335i/ N55 bottom end failure after oil filter housing gasket
Discussion
Hi.
My 335i has 78k miles on it, I'm the 2nd owner and have had it for just under 10 years/ since 34k miles. It's just had the oil filter housing/ oil cooler gaskets changed. On the way home from the garage, approx 9 miles, the engine stopped unexpectedly between slow speed gear change (it's a manual). It did restart and so I carried on driving. 135 miles later it has what must be a bottom end knock under light throttle 2-3000 rpm, you notice driving slowly esp on gear changes. So I've not driven it, am getting an oil analysis done using oil from the oil filter housing, but it it's pretty clear from the oil that drained from the oil filter that there is glittery metal in the oil. And if you shine a light on the oil filter you can see bits of metal here and there that have been caught. I suspect that the unexpected engine stop was a big end bearing seizing briefly. I've read similar accounts from other people, one almost exactly the same sequence of events after OFHG replacement, engine stop, then rod knock.
So wondering what to do, the garage that did the work don't think the failure of the bottom is connected to the change of the OFHG. I've read that BMW released a tech bulletin about priming the oil system - there's a blog from FCP Euro on link [1] and the actual BMW document [2]. The garage that did the work and 1 other I've spoken to dismissed that bulletin, saying it either only applies to the american market or is only to ensure the vanos and hydraulics in the engine have oil before it fires up. The blog post and other stuff I've read suggest differently. The garage that did my OFHG weren't aware of the priming process so didn't do it, and don't believe that not-doing it contributed to the engine failure.
One place I spoke to said they wouldn't rebuild an engine that had failed, thought there is too much risk of metal having made its way to other parts of the engine like the vanos etc.
Any advice on this appreciated - esp re rebuilding the existing engine, whether anyone has successfully done a bottom end rebuild after a simlar problem?
Anyone know who might do a rebuild in south of England? I heard good reports about Mr Vanos but Darlington is a long way from me so not easy to get the car there.
[1] https://blog.fcpeuro.com/bmw-si-b11-09-15-preventi...
[2] https://static.nhtsa.gov/odi/tsbs/2016/MC-10151166...
My 335i has 78k miles on it, I'm the 2nd owner and have had it for just under 10 years/ since 34k miles. It's just had the oil filter housing/ oil cooler gaskets changed. On the way home from the garage, approx 9 miles, the engine stopped unexpectedly between slow speed gear change (it's a manual). It did restart and so I carried on driving. 135 miles later it has what must be a bottom end knock under light throttle 2-3000 rpm, you notice driving slowly esp on gear changes. So I've not driven it, am getting an oil analysis done using oil from the oil filter housing, but it it's pretty clear from the oil that drained from the oil filter that there is glittery metal in the oil. And if you shine a light on the oil filter you can see bits of metal here and there that have been caught. I suspect that the unexpected engine stop was a big end bearing seizing briefly. I've read similar accounts from other people, one almost exactly the same sequence of events after OFHG replacement, engine stop, then rod knock.
So wondering what to do, the garage that did the work don't think the failure of the bottom is connected to the change of the OFHG. I've read that BMW released a tech bulletin about priming the oil system - there's a blog from FCP Euro on link [1] and the actual BMW document [2]. The garage that did the work and 1 other I've spoken to dismissed that bulletin, saying it either only applies to the american market or is only to ensure the vanos and hydraulics in the engine have oil before it fires up. The blog post and other stuff I've read suggest differently. The garage that did my OFHG weren't aware of the priming process so didn't do it, and don't believe that not-doing it contributed to the engine failure.
One place I spoke to said they wouldn't rebuild an engine that had failed, thought there is too much risk of metal having made its way to other parts of the engine like the vanos etc.
Any advice on this appreciated - esp re rebuilding the existing engine, whether anyone has successfully done a bottom end rebuild after a simlar problem?
Anyone know who might do a rebuild in south of England? I heard good reports about Mr Vanos but Darlington is a long way from me so not easy to get the car there.
[1] https://blog.fcpeuro.com/bmw-si-b11-09-15-preventi...
[2] https://static.nhtsa.gov/odi/tsbs/2016/MC-10151166...
You have my sympathy. I have the same engine and gearbox in a 5 Series which is now sporting a brand new crate engine plus low mileage gearbox.
I bought my 535i in July 2022 and it was on around 88k miles. Not long after buying it me and a friend replaced the OFHG gaskets and we did not do the oil priming procedure. I mentioned it but he said it doesn't need it. I had bought some Viton gaskets thinking they'd last longer but they didn't seal properly. Therefore, we did the OFHG gaskets for a second time in May 2023 on 95k miles. Once again, without any oil priming procedure other than pouring some oil down the housing.
Unfortunately, I cannot recall exactly when my various different noises started in relation to this second OFHG replacement. I thought I had a gearbox issue that was caused by running too much torque through it. I was running Stage 2+ MHD which is up to 460lb/ft for a gearbox rated to 333lb/ft. I had sort of accepted I'd need a new one at some point and carried on driving. As it turned out following the engine replacement I did still have a noise like a bag of spanners coming from the rear end of the gearbox and have since swapped it for one I found in the Netherlands with only 1,250km on it.
The issue I thought was isolated to the gearbox got worse. By the end, if I accelerated hard in a high gear (thus putting it under a high torque load) there was a thumping that resonated throughout the car. When stationary with the clutch dipped if you revved it gently there was a nasty grumbling that resonated and shook the car just under 2krpm. At this point I realised I also had a problem with the engine. Upon inspecting the oil filter it had ferrous glitter sprinkled right through it and it was clear this wasn't just normal bearing material.
I stopped driving the car and began speaking to various engine specialists. Mr Vanos and Williams Performance failed to return my emails and voicemails. It came down to a local engine builder and CPC Engineering in Amersham who came recommended via a forum. There was a place in the Midlands who said they could change out the bearings (and probably a new crankshaft) via the bottom whilst the engine was still in the car. However, most places warned against this due to the glitter travelling and causing further damage to areas like the oil pump etc.
A rebuild on the lucky side might just have been cheaper but on the unlucky side was coming out more expensive than a new engine. Think 50-60hrs labour at £100p/h plus parts... Second hand engines are kind of pointless unless you're going to rebuild them before installing it into your car as you've no idea how worn they are. Sadly, they are all priced too highly to make this a viable option.
I decided to go with Phil's recommendation from CPC, which is a new crate engine from BMW. Bought privately this is horrendously expensive at nearly £16k. However, CPC are registered as a specialist with BMW and so BMW will sell them engines at a massively discounted price to help keep older cars on the road. The engine was £7,320 and included everything from sump to valve cover but no ancillaries. It did have spark plugs but no injectors or coils, I bought new ones anyway. There was a new water pump attached but I'd only replaced mine hundreds of miles ago with an all metal one so I kept mine. They have to send your old engine back with the same parts as what gets given to you. The labour was 19.5hrs at £108.90p/h plus £84 aircon regas. I also took the opportunity to exchange the turbo for a remanufactured one, which was another £959. They used engine oil I had but charged for coolant and a coolant line that needed replacing. All in circa £10,500.
I did not pay to have my old engine stripped down so I'll never know the extent of the damage inside but I highly suspect some spun conrod and/or main bearings. Below is a video of the sound it made on idle and it still ran. I suspect when yours stopped that was one or more bearings spinning. They still run with a spun bearing but whilst causing further nasty damage.
There are people who have spun bearings at lower mileage and those who have done much more than 100k (the point I stopped driving mine). It is certainly possible that not priming the oil after OFHG gasket replacement contributed to the failure, although the bearings were probably already very worn too. Phil didn't seem to think not priming the oil would cause it but there's too many stories like this for it to be a coincidence.
Good luck with whatever you do. I'd be giving Phil at CPC Engineering a call if you want to keep the car.
https://youtu.be/iVLu8GXPgwo?si=PThtmAx0avjIveHq
I bought my 535i in July 2022 and it was on around 88k miles. Not long after buying it me and a friend replaced the OFHG gaskets and we did not do the oil priming procedure. I mentioned it but he said it doesn't need it. I had bought some Viton gaskets thinking they'd last longer but they didn't seal properly. Therefore, we did the OFHG gaskets for a second time in May 2023 on 95k miles. Once again, without any oil priming procedure other than pouring some oil down the housing.
Unfortunately, I cannot recall exactly when my various different noises started in relation to this second OFHG replacement. I thought I had a gearbox issue that was caused by running too much torque through it. I was running Stage 2+ MHD which is up to 460lb/ft for a gearbox rated to 333lb/ft. I had sort of accepted I'd need a new one at some point and carried on driving. As it turned out following the engine replacement I did still have a noise like a bag of spanners coming from the rear end of the gearbox and have since swapped it for one I found in the Netherlands with only 1,250km on it.
The issue I thought was isolated to the gearbox got worse. By the end, if I accelerated hard in a high gear (thus putting it under a high torque load) there was a thumping that resonated throughout the car. When stationary with the clutch dipped if you revved it gently there was a nasty grumbling that resonated and shook the car just under 2krpm. At this point I realised I also had a problem with the engine. Upon inspecting the oil filter it had ferrous glitter sprinkled right through it and it was clear this wasn't just normal bearing material.
I stopped driving the car and began speaking to various engine specialists. Mr Vanos and Williams Performance failed to return my emails and voicemails. It came down to a local engine builder and CPC Engineering in Amersham who came recommended via a forum. There was a place in the Midlands who said they could change out the bearings (and probably a new crankshaft) via the bottom whilst the engine was still in the car. However, most places warned against this due to the glitter travelling and causing further damage to areas like the oil pump etc.
A rebuild on the lucky side might just have been cheaper but on the unlucky side was coming out more expensive than a new engine. Think 50-60hrs labour at £100p/h plus parts... Second hand engines are kind of pointless unless you're going to rebuild them before installing it into your car as you've no idea how worn they are. Sadly, they are all priced too highly to make this a viable option.
I decided to go with Phil's recommendation from CPC, which is a new crate engine from BMW. Bought privately this is horrendously expensive at nearly £16k. However, CPC are registered as a specialist with BMW and so BMW will sell them engines at a massively discounted price to help keep older cars on the road. The engine was £7,320 and included everything from sump to valve cover but no ancillaries. It did have spark plugs but no injectors or coils, I bought new ones anyway. There was a new water pump attached but I'd only replaced mine hundreds of miles ago with an all metal one so I kept mine. They have to send your old engine back with the same parts as what gets given to you. The labour was 19.5hrs at £108.90p/h plus £84 aircon regas. I also took the opportunity to exchange the turbo for a remanufactured one, which was another £959. They used engine oil I had but charged for coolant and a coolant line that needed replacing. All in circa £10,500.
I did not pay to have my old engine stripped down so I'll never know the extent of the damage inside but I highly suspect some spun conrod and/or main bearings. Below is a video of the sound it made on idle and it still ran. I suspect when yours stopped that was one or more bearings spinning. They still run with a spun bearing but whilst causing further nasty damage.
There are people who have spun bearings at lower mileage and those who have done much more than 100k (the point I stopped driving mine). It is certainly possible that not priming the oil after OFHG gasket replacement contributed to the failure, although the bearings were probably already very worn too. Phil didn't seem to think not priming the oil would cause it but there's too many stories like this for it to be a coincidence.
Good luck with whatever you do. I'd be giving Phil at CPC Engineering a call if you want to keep the car.
https://youtu.be/iVLu8GXPgwo?si=PThtmAx0avjIveHq
Thanks for taking the time to write that, really appreciate it. Completely agree re used engines, pointless unless they're cheap enough and you know what you're getting.
Interesting you had done your water pump, mine was also replaced with a Pierburg all-metal water pump in the visit as the the oil filter housing gasket. It replaced an OEM water pump which was fitted only 20,000 miles ago by BMW (at my expense sadly). I sourced it as the garage would have happily fitted OEM or similar with plastic impeller cover and I wanted the best chance of avoiding that expense for a 3rd time in the near future.
Your engine sounded quite bad on your video, mine still sounded normal at tickover when I turned it off, but just don't know how bad it is internally, I guess would have to assume at least some rods and oil pump would need replacing and machined/ new crankshaft at an absolute minimum. Mine is completely standard, had full BMW service history until now, always looked after when starting from cold, oil changes every few thousand miles, so it's really annoying for this to happen.
I'll give CPC a call, thanks again.
Interesting you had done your water pump, mine was also replaced with a Pierburg all-metal water pump in the visit as the the oil filter housing gasket. It replaced an OEM water pump which was fitted only 20,000 miles ago by BMW (at my expense sadly). I sourced it as the garage would have happily fitted OEM or similar with plastic impeller cover and I wanted the best chance of avoiding that expense for a 3rd time in the near future.
Your engine sounded quite bad on your video, mine still sounded normal at tickover when I turned it off, but just don't know how bad it is internally, I guess would have to assume at least some rods and oil pump would need replacing and machined/ new crankshaft at an absolute minimum. Mine is completely standard, had full BMW service history until now, always looked after when starting from cold, oil changes every few thousand miles, so it's really annoying for this to happen.
I'll give CPC a call, thanks again.
Edited by thecube on Monday 8th January 18:05
You're welcome, it's what forums are for.
Mine was indeed the Pierburg unit you mention. I don't know if it was still original or replaced at least once, didn't have any receipts for it and was close to 100k.
Mine had a good service history too. I potentially did thousands of miles after damage had started to occur. You might fair better as you've caught it much earlier.
Keep us posted.
Mine was indeed the Pierburg unit you mention. I don't know if it was still original or replaced at least once, didn't have any receipts for it and was close to 100k.
Mine had a good service history too. I potentially did thousands of miles after damage had started to occur. You might fair better as you've caught it much earlier.
Keep us posted.
Quick update. I talked to CPC and they were very helpful and knowledgable. I asked them about inspecting the rod bearings and crank journals while the engine is in the car and had booked it in, but the more I read and thought about it, I decided that it's unlikely the crank would have survived unscathed if it has spun a bearing, and I wouldn't know what the main crank bearings were like unless the engine comes out. It quickly gets expensive and I came to the same conclusion, it's either a new engine or sell the car as is. I'm waiting for a quote for a new engine at the moment and cancelled the inspection.
I did some more searching about the BMW priming process that specifies cranking on the starter with fuel/ ignition disabled, and how it differs to just starting the engine and idling. I haven't found anything definitive yet, but I did find this thread (there are others with similar comments out there) - one person commented:
"The theory is that the variable oil pump is to blame. At idle (and other conditions), the ECU reduces the displacement of the oil pump to reduce parasitic drag. This minimum output mode is not enough to push air locks in the lines out of the way -> spun bearing. During cranking the ECU leaves the oil pump at default, which is full flow, so oddly there is more oil flow during cranking than at idle."
Link here:
https://bobistheoilguy.com/forums/threads/prime-bm...
As they say on the news, more on this story later . . .
I did some more searching about the BMW priming process that specifies cranking on the starter with fuel/ ignition disabled, and how it differs to just starting the engine and idling. I haven't found anything definitive yet, but I did find this thread (there are others with similar comments out there) - one person commented:
"The theory is that the variable oil pump is to blame. At idle (and other conditions), the ECU reduces the displacement of the oil pump to reduce parasitic drag. This minimum output mode is not enough to push air locks in the lines out of the way -> spun bearing. During cranking the ECU leaves the oil pump at default, which is full flow, so oddly there is more oil flow during cranking than at idle."
Link here:
https://bobistheoilguy.com/forums/threads/prime-bm...
As they say on the news, more on this story later . . .
Yes, says crank for 10 seconds, rest starter for 20 seconds to allow it to cool, repeat a further 2 times. That's what the BMW document says.
I've also heard monitor the oil pressure via OBD during cranking but that's not what the BMW doc says, I don't know how realtime the OBD data would be.
Hoping to find something more definitive on reason for rod bearing failure when priming isn't followed, because I just don't believe my engine failure is a coincidence. There are so many stories on this out there and the way things followed on mine was so similar.
I've also heard monitor the oil pressure via OBD during cranking but that's not what the BMW doc says, I don't know how realtime the OBD data would be.
Hoping to find something more definitive on reason for rod bearing failure when priming isn't followed, because I just don't believe my engine failure is a coincidence. There are so many stories on this out there and the way things followed on mine was so similar.
Just coming back to this for the benefit of others.
Thanks SteveN for the tips, I ended up doing pretty much the same as you, brand new crated engine from BMW, recon turbo, all fitted by CPC in Amersham who were great. Expensive process, what a waste of money for something so easily avoided with the right information.
I read a lot of forum posts, spoke to a few garages, and even chatted with someone in the USA who I came across via a Facebook group who had a bunch of tips, not just about priming the oil system . Quite a lot of people out there saying "yeah I've done loads of oil filter housing gaskets, never happened to me" and also plenty of stories from people like me who it did happen to. Others saying "pour oil in through the oil filter housing when refilling afterwards" which I think is mostly a waste of time as most of the oil will drain back through the centre hole as it does when you unscrew and remove the oil filter cap. I think those people who do that have been lucky.
Also heard "yeah that's a problem in the American market". Seems very hard to believe, I haven't gone to the trouble of checking part numbers to see if there are different part numbers or anything, but the American market buys a lot more petrol cars and therefore there will be more N55s and therefore more cases of it happening over there due to volume of N55-powered cards sold over there. I did see one post about the later N55 engine having a revised oil pump.
I know there's speculation about why oil starvation happens after breaking the oil circuit (breaking it to do things like the oil filter housing gasket). The problem sounds liks a combination of the air in the oil lines, the variable deliver of the oil pump on the N55 (low delivery at idle), and some have suggested maybe with the sump empty while the oil circuit open, the pump also empties, affecting how it sucks up oil on restart or doesn't (again speculation). I think it must a combination and unhappy coincidence of all of those for the unlucky ones of us that end up with bottom end failure. In link [4] below, the helpful bloke who posted it - a BMW specialist in USA - has seen it take over a minute of cranking before there was oil in the oil filter housing, because he went to the trouble of unscrewing the oil filter to check. I swapped messages with him on Facebook. As he says, can you imagine if the engine starts immediately, no oil to the crank bearings for a whole minute. He also has a bunch of other tips in that post including letting the car go to sleep before disconnecting the battery to avoid corrupting FRM modules (common problem).
I've included the first BMW service bulletin in link [1] below and a later one [2] that explicitly refers to the affected engines including the N55.
Link [3] is to a video about how to do the priming process. Even though they posted that to illustrate how BMW recommend it, they replied to a comment I made saying they have a tool to prime the oil circuit. Some other posts I read suggest this is being done by pumping oil in using the oil pressure sensor hole on the oil filter housing. They might be worth asking where they got that tool or if they made it.
The other recommendations I've seen are:
- before starting the job to change the oil filter housing gasket, pull the fuel pump fuse and run the engine until it stops. Leave the fuse out. That way you don't have to unplug the injector harness to do the priming.
- remove the spark plugs to do the priming to give the starter motor an easier time and faster cranking
Hope this helps some others out there.
Thanks again SteveN.
[1] https://static.nhtsa.gov/odi/tsbs/2016/MC-10151166...
[2] https://static.nhtsa.gov/odi/tsbs/2022/MC-10225106...
[3] https://www.youtube.com/watch?v=85cqTnY_8bY
[4] https://www.facebook.com/groups/597554073682202/po...
Thanks SteveN for the tips, I ended up doing pretty much the same as you, brand new crated engine from BMW, recon turbo, all fitted by CPC in Amersham who were great. Expensive process, what a waste of money for something so easily avoided with the right information.
I read a lot of forum posts, spoke to a few garages, and even chatted with someone in the USA who I came across via a Facebook group who had a bunch of tips, not just about priming the oil system . Quite a lot of people out there saying "yeah I've done loads of oil filter housing gaskets, never happened to me" and also plenty of stories from people like me who it did happen to. Others saying "pour oil in through the oil filter housing when refilling afterwards" which I think is mostly a waste of time as most of the oil will drain back through the centre hole as it does when you unscrew and remove the oil filter cap. I think those people who do that have been lucky.
Also heard "yeah that's a problem in the American market". Seems very hard to believe, I haven't gone to the trouble of checking part numbers to see if there are different part numbers or anything, but the American market buys a lot more petrol cars and therefore there will be more N55s and therefore more cases of it happening over there due to volume of N55-powered cards sold over there. I did see one post about the later N55 engine having a revised oil pump.
I know there's speculation about why oil starvation happens after breaking the oil circuit (breaking it to do things like the oil filter housing gasket). The problem sounds liks a combination of the air in the oil lines, the variable deliver of the oil pump on the N55 (low delivery at idle), and some have suggested maybe with the sump empty while the oil circuit open, the pump also empties, affecting how it sucks up oil on restart or doesn't (again speculation). I think it must a combination and unhappy coincidence of all of those for the unlucky ones of us that end up with bottom end failure. In link [4] below, the helpful bloke who posted it - a BMW specialist in USA - has seen it take over a minute of cranking before there was oil in the oil filter housing, because he went to the trouble of unscrewing the oil filter to check. I swapped messages with him on Facebook. As he says, can you imagine if the engine starts immediately, no oil to the crank bearings for a whole minute. He also has a bunch of other tips in that post including letting the car go to sleep before disconnecting the battery to avoid corrupting FRM modules (common problem).
I've included the first BMW service bulletin in link [1] below and a later one [2] that explicitly refers to the affected engines including the N55.
Link [3] is to a video about how to do the priming process. Even though they posted that to illustrate how BMW recommend it, they replied to a comment I made saying they have a tool to prime the oil circuit. Some other posts I read suggest this is being done by pumping oil in using the oil pressure sensor hole on the oil filter housing. They might be worth asking where they got that tool or if they made it.
The other recommendations I've seen are:
- before starting the job to change the oil filter housing gasket, pull the fuel pump fuse and run the engine until it stops. Leave the fuse out. That way you don't have to unplug the injector harness to do the priming.
- remove the spark plugs to do the priming to give the starter motor an easier time and faster cranking
Hope this helps some others out there.
Thanks again SteveN.
[1] https://static.nhtsa.gov/odi/tsbs/2016/MC-10151166...
[2] https://static.nhtsa.gov/odi/tsbs/2022/MC-10225106...
[3] https://www.youtube.com/watch?v=85cqTnY_8bY
[4] https://www.facebook.com/groups/597554073682202/po...
I guess you'll be keeping the car a long time then like me. Averaging out the cost over ten years makes it more sensible, especially compared to laying out cash on a newer car, which would be more expensive.
I'm still continuing the process of renewing parts on mine. Since the engine I've fitted a new crankshaft damper pulley and alternator. Got a low pressure fuel pump with regulator to fit tomorrow, might do the high pressure pump later this year so that all the known weak points are done.
Thanks for the links and extra info, I'm certainly going to be extra careful when it comes to things like the OFHG again...!
I'm still continuing the process of renewing parts on mine. Since the engine I've fitted a new crankshaft damper pulley and alternator. Got a low pressure fuel pump with regulator to fit tomorrow, might do the high pressure pump later this year so that all the known weak points are done.
Thanks for the links and extra info, I'm certainly going to be extra careful when it comes to things like the OFHG again...!
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