Ugan 41 Report post Posted July 23, 2015 Hi Any ideas what this may be only when the car is at full operating temperature from standstill when I take off or at idle there is a puff of white smoke. It does not always happen, just time to time also noticed when stationary there is an unusual vibration as in was not there last week when I used the car. It's not my daily right now anyway but would still like to sort it out before it gets worse. Cheers Quote Share this post Link to post Share on other sites
B.M.W Ltd 950 Report post Posted July 23, 2015 N42 valvetronic motor? those symptoms = valve stem seals Quote Share this post Link to post Share on other sites
Ugan 41 Report post Posted July 23, 2015 N42 valvetronic motor? those symptoms = valve stem seals Yes it is n42. Thanks Glen. Quote Share this post Link to post Share on other sites
Ahmedsinc 414 Report post Posted July 23, 2015 Oh dear, another one bites the dust! Quote Share this post Link to post Share on other sites
Ugan 41 Report post Posted July 23, 2015 Could explain why it was sold so cheap but exact spec I wanted now to get it sorted for the new year as my daily. Quote Share this post Link to post Share on other sites
zero 1160 Report post Posted July 24, 2015 As Glenn says, it is almost 100% guaranteed to be valve stem seals. The N42 and N46 motors were plagued by this problem - usually because of lack of maintenance or incorrect oil. There is other maintenance that can be done to slow the speed of the problem getting worse - using correct oil and changing it at correct intervals, cleaning out or replacing ccv valve, cleaning out or replacing ccv valve hoses, cleaning out or replacing vaccuum pump, cleaning out gunk from the engine(engine flushes etc). The problem will continue to get worse though. If you do get the valve stem seals done (I'm rebuilding one of these motors at the moment) then make sure you take care of the other maintenance too to limit the chances of it happening again. How many kms on your motor? This thread with my experiences might help; http://bimmersport.co.nz/topic/48568-ccv-valve-help/ Quote Share this post Link to post Share on other sites
Ugan 41 Report post Posted July 24, 2015 Hey, thanks for the advice. It's nz new done 155k , it's definitely valve stem seals, just will maintain as it until it stops working. will see what finances are by the new year. Where do you buy yours spares from going to bye a whole lot of parts suspension to engine? Cheers 1 Quote Share this post Link to post Share on other sites
zero 1160 Report post Posted July 24, 2015 Hey, thanks for the advice. It's nz new done 155k , it's definitely valve stem seals, just will maintain as it until it stops working. will see what finances are by the new year. Where do you buy yours spares from going to bye a whole lot of parts suspension to engine? Cheers I'm replacing them myself but its not cheap. It cost me about $600 for valve stem seals, head gasket, and upper engine gasket set. I bought from these guys - http://www.euromarketing.co.nz/ Cams will have to be aligned afterwards which has to be done by a specialist as it needs an expensive bmw tool to do it - I'm not sure on the cost of that yet. This thread has my engine build info on it, but it needs updating as I've made further progress; http://bimmersport.co.nz/topic/52977-n42n46-engine-rebuild/ Unless you are very attached to your car, you need to consider if it is worth keeping, as the valve seals will only get worse until they are replaced, and I would guess a mechanic would charge in the region of $1500 - $2000. The other option is to swap in a used 6 cylinder motor as they are excellent, but I wanted to keep the 4 cylinder in mine. I see you are reasonably close to me - I'm happy to have a look at your engine and give you a few pointers if that helps. Quote Share this post Link to post Share on other sites
B.M.W Ltd 950 Report post Posted July 24, 2015 (edited) All valvetronic motors can give valve stem seal problems.. 6's & 8's too. On a ratio though, the 4's are more problematic Edited July 24, 2015 by B.M.W Ltd 1 Quote Share this post Link to post Share on other sites
Ugan 41 Report post Posted July 24, 2015 Cheers Glen will look at getting them repaired for now. Quote Share this post Link to post Share on other sites
allan 295 Report post Posted July 24, 2015 The advise given both by Glenn and Nathan is sound you are up for $$$$$ no matter what you do. Do some research and the numbers on fixing the current raft of problems with your N42 and then doing a six cylinder conversion you might be surprised. 1 Quote Share this post Link to post Share on other sites
Ugan 41 Report post Posted July 25, 2015 Thanks for the advice all, will weight out my options and make a choice. Quote Share this post Link to post Share on other sites
zero 1160 Report post Posted July 25, 2015 All valvetronic motors can give valve stem seal problems.. 6's & 8's too. On a ratio though, the 4's are more problematic Glenn, would you say these problems come from poor maintenance and incorrect/old oil, or is it a design fault from BMW? Quote Share this post Link to post Share on other sites
B.M.W Ltd 950 Report post Posted July 25, 2015 (edited) Glenn, would you say these problems come from poor maintenance and incorrect/old oil, or is it a design fault from BMW? Seal size & material are probably more the cause. A 6mm valve stem doesn't give a lot of area for sealing , however, other manufacturers seem to get it right Edited July 25, 2015 by B.M.W Ltd 1 Quote Share this post Link to post Share on other sites
zero 1160 Report post Posted July 25, 2015 Seal size & material are probably more the cause. A 7mm valve stem doesn't give a lot of area for sealing , however, other manufacturers seem to get it right Surprising you cant get viton seals for them. I searched high and low for aftermarket seals before I ended up buying the stock bmw ones. Quote Share this post Link to post Share on other sites
