Vanos Moan

2002 M3 Coup with 104xxx on the clock. I noticed a very subtle moan or reverberation between rpms 1700-2000 when the engine is warm and under normal or light acceleration. It seems to go away when I go full throttle and isn't there when the engine is not up to full temp, which leads me to believe my vanos is getting angry. Just started after a highway run while not fully warm.... Stupid, I know. Anyhow, has anyone experienced this or is this not the vanos? No lights or other symptoms to report. Differentail diagnosis includeds anything related to the oil system. What do you guys think? Thanks for the replies!

take it to an indy shop and have the motor taken apart and checked, thats how i found mine was on its way out, and if it IS your vanos, Drvanos.com is the best place to get one, they even refund you 400 for your old one.

Originally Posted by DrGSXR750

2002 M3 Coup with 104xxx on the clock. I noticed a very subtle moan or reverberation between rpms 1700-2000 when the engine is warm and under normal or light acceleration. It seems to go away when I go full throttle and isn't there when the engine is not up to full temp, which leads me to believe my vanos is getting angry. Just started after a highway run while not fully warm.... Stupid, I know. Anyhow, has anyone experienced this or is this not the vanos? No lights or other symptoms to report. Differentail diagnosis includeds anything related to the oil system. What do you guys think? Thanks for the replies!

Its real easy to look over your self. Search the forum as well as m3f, also Google is your friend. There are many components to the vanos and it doesn't just "go out" as a whole assembly. The most common failure which yeilds an audible warning are the bolts on the intake Cam sprocket. These are prone to coming loose and or shearing. The bottom line is don't jump to conclusions. The S54 is noisy as hell, including the vanos.

Yea I know and that's what I'm hoping but it's definitely a new sound. I'm going to check the oil filert for the vanos tomorrow but I'm not sure it's the bolts because there is no rattle only a reverberation at specific rpm. Thanks again for the reply gentlemen! I owe you my next paychecks which, as a resident, is about nil lmao.

Originally Posted by DrGSXR750

Yea I know and that's what I'm hoping but it's definitely a new sound. I'm going to check the oil filert for the vanos tomorrow but I'm not sure it's the bolts because there is no rattle only a reverberation at specific rpm. Thanks again for the reply gentlemen! I owe you my next paychecks which, as a resident, is about nil lmao.

Haha no worries we are all here to contribute. Even if its not a traditional rattle I would take a peak for piece of mind. I had a similar situation and listing closely to the motor I was certain it was from the vanos bolts. I went ahead and replaced them while I was at it but, the problem was a 20.00 idler pulley. These pulleys don't last long as it is plastic and a single sealed race bearing. Its a cheap design IMO... If it has lateral play spins freely, and sounds like a skateboard wheel, it needs to be replaced. Our cars have two one for the AC pump circuit, and the second is fan water pump, and alternator. In my case the later of the two was shot. Good luck, and let us know what you find.

Originally Posted by NICKBRUM

Haha no worries we are all here to contribute. Even if its not a traditional rattle I would take a peak for piece of mind. I had a similar situation and listing closely to the motor I was certain it was from the vanos bolts. I went ahead and replaced them while I was at it but, the problem was a 20.00 idler pulley. These pulleys don't last long as it is plastic and a single sealed race bearing. Its a cheap design IMO... If it has lateral play spins freely, and sounds like a skateboard wheel, it needs to be replaced. Our cars have two one for the AC pump circuit, and the second is fan water pump, and alternator. In my case the later of the two was shot. Good luck, and let us know what you find.

Is it a bia to get in there and check those idler pulley's? and how do you determine if they are bad? just take the belt off and see if they have any lateral play or noise?? The more I listen to it the more I think it might be a pulley going out. Still going to check and upgrade the bolts though for piece of mind. Thanks again for your replies.

Pulleys aren't that bad to get to. There are DIY's. A good pulley will not have any play and will have some resistance when spun. If it spins freely like wheels on a skateboard then it's toast.

If you don't know when they were replaced it's probably worth going ahead and replacing all the pulleys and belts anyway.