I've been trying to help a friend swap the chain in his 2007 n14 R56 to fix a rattle it had at idle and on hard high rpm deceleration. We tried swapping just the tensioner, but that wasn't enough. This is this poor mini's second timing set, nothing about these guides were broken at all but the chain had certainly stretched when compared to the new one.

Anyway, we used the proper tools to lock the motor and camshafts in the proper position. We checked to ensure we had the crank locked in proper position by checking the pistons through the plug holes, as I discovered there's something else on the flywheel that can catch the lock pin. Used the dummy tensioner to set the proper preload on the chain before properly locking all three (new) tty bolts. After fixing the new chain tensioner, we rolled the motor over a few times by hand before checking the cam timing against the crank again before buttoning everything else up.

On the first start the car ran great, found and held a good low idle and no longer rattled so bad. The first drive found that the high rpm decel knock was gone as well, seems things were fixed. It ran great for a while and seemed to be on par with what it was before as far as acceleration and what not.

After checking to see if the power was still there, the car threw a light for half operating power mode while normal-driving at 30-40 in a high gear. It was able to continue the pace easily till the next stop where it idled fine for a few seconds or so. Upon trying to get the car going again though, there was no power at all so it easily stalled as the driver wasn't expecting it to behave that way. It hasn't started since then! I've tried to see if the car stored any codes, but wasn't able to find any. The code reader I have reads the mini specific codes, so it should have found it if it were there.

We've checked for spark and fuel, both are still firing though there's no way to tell if it's in time with everything else. After removing the valve cover I've found that both cams are still turning but the intake cam appears visually off from the exhaust cam. I can't tell if this is normal, or if something has slipped or if something else has malfunctioned. Perhaps I damaged the vanos solenoid while messing with the timing tensioner? The electrical connector appears intact at least...

On reinstallation we didn't install the VVT intake cam in any particular orientation, this snippet of the service manual says it is not critical. Is this a mistake? We didn't lock what I am assuming is a cam phasing unit down in any particular orientation to the exhaust cam or crankshaft.

http://www.scribd.com/doc/237316108/...-engine#scribd

Anyway, sorry for the book!

tl;dr
Does the intake VANOS cam gear need to be in a specific orientation when reinstalling in relation to the camshaft?
Will the engine ever stop running leaving the intake cam advanced or retarded from the initial timing position? Would it be normal for the motor to ever be at rest in a position the cam locking tools won't fit?
Can you break a VANOS solenoid and not throw a code?

Thanks guys!

 

I find it hard to believe you broke the VANOS solenoid, but try removing it and cleaning the screen. We have had multiple cars that thought their engine was out of time and all it was was the VANOS solenoid had buildup on the screens.

If you just timed the engine, it should be in time. Take it apart, use the proper locking tools at both cams and the crank, replace the single use hardware on the cam sprockets, and reassemble it. You do have a torque plus angle torque wrench right? That is a crucial tool in the job, you also want to make sure there is no oil in the threads of the cam bolts, as lubrication depreciates the torque value and can cause you to jump time. There is no keyway on the sprockets, they are a torque fit, improper torque can cause them to jump time.

 

Thank you for the reply.

I'll try taking the solenoid out to see if it got dirty, the thing is so close to the chain tensioner I thought I may have accidentally bent or deformed the thing.

I do not have a torque angle gauge, but since the bolts are all so easy to get to I've just been marking them and adding the torque angle that way. I did oil the threads on the bolts though, I could have sworn I read somewhere that it was critical to getting the correct torque spec. Are you absolutely certain that they are to be assembled with no lube? Lubrication commonly increases torque values, if there is less friction between threads then the bolt will obviously turn easier given the same force. Unless I've over-stretched the bolt, it should be torqued tighter.

http://www.enerpac.com/en-us/torque-tightening

These cars do have variable valve timing on the intake camshaft right? Is it not normal for the camshafts to be out of time with each other with only one variable camshaft?

Why oh why wouldn't they just key things? Argh!

 

So I just came back from the mini dealer, and a service tech at the shop was nice enough to answer a few questions for me. Picked up a new set of bolts too, since it looks like things have moved on me.

First, the VANOS unit is spring loaded and should automatically snap back to a zero position in the absence of oil pressure. This makes sense, and is why there's no alignment needed on the intake camshaft sprocket in relation to the camshaft

There is no procedure for cleaning the camshaft, crankshaft, or bolt threads before reinstalling. That is, oil on the threads should not bother the torque value enough to cause things to slip. Over-torqued or under-torqued bolts can cause slippage, of course.

What was recommended to me was to try and rotate the VANOS. That is, holding the gear but trying to rotate the cam flat. It should rotate some, yet automatically return on it's own. If it doesn't do so, something's up! Maybe it locked up and froze at a severely advanced position. I just hope no PTV action took place

So we've got a few things to try, I'll report back but still wouldn't mind more advice!

Thanks!

 

Well, it seems to be fixed. Instead of following the Bentley manual and lightly oiling the cam/crank bolts I cleaned them bare. IIRC the specs are 36ftlb+180 on the crank, 14ftlb+180 and 90 on the intake and exhaust respectively. I went to 45ftlb, 25ftlb and added 15deg everywhere. I have cheap torque wrenches, but I've checked them against a beam type wrench all across the range. I trust them to assemble my own motors, at least.

I was not able to get the VANOS unit to rotate and snap back, I even welded up a little tool to hold the sprocket while I worked the cam flat using 1/4" bar stock. A new one is more than a few car payments, so it's lucky it's not bad apparently. We ran the car through the revs for an hour last night and it's still running with no lights. Still seems to keep up the same with my car, power is still there. I wish I could find a way to check for cam advance in OBD2 readers, anyone know if the coding tools can read live data like that?

 

so you over torqued everything ? is that ok or will the bolts be weaker from over stretching ?

 

That is a possibility, but I don't think I've stretched them too much.

Seemingly every other part on the car has broken since then, but the valve timing isn't one of them luckily!