[doughboy]

Originally Posted by stlb5

I have a 19 with 40K and I can hear it on mine. My basic takeaway from all of this is to live with it until it's time to do the valve cover gasket. Having done that job before, I'm not itching to do it (let alone pay for someone else to do it), for a start up tick that goes away quickly and doesn't hurt anything.

My shop only charged 3 hours labour and £75 in parts to fix it, and changed the spark plugs for free while they were at it.

Not such a big job.

It will only get worse if it's loose and end in valve train wear, or ultimately a nasty failure. Mine soon progressed to a warm knock that was bad enough for people to say wtf is that?

[bitcore]

Originally Posted by doughboy

No serious I can't hear any tapping on the cold start, only loud exhaust rasp. Can you video cold start with bonnet open and camera near engine?

The hardest bit PITA is getting the cam cover off and back on without causing any oil leaks afterwards. The thinn rubber gaskets try to fall out of the cam cover when you turn it over to re-fit (try grease to hold it in place) if even one small bit of the gasket gets trapped or cut you will have serious oil leak problems.

I wouldn't change any lifters unless you think they are faulty. Maybe do some other maintenance like new spark plugs?

Once you got the cover off, changing the 15x cam ledge bolts is easy bit one at a time.

You can't re-torque them - there is no final torque setting as they are TTY stretch bolts, so they are stretched already and cannot be re-used.

I'm not sure of the tightening spec (your shop will need BMW workshop guide). But it will be a torque plus degrees turn, i.e. 30nm + 90degrees.

Whenever you see this you know it is TTY single use bolts.

All the parts from BMW only.

This is certainly interesting.

So, my dealer had to create a TC case, whereby photos of the oil filter housing, oil filter, and an audio clip of the noise were requested by BMWNA - to get the warranty work approved. The "case concluded to re-torque exhaust camshaft. Tech followed REP: 11 31 028"

On my service report, the bolts were retorqued. On the parts list on the service report were only a set of injector decoupling elements and seals, valve cover gaskets, and timing chain tensioner seal. The only bolts replaced were the two collar screw bolts which holds the camshaft gear to the camshaft. No mention of the 15x cam ledge bolts.

• 6x - 13-53-7-591-006 - Gasket Ring (injector o-ring)
• 6x - 13-63-7-577-649 - Decoupling element (injector de-couplers)
• 3x - 11-12-7-589-830 - Gasket (valve cover spark plug well gaskets)
• 1x - 11-12-7-587-804 - Profile-Gasket (valve cover gasket)
• 2x - 11-27-7-524-954 - Collar Screw (camshaft sprocket bolt)
• 1x - 11-31-7-535-251 - Gasket Ring (timing chain tensioner crush washer)
• 1x - 82-14-1-467-704 - Antifreeze

I'd agree with doughboy. If these bolts are aluminum - and they sure look like they are in part photos, I understand that these kinds of bolts should be replaced. It's not known to me what the factory torque spec is, if it was followed during manufacture, and if the "REP: 11 31 028" repair procedure calls for a torque + angle or just a torque value.

I've yet to raise this with my SA, considering that the noise is indeed fixed now. I'm more curious about what the the official BMW repair procedure dictates, as I am inclined to believe they followed said procedure. I doubt my dealer's service depot is trying to pocket $30 on a warranty job by skipping out on replacing bolts if procedure says they should have.

Does anyone have any inside info on what "REP: 11 31 028" may be?

[doughboy]

Dont know what the REP code is, but there was a PUMA issue raised but don't know about a formal BMW REP (repair?) procedure.

In the UK the indy shop I use knew about the BMW UK notice, they'd done it several times on other S55 and they fixed by replacing and torquing all 15 bolts, which are just approx £2 each.

My oww copy of ISTA work procedures section isn't working, so if anyone has ISTA then the bolts torque should be on there.

I found for N54 engine same part is 8nm +60deg.

[Fred Conoway]

REP 11 31 028 are the repair instructions for removing and installing / replacing exhaust camshaft for the S55 as per ISTA

[doughboy]

If you have ista can you find the tightening spec for the cam ledge bolts? 15 off?

I have ista but my service instructions never seem to work.

[aptwave]

Originally Posted by doughboy

If you have ista can you find the tightening spec for the cam ledge bolts? 15 off?

I have ista but my service instructions never seem to work.

It's 8nm torque + 60deg angle.

Just did this job by myself, basically you need to follow 11 12 040 REP procedure from ISTA called "Removing and installing all ignition coils and injector wells", this will give you full access to all 15 bolts, as some of them covered by injectors wells.

For this job you need special tool to remove and install injectors, check some youtube videos on n55/s55 for solutions. You can even take them out using reverse hammer, so it is your choices how to do that part.

I used special tool from JTC (JTC-4336), which is bad in my opinion and would not recommend it, unable to use it for installation, it can't handle pressure when you install injectors, so I just pushed them with my hand and using original holding plates, carefully turning bolt holding injectors in place and they pop-in.

After that, you need to replace all 15 bolts one by one, torque to 8nm + 60deg each. I can't see instruction in ISTA to replace bolts, just insert them dry and into clean threaded holes, "There must be no adhesive residues in the cylinder head threaded holes". In my case, old bolts were all in the oil, so I decided to replace them instead of cleaning, as they are pretty cheap.

Usually, you have instructions to replace or renew bolts in the torque specs table, but for those 15 I don't see them, only insert them dry and torque + angle.

After that you're good to assemble everything back, but follow instructions and replace injectors wells seals (3 pieces), injectors seals and decoupling elements (6 pieces + 6 pieces, for every injector). Make sure to compress seals before inserting injector back into the engine, check youtube videos for DIY how to do that or use special tool from ISTA (or JTC-4388, which works good in that case, can recommend it, but you need only few items from it, so price is high). Replace head cover seals, fuel rail decoupling elements(4 pieces), tighten it in correct sequence and best if you use torque keys here too, put your coils back, connect cables, etc.

Basically assemble everything in reverse order, follow ISTA, replace seals required and use correct torques. It can be done at home with no probs, and with little to zero special tools.

If someone need torques values or REP instructions related to this job, I can print them from ISTA and share.

[bitcore]

Originally Posted by aptwave

It's 8nm torque + 60deg angle.

....

If someone need torques values or REP instructions related to this job, I can print them from ISTA and share.

Thanks Aptwave,
Yes printout PDFs of the relevant instructions would be excellent for others who do not have ISTA.

[doughboy]

Think I said on other thread, be aware you must replace the 15 off ledge bolts, they are TTY stretch.

If BMW didn't make it clear in the REP it must be an error.

Anyhow, i checked the invoice from my indy and they and also removed the cam, checked the journals for wear then replaced all 15 bolts in the process.

They charged 4.5hrs labour all in.