Power loss through 4000rpm - The Unofficial BMW M5 Messageboard (m5board.com)

JetDehr · 3rd October 2004, 03:35

I have a 2000 M5 28,000 miles, with all Dinan upgrades (stage 5 programming, throttle bodies, velocity stacks, Intakes, Meters, headers, exhaust) as well as the supersprint x-pipe. My problem is that I have noticed a power loss as it is sweeping through 4000 rpm. Typically in third gear and above. It is still making power but it plateaus instead of building as it should in the power band. It feels like timing might be being pulled out as it gets into this rpm band at WOT. If I back off and then roll the throttle on again but not to WOT it seems to pull harder than it does at WOT. I'm thinking either it's an over sensitive knocksensor or possibly something else odd like throttle bodies not in sync with where they should be? VANOS problem? Cam timing sensor problem? Weak coil(s)? The engine has strong compression, oil pressure is no problem. Something that may be related is that it runs rough until warmed up as if it is not firing every ignition cycle. Any suggestions? Anybody experienced anything similar?
If you can respond to the post and my personal email to ensure I get the reply that would be great, jetder@aol.com Thanks for your help in advance,
Thor

ACTECH · 22nd October 2004, 03:37

Quote:

Originally Posted by JetDehr

I have a 2000 M5 28,000 miles, with all Dinan upgrades (stage 5 programming, throttle bodies, velocity stacks, Intakes, Meters, headers, exhaust) as well as the supersprint x-pipe. My problem is that I have noticed a power loss as it is sweeping through 4000 rpm. Typically in third gear and above. It is still making power but it plateaus instead of building as it should in the power band. It feels like timing might be being pulled out as it gets into this rpm band at WOT. If I back off and then roll the throttle on again but not to WOT it seems to pull harder than it does at WOT. I'm thinking either it's an over sensitive knocksensor or possibly something else odd like throttle bodies not in sync with where they should be? VANOS problem? Cam timing sensor problem? Weak coil(s)? The engine has strong compression, oil pressure is no problem. Something that may be related is that it runs rough until warmed up as if it is not firing every ignition cycle. Any suggestions? Anybody experienced anything similar?
If you can respond to the post and my personal email to ensure I get the reply that would be great, jetder@aol.com Thanks for your help in advance,
Thor

kallijaxl · 27th June 2008, 22:44

hy there i had similar problems with mine m5 2000 model.i toke it to my bmw mechanic and he told me that camshaft sensor was broken.it could also be the oxygen sensors or vanos.just let the bmw mechanic check it out.it takes half an 1.camshaft sensor is very cheap but the vanos is expensiv very.if it is vanos you shut check if you can get a vanos repair kit much cheaper.i was very lucky my friend is a car freak and his friend is going to buy it for me in germany very cheap

MarkQC · 28th June 2008, 09:43

Quote:

Originally Posted by kallijaxl

.......you can get a vanos repair kit much cheaper.i was very lucky my friend is a car freak and his friend is going to buy it for me in germany very cheap

...any details on this cheap vanos repair kit?