VANOS oil pump drive tabs, 1 more question!

G550PLT · Wed, Nov-24-2010, 11:20:53 AM

So as some of you may know.. my VANOS pump drive tabs on the exhaust cam gear both broke about a month ago..53k on the car. The bill was pretty steep, and of course that part alone was almost $1k. I was just laying in bed waking up this morning savoring the thought of the drive to go get the am coffee in my freshly repaired beautiful M3... when a thought hit me.

I felt "Lucky" that when my tabs broke.. I didn't have any collateral damage... and just now i realized.. the $1k part I replaced.. the stupid part that caused it all.. the part that has the potential to cause the grenade-ing of the whole top end.. well .. its the same EXACT part number as the faulty one wasn't it?

Correct me if Im wrong, but BMW didn't improve that part did they? So now... the peace Iv'e been feeling lately.. knowing that all was well under the valve cover ..etc... is GONE! I mean.. basically all I did for all that money was buy myself another 50k miles or maybe LESS?

Please somebody tell me Im wrong.. this thought just killed my morning!

excessive · Wed, Nov-24-2010, 04:05:46 PM

no one really knows why the tabs fail, but it seems that those gears are cast formed, instead of CNC milled like most cam gears. I guess this is just the inherent weakness coupled with a flawed design. ( the tabs should have been made thicker , etc.)

At first we thought the tabs breaking was related to other vanos issues ( like loose bolts) but it seems the two failures are not related to one another.

G550PLT · Wed, Nov-24-2010, 05:31:25 PM

certainly seems like a design flaw.. I think I had a broken tab for a while.. one of the tabs was shiny where it broke.. the other was oil colored.. like it had been that way for a while. I bet there are many more cars with broken tabs than we know, with just one tab driving the pump..

benzthis · Wed, Nov-24-2010, 07:28:01 PM

Quote:

Originally Posted by excessive

no one really knows why the tabs fail, but it seems that those gears are cast formed, instead of CNC milled like most cam gears. I guess this is just the inherent weakness coupled with a flawed design. ( the tabs should have been made thicker , etc.)

At first we thought the tabs breaking was related to other vanos issues ( like loose bolts) but it seems the two failures are not related to one another.

If someone can cnc mill these cam gears and tabs,it would really make these engines a lot more reliable.and I'm sure many here would buy these for peace of mind.

G550PLT · Wed, Nov-24-2010, 10:02:52 PM

I agree! I paid $951 for the OEM part.. Im sure if you sold the parts at that price you'd have to make a profit! I know Id gladly take mine back apart to put a better part in there..

excessive · Thu, Nov-25-2010, 01:55:12 AM

Quote:

Originally Posted by benzthis

If someone can cnc mill these cam gears and tabs,it would really make these engines a lot more reliable.and I'm sure many here would buy these for peace of mind.

i would be 1st on the list to buy a CNC machined one, and I am quite sure they could be made for less than $951

kidrobot · Fri, Nov-26-2010, 12:50:52 AM

Bump, I'd be in.

sleeks · Fri, Nov-26-2010, 01:57:51 AM

I would too. If I am going to do the bolts, might as well have this done when the car is open.

Cloudsurfer · Fri, Nov-26-2010, 03:43:06 AM

I'll have to run this by my machine shop friend.....

G550PLT · Fri, Dec-10-2010, 08:32:38 PM

Quote:

Originally Posted by Cloudsurfer

I'll have to run this by my machine shop friend.....

Any word from your friend? Im not a metallurgy expert .. so would machined cnc aluminum be stronger than a cast steel part? (I think its cast right?)

Wed, Nov-24-2010, 11:20:53 AM	#1
G550PLT Registered User Join Date: Nov 2009 Posts: 544 Reputation: 0 Location: Lake Worth	VANOS oil pump drive tabs, 1 more question! So as some of you may know.. my VANOS pump drive tabs on the exhaust cam gear both broke about a month ago..53k on the car. The bill was pretty steep, and of course that part alone was almost $1k. I was just laying in bed waking up this morning savoring the thought of the drive to go get the am coffee in my freshly repaired beautiful M3... when a thought hit me. I felt "Lucky" that when my tabs broke.. I didn't have any collateral damage... and just now i realized.. the $1k part I replaced.. the stupid part that caused it all.. the part that has the potential to cause the grenade-ing of the whole top end.. well .. its the same EXACT part number as the faulty one wasn't it? Correct me if Im wrong, but BMW didn't improve that part did they? So now... the peace Iv'e been feeling lately.. knowing that all was well under the valve cover ..etc... is GONE! I mean.. basically all I did for all that money was buy myself another 50k miles or maybe LESS? Please somebody tell me Im wrong.. this thought just killed my morning!

Fri, Nov-26-2010, 01:57:51 AM	#8
sleeks Registered User Join Date: Feb 2005 Posts: 3,661 Reputation: 0 Location: Northern Suburbs/Chicago	I would too. If I am going to do the bolts, might as well have this done when the car is open. __________________ MY02 ///M3 - Steel Grey/Black I am on my third E46 M3....yes, I am crazy Gone: 03 Tiag/Black 04 Silver Grey/Black

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Wed, Nov-24-2010, 04:05:46 PM	#2
excessive Registered User Join Date: Aug 2006 Posts: 705 Reputation: 0	no one really knows why the tabs fail, but it seems that those gears are cast formed, instead of CNC milled like most cam gears. I guess this is just the inherent weakness coupled with a flawed design. ( the tabs should have been made thicker , etc.) At first we thought the tabs breaking was related to other vanos issues ( like loose bolts) but it seems the two failures are not related to one another.

Wed, Nov-24-2010, 05:31:25 PM	#3
G550PLT Registered User Join Date: Nov 2009 Posts: 544 Reputation: 0 Location: Lake Worth	certainly seems like a design flaw.. I think I had a broken tab for a while.. one of the tabs was shiny where it broke.. the other was oil colored.. like it had been that way for a while. I bet there are many more cars with broken tabs than we know, with just one tab driving the pump..

Wed, Nov-24-2010, 10:02:52 PM	#5
G550PLT Registered User Join Date: Nov 2009 Posts: 544 Reputation: 0 Location: Lake Worth	I agree! I paid $951 for the OEM part.. Im sure if you sold the parts at that price you'd have to make a profit! I know Id gladly take mine back apart to put a better part in there..

Fri, Nov-26-2010, 12:50:52 AM	#7
kidrobot Unregistered User Join Date: Jan 2010 Posts: 1,310 Reputation: 0 Location: Florida	Bump, I'd be in.

Fri, Nov-26-2010, 03:43:06 AM	#9
Cloudsurfer Registered User Join Date: Oct 2010 Posts: 481 Reputation: 0	I'll have to run this by my machine shop friend.....