Test and Clean VANOS Solenoids – BMW VANOS Symptoms

Hey guys and welcome back to the SimpleCarGuy channel. In this video we will discuss common symptoms of a bad solenoid, see how we can test one at home and how to clean it.

Ever since the early 90s, a lot of BMW engines have been using the VANOS system to adjust the valve timing on the fly. This gives the engine more power over the rev-range and for that reason in general, we like variable timing on engines. We get low end torque and high end horse power, very similar to VTEC on Honda engines. The design has changed over the years, starting with single VANOS system used in the 90s, dual VANOS system used in early to mid 2000s as well as the famous n54 engine that was in production until 2010 and of course Dual-VANOS with VALVETRONIC that I have in my N55 engine that was released in 2009 and is still used today.

Now that we know a little bit of history, let’s take a look at how to actually diagnose a bad VANOS solenoid. A lot of the times, the symptoms are not drastic, so it can be difficult to tell, but usually you’d look for things like loss of low-end torque or power in high revs, slow response or inconsistent idle or even poor fuel economy. Some of the more noticeable items could be rough idling; especially, on cold starts as well as long cranking. Of course, if it’s bad enough, the car will go into limp home mode and you’ll normally get codes related to Camshaft Position or VANOS specific codes. If you suspect the solenoid might be fault on your car, there are ways of testing it. This isn’t something you’d see a dealer do, but it may help you troubleshoot your engine issue. Of course, if the issue is intermittent, this method does not guarantee that it will always work, but it’s an easy way to detect a bad one.