Quote:
Originally Posted by M_Three
Alright. Looks like this thread got lots of great discussions going. Lets go another direction now.
Ok.. Now about me. I am the Manufacturer Rep for Launch Scanners for the state of Florida. We have some pretty good coverage in the European vehicles. Nearly factory coverage. So needless to say, its a great tool on BMW.
So yesterday i was in a Hyundai dealer speaking to one of the techs there about getting a scanner from his Matco dealer. In talking to him he told me that they have a major recall on ROD BEARINGS going bad on newish vehicles. The fix is to replace the entire long block.. So I asked him how they diagnosis the failure. He said that they put a listening device in the oil dipstick tube and measure the noise level. PRETTY COOL..
This got me thinking. All modern engines have their own listening devices internal. The Knock Sensor... So what I am going to do is hook up one of my Launch Scanners and with the engine on first start I am going to look at the Knock Sensor in Graph mode to see if it picks up any low end noise. It just might be a way to diagnose these types of problems without relying on actually trying to hear it over the already loud engine. It might also be the reason many M3 owners say that their car felt sluggish before they replaced the bearings. Just might be the knock sensor listening to the low end knock and retarding the timing. It's worth me doing a test.
Photos to follow later today. Should be fun.
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I don't believe the s65 has actual knock sensors (uses ionic current knock sensing), but I'd be interested in hearing more about this on the s62/s54 (which have a bunch)!