I believe I also have a camshaft bolt issue

[pokeybritches]

Do we know what build dates are affected? What's your build date sirmalloc?

[sirmalloc]

Originally Posted by O-cha

Old ones hex bolts?

Yeah...are the new ones different?

[sirmalloc]

Originally Posted by pokeybritches

Do we know what build dates are affected? What's your build date sirmalloc?

04/2006

[O-cha]

Originally Posted by pokeybritches

Do we know what build dates are affected? What's your build date sirmalloc?

I think it's actually basically all s54s.

Originally Posted by sirmalloc

Yeah...are the new ones different?

New ones should be torx bolts, doesn't mean much though.

[Nhopkins1394]

This is a problem only found on the ///M engine, right?

[onebluemcm]

Originally Posted by sirmalloc

I thought it was odd they said they needed to lift the engine. At any rate, here's the pictures:

Maybe they had to lift it to get the needed clearance on te VANOS unit with the tight clearance? Did you ever find out more about them lifting the engine?

I hope it's not needed to do this repair - just more things for them to potentially mess up...

[O-cha]

Originally Posted by onebluemcm

Maybe they had to lift it to get the needed clearance on te VANOS unit with the tight clearance? Did you ever find out more about them lifting the engine?

I hope it's not needed to do this repair - just more things for them to potentially mess up...

That's most likely, but shouldn't be necessary. The proper way is to loosen the vanos, use the solenoid to put the pistons into a position you can unscrew them, then retard then again so you can pull it out.

[onebluemcm]

Originally Posted by O-cha

That's most likely, but shouldn't be necessary. The proper way is to loosen the vanos, use the solenoid to put the pistons into a position you can unscrew them, then retard then again so you can pull it out.

This is good to know....I may mention it if I end up having this done. Can the pistons be moved by hand? I thought I read that somehwere on all the recent forum activity on this subject.

BTW, is there one major symptom that is present with this issue? I'm a little unclear on that - seems like a substantial number of bolts could be entirely broken and you wouldn't know it.....true?

[O-cha]

Originally Posted by onebluemcm

This is good to know....I may mention it if I end up having this done.

BTW, is there one major symptom that is present with this issue? I'm a little unclear on that - seems like a substantial number of bolts could be entirely broken and you wouldn't know it.....true?

Rattling, I'll go into a little depth here, It's really hard to explain without drawing pictures

But basically the bolts we are talking about bolt a metal disk which has splines on the inside to the camshaft. This is how the camshafts are spun. So when the bolts get loose there's going to be play there and it should make noise, and when they finally break nothing is spinning the camshafts anymore.

[onebluemcm]

Originally Posted by O-cha

Rattling, I'll go into a little depth here, It's really hard to explain without drawing pictures

But basically the bolts we are talking about bolt a metal disk which has splines on the inside to the camshaft. This is how the camshafts are spun. So when the bolts get loose there's going to be play there and it should make noise, and when they finally break nothing is spinning the camshafts anymore.

And then there is rapidly ensuing massive destruction. Is any rattling normal with S54s? My M3 did some, but maybe it had loose cam gear bolts too.... I've been told that they can do some rattling normally. Mine does some during warm up, and always has some rattle to it in the 3000 +/-200 RPM range.

Can the VANOS pistons be moved by hand? I thought I read that somehwere on all the recent forum activity on this subject.

[O-cha]

Originally Posted by onebluemcm

And then there is rapidly ensuing massive destruction. Is any rattling normal with S54s? My M3 did some, but maybe it had loose cam gear bolts too.... I've been told that they can do some rattling normally. Mine does some during warm up, and always has some rattle to it in the 3000 +/-200 RPM range.

Can the VANOS pistons be moved by hand? I thought I read that somehwere on all the recent forum activity on this subject.

I wouldn't say the s54 rattles, adjectives are very hard to convey though.

Pistons can't really be moved by hand.

[onebluemcm]

Originally Posted by O-cha

I wouldn't say the s54 rattles, adjectives are very hard to convey though.

Pistons can't really be moved by hand.

Agreed on the adjectives - if you were closer (meaning, within a few hundred miles) I'd bring it to you to have you take a gander at it. Thanks for your expertise around here, very helpful.

So, how do I go about finding an "S54 expert" in my area/region? I know there are guys by the name of Fletcher Made Horsepower that built engines for my friend that ran a Z4M in Koni and for Turner - should I be looking up a place like that?

[O-cha]

Originally Posted by onebluemcm

Agreed on the adjectives - if you were closer (meaning, within a few hundred miles) I'd bring it to you to have you take a gander at it. Thanks for your expertise around here, very helpful.

So, how do I go about finding an "S54 expert" in my area/region? I know there are guys by the name of Fletcher Made Horsepower that built engines for my friend that ran a Z4M in Koni and for Turner - should I be looking up a place like that?

If they have built s54s for racing series then they would have to have both the tools and experience to do what you need.

[AtoB]

Originally Posted by O-cha

Rattling, I'll go into a little depth here, It's really hard to explain without drawing pictures

But basically the bolts we are talking about bolt a metal disk which has splines on the inside to the camshaft. This is how the camshafts are spun. So when the bolts get loose there's going to be play there and it should make noise, and when they finally break nothing is spinning the camshafts anymore.

here is a pic to help, with a couple bolts removed... happened to my old M, but was quickly fixed.

[O-cha]

Originally Posted by AtoB

here is a pic to help, with a couple bolts removed... happened to my old M, but was quickly fixed.

Ugh, I have the pictures I just didn't want to do it, I guess I will now. Hold on.

[O-cha]

Ok, so where the red line is indicates the outer edge of the part I'm about to talk about. basically this piece is bolted to the camshaft and NOTHING else is bolted to it. The way it is in that picture you can actually pull off the timing gears/timing chains without unbolting anything else.

Now the green circle is splined on the inside, it's part of the piece bolted to the camshaft. There is a splined shaft that goes into this and is the only thing that turns the camshaft. So when the bolts break that piece circled in red just starts spinning instead of the actual camshaft.

When they are loose its going to rotate forward and back a little and eventually cut into the bolts like we have seen. And yes they cannot come out completely because there is a thrust washer there.



You can see the splined shafts that go into the camshaft as well as what spins them. what spins the splined shaft bolts to the outer bolts in the upper picture. The second set of splines though are helical, so when the shaft foes in and out it is forced to spin a little bit in relation to the timing gears, which is what creates the change in cam timing.

[onebluemcm]

Great diagrams and explanation. Huh, all along I thought the 6 allen bolts, the ones failing, were the bolts that physically connected the cam gear directly to the cam shaft. I have not come across a fully exploded diagram of all the parts involved, which is probably why I don't/didnt fully understand it. I thought that the 6 hex bolts held the VANOS hub to the cam gear some how and allowed for the variablilty in the cam timing as the helical gears were adjusted by the system. The helical gear portion does mesh with this hub part, correct?

[O-cha]

Originally Posted by onebluemcm

Great diagrams and explanation. Huh, all along I thought the 6 allen bolts, the ones failing, were the bolts that physically connected the cam gear directly to the cam shaft. I have not come across a fully exploded diagram of all the parts involved, which is probably why I don't/didnt fully understand it. I thought that the 6 hex bolts held the VANOS hub to the cam gear some how and allowed for the variablilty in the cam timing as the helical gears were adjusted by the system. The helical gear portion does mesh with this hub part, correct?

Helical gears mesh with the parts you can see in the lower diagram, and the straight splines mesh with the part bolted to the camshaft. The helical part is bolted to the timing gears and the straight splines bolted to the camshaft are only attached to the rest of the car through the splined shaft.

[onebluemcm]

My final thread-jack question, maybe it's a little pertinent to the OP questions. If the cams basically need to be retimed with this fix, is this a reasonable time to consider differnt cams for the car? I've read alot of debate on cams - looking for opinions as to whether or not they are even "worth it" for the stock S54.

Is it really that much more work to swap the cams at this point? With the engine management on mine, an '07, can CSL cams, for example, even be run at all, or do they require modification of the DME? I might have a fair deal on CSL cams so the thought crossed my mind. Wouldn't want to do it if it is a mod fraught with headaches or if the money is better spent elsewhere, but then again, there may not ever be as good a time to do cams as when having the cam bolts checked/replaced.....just throwing this out there for thoughts.
Thanks again.

[O-cha]

Originally Posted by onebluemcm

My final thread-jack question, maybe it's a little pertinent to the OP questions. If the cams basically need to be retimed with this fix, is this a reasonable time to consider differnt cams for the car? I've read alot of debate on cams - looking for opinions as to whether or not they are even "worth it" for the stock S54.

Is it really that much more work to swap the cams at this point? With the engine management on mine, an '07, can CSL cams, for example, even be run at all, or do they require modification of the DME? I might have a fair deal on CSL cams so the thought crossed my mind. Wouldn't want to do it if it is a mod fraught with headaches or if the money is better spent elsewhere, but then again, there may not ever be as good a time to do cams as when having the cam bolts checked/replaced.....just throwing this out there for thoughts.
Thanks again.

Depends, one you'll need a tune, two technically you are supposed to replace all the rocker arms when you replace the cams, which is going to require more work, since the engine would have to be lifted out a foot.

[onebluemcm]

meh, perhaps there are other, easier and possibly better things to do - headers, etc..... Will have to give it some thought. Engine has to be raised to slide out the rods that the rocker arms pivot on - didn't think of that. Yeah, if not for that little part, wouldn't be too bad of a job. They recommend matching new rocker arms with new cams so you don't have unmatched wear patterns? In reality, is this an issue?

[O-cha]

Originally Posted by onebluemcm

meh, perhaps there are other, easier and possibly better things to do - headers, etc..... Will have to give it some thought. Engine has to be raised to slide out the rods that the rocker arms pivot on - didn't think of that. Yeah, if not for that little part, wouldn't be too bad of a job. They recommend matching new rocker arms with new cams so you don't have unmatched wear patterns? In reality, is this an issue?

That's exactly right, and yes and no. It's hit or miss, but it's a pretty big miss when its a miss. I'd say more hit then miss, but if it was me I would change them, but then again it's just easy and free for me, lol.