just visible from underneat and you can see the trail of oil down the bulkhead heat shield which then drops onto the cat causing the burning smell.
Degunk, wash and wipe down or you will have oil remnants continue to drip as a result of the old leak for weeks until its all gone.
Thats it, gave the engine bay a 2 hour clean whilst waiting, then fired her up and no leaks.
Driven about 800 miles in the last three days so thought I would remove the undertray and have a look this afternoon.... spotless!
I will report back any problems but hopefuly with the enhanced seal it will stay dry.
The whole job took about 4.5hours, I did not need to remove the rocker cover, it may have made life easier as I could have seen the slot position for the pump when re-installing, but for the risk of disturbing a perfectly good valve cover gasket and the cost of a new one (£80 from BMW) its was well worth avoiding.
Hope this helps folks
:thumbs:
Our E90's Vacuum pump seal is leaking and i'll be giving it a DIY this weekend.
Found this useful thread that can hopefully help someone else with the same issue, instead of bmw charging the earth for a new pump.
E90 N46 Vacuum Pump removal, repair and reinstatement guide
As there does not seem to be a guide for this anywhere I did the repair today and thought I would post my experience to try and help anyone else attempting this in the future.
There are lots of suggestions that using gasket sealer is a short term fix, this guide uses the installation of two new seals to provide a permenant repair and hopefuly save you the agro of repeating the process ever again, trust me once is enough You will also not need to remove the rocker cover gasket to complete this repair despite what I was told by BMW and two indys I consulted.
The best quote I got for this repair was from an indy in Sheffield, £360 for a new Vacuum Pump, £80 for a Valve Cover Gasket, £200 6 hours of labor - Total Indy £640. Total cost for DIY £8.49
Symptoms:
Intermittent smell of burning oil blown through the air vents into the cabin
Brief plumes of white smoke from under the bonnet
Tickover RPM's fluctuation (Searching between 500-700rpm)
Loosing oil
Fault:
Brake Vacuum pump main seal leaking
Brake Vacumm pump O ring leaking
Required:
E90 Engine oil filter with seals
O ring (Part number 11667509080)
Procedure:
1> Remove the two plastic covers at the far side of the cabin micro filter housing
2> Unclip and remove the cable carrier
3> Remove the 7 x 8mm bolts holding the cabin microfilter housing in place and then remove the housing
4> Once the above is removed you can remove the two strut barces. Torx bolts hold the far ends on place. The centre bolt is found under a plastic circular cover (5). Pop it out with a screw driver and remove the bolt. The strut braces then slide straight out.
6> Remove the cabin micro filter under tray.
You now have fairly good access to the engine but the Vacuum Pump is still not visible. To access the Vacuum Pump remove the plastic cover from the top of the engine. Just lift up and pull, it comes away easily.
With the platic engine cover off you can now see the vacuum pump.
Its right up against the bulkhead of the car and the three 10mm retaining bolts can only be located by sliding your hand behind and feeling for them. Be under no doubt, there is about 40mm of space between the pump and the bulk head, its fiddly, frustrating and awkward.
Use a quarter drive with a 10mm socket to remove the three bolts.
The vacuum pump will then slide straight out. Just as it pulls out, take a photograph of the locator position, this is the part of the pump which connects to the cam driver insert inside the engine and has to go back in this exact position.
Remove the pump. I left the hose connected as the jubilee clip is not re-useable if removed. Where the hose connects to the brake servo inlet its a simple push click button to remove so I disconnected at that end instead.
With the pump out you can see where the oil was leaking, both from the O ring and also the pump seal itself.
Dismantle the pump by removing the five torx bolts at the rear. You can now remove the back. Its difficult to see from the photo but the seal is completely recessed which explains the leak. These seals are well known for compressing like this and the lack of pressure against the back plate results in leaks.
Clean the vacuum pump up with some degunk spray to remove all oil from the seal recess.
After speaking with a friend who is an ex Sytner mechanic he explained the only way you can fix these permenantly is by installing a more subtantial and appropriate seal and he found out quite by chance the perfect replacement is the seal which is supplied with a standard E90 engine oil filter! Its a fraction thicker than the origional and provides an absolutely perfect tight seal.
I then placed a small smear of gasket sealer in the seal recess. This is actualy more to hold the new seal in place whilst re-assembling as the seal has to be stretched a little to fit in and tends to spring out if theres no sealer to help keep it held down.
Once the new seal was installed....
...I placed a small amount of gasket sealer around the outer circumference of the seal.
This is not an essential step as the new seal is more tha sufficient but I just wanted to go the belt and braces route! I used the recomended heat resistant up to 230oc gasket sealer.
All done, clamp it back together with the torx bolts nice and tight, wipe any excess gasket sealer away, install the new O ring (Part no. 11667509080) and re-install.
Installation is every bit as awkward as removal, with the added complexity of lining the cam connector up. You can feel the position of the connector insert if you run your finger over it inside the rear of the cylinder head, theres no easy way unfortunately just keep rotating the pump connector a tiny amount each time until it finaly slides in.
Then replace the three bolts, again difficult to locate them and tighten due to lack of space to get your hands in.
Re-assemble the engine cover, strut braces etc in reverse order of removal.
DO NOT START THE ENGINE. Most gasket sealer will take a while to set, give it three or four hours to harden before starting up the car.
Whilst waiting for it to harden, take the opertunity to jack the car up, remove the engine under tray and spray some degunk up the heat sheild above the exhaust cat. The Vacuum pump is just visible from underneat and you can see the trail of oil down the bulkhead heat shield which then drops onto the cat causing the burning smell.
Degunk, wash and wipe down or you will have oil remnants continue to drip as a result of the old leak for weeks until its all gone.
Thats it, gave the engine bay a 2 hour clean whilst waiting, then fired her up and no leaks.
Driven about 800 miles in the last three days so thought I would remove the undertray and have a look this afternoon.... spotless!
I will report back any problems but hopefuly with the enhanced seal it will stay dry.
The whole job took about 4.5hours, I did not need to remove the rocker cover, it may have made life easier as I could have seen the slot position for the pump when re-installing, but for the risk of disturbing a perfectly good valve cover gasket and the cost of a new one (£80 from BMW) its was well worth avoiding.
Hope this helps folks
:thumbs:
