BMW E46 / N42: Timing Chain Tensioner, how to compare and test (old and updated designs)

[@pavelhorak1888]

Hello, I bought the tensioner on my N43, as compare with old original was the same (newer improved version both), but the old one I pump the oil in (in the can with oil) and oil flows out from hole on the very very slowly and hardly to press...the new one I tested it too, but oil flows out from the tip quite easily. What version is good? With the new one the car starts up for a long time!!! (4 seconds...) With the old one, during the start engine control light lights up with ECU issue of Cranshaft position sensor (replaced too) and rattling for a while after start (2 seconds...). Otherwise there is no rattling sound, chain is tight when engine runs.

[@RepairDIY]

Hi, make sure the both have free travel when no oil in the tensioners. I amy be wrong but i do think if the piston doesn't stuck when no oil in it, then after filled with oil, the harder the better. To me, 4 seconds for a cold engine start is not a big issue, neither 2 second rattle after start (I had 10 minute rattle!), but warning light or sensor fault code are the concerns. it turned out that my biggest problem was low oil pressure. I have made several videos on the oil pressure related issues. Now my car runs smoothly and quietly. Good luck to you!

[@pavelhorak1888]

@@RepairDIY Thanks for report. I must to solve it because during the start the camshaft position sensor fault lights up often... Also, 30minutes later I spoke with authorized BMW mechanic, sice 2016 there is a new OEM tensioner for these engines. New version (ver.3) have got improved oil hole, radius and !!!! stronger spring !!! Is possible to preserve chain thighten during long engine standing. And starting engine is without a noise. OEM number is 11318685091

[@RepairDIY]

@@pavelhorak1888 Hi, if your oil pump ok, oil pickup strainer not blocked, good quality oil, you should have the oil pressure build up within 2 seconds. you can observe the oil pressure light while starting the engine. after the engine standing for a long time, the oil in the system may go abck to the oil sump, but I don't suppose the oil in the chain tensioner will go out much. In my car the oil pressure caused more problem than the timing chain tensioner. good luck!

[@bmwisbest1405]

Same problem for N46 318i e90 no?

[@RepairDIY]

Hi, I am not sure. As the N46 is the newer engine to replace the N42, it could be similar. You could look at your engine to see if you could find the similar chain tensioner. Good luck.

[@bmwisbest1405]

@@RepairDIY thanks

[@RepairDIY]

@@olindor220 great to know. thank you!

[@aaronbligh3619]

Bubble, bubble press down there be more bubble. brilliant thanks 🙂