Some manufactures have an o ring sizing chart.
													
																	Disa valve o ring size. 
									
																	As a bmw owner and a diyer i did this job myself. 
																	The orange circle is the o ring that will be replaced. 
																	In the old disa designs the ring came separately under part number 11617504543. 
																	Replacing the o ring is a fraction of that. 
															
													
									
																	It was a long research to find the correct o ring because there is no part number for this o ring for bmw s made after 2001. 
																	View product 6 lostar intake manifold disa valve repair kit for bmw e39 e46 e83 325i 525i m54 2 2 2 5l. 
																	Ours are black with a clear coating the valve will be dirty. 
																	Free shipping for many products. 
															
													
									
																	Free in store or curbside pick up. 
																	Clean it with a simple spray cleaner and rag. 
																	X 2 5mm thickness o ring. 
																	View product 5 bmw 3 0l m54 disa valve repair upgrade kit for 3 0l engines only 2 2l 2 5l version is available as seperate kit. 
															
													
									
																	Disa valve o ring size right i know there are plenty of forums but just hear me out i got a disa replacement however it didn t arrive without an o ring now i m desperately trying to find a suitable stand in as i have vacuum leaks and i m fairly sure that it s the valve. 
																	It will look something like this. 
																	Probably would give a 5 rating but it turns out there are two disa units for the x5 e53 m54. 
																	4 motorking d057rks 3 0l 01 06 bmw air intake flap adjuster unit disa valve repair kit and o ring. 
															
													
									
																	Mine has a wider orange o ring. 
																	O rings referenced as 136 137 138 139 should all work. 
																	Disa o rings for 325 330 engines have the following dimensions. 
																	Remove the two 2 torx screws to pull out the disa valve unit. 
															
													
									
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