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N12 vanos woes

7632 Views 31 Replies 4 Participants Last post by  mike1967, 
Cody4130
I have been trying to get my 2009 cooper project to run properly for a couple weeks. Upon first start the idle is lumpy but eventually smooths out. The vanos position and eccentric shaft position move around with revs and load as they should. Actual and commanded values are within 1 degree. The eccentric shaft value is around 23-24 at idle. (All these values are in degrees) I can hear a faint thunk sound then the value changes to a static 121 commanded 119 actual for the cam timing (both cams) and 176 commanded 171 actual for the eccentric values. Again these values never change, idle, WOT no change. Once this happens the car idles smoother but feels "flat" it revs slowly after 4000ish rpm. Feels like it's missing 20-25% of it's power. I have two scan tools both show similar findings. I get codes for the szl signal, DME tank vapor vent, 278D vanos. Vanos solenoids are new and I've tried switching them.

After significant research and forum lurking I am confident my timing process was right. As described by mike1967. I used a Mini specific locking tool, feeler gauges to take up any slack, and holding the camshafts in place with a wrench while doing the bolt stretch. New everything was used, cylinder head, gaskets, bolts, pistons, bearings, chain, tensioner and crank gears ect. Ect. I followed the torque processes. Once finished engine was rotated by hand 4 times and rechecked. Then ran down the road brought back and rechecked again.
I am unsure if a strange secondary problem is related in some way, my cooling fans will not turn on once the car reaches over 200F or even 220F. The fan itself works if I provide a direct 12v power or unplug the temp sensor. It's like the DME won't send the signal.

Included a current photo.
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Cody4130
Mike I finally got around to checking the oil pressure today, warm idle was around 45psi as seem in picture), 3k was about 70psi (was hard to get picture) , and 4.5k+ was 90-100psi.

I took it up the road and it is still surging like driving a bucking horse. Took a few photos of some values
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M
might have a answer to this i finally got in to a project i had in with same engine, same sort of thing was over heated and i changed the head on it but reused the camshafts and vvt assembly and rebuilt it,, so when i had rebuilt it i did not see that the spring fingers were not in the correct groove in the rear of the lift buckets , i will put a pic of how they should sit to the
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bucket you'll under stand when see it,
i found they kept coming off the groove then would sit on the rollers and cause a issue where the lift on valves and this would cause all kinds of issues on some cylinders, there is a special tool to place these spring fingers link below for a idea and boy its way to much money, i found two pairs of vice grips to keep spring curls down worked and sorted it,, when everything is correct you can rotate the inlet camshaft and have zero noises ,
link below for special tool
www.ebay.co.uk

Intermediate Lever Remover Install Tool Suitable FITS BMW Mini One Clubman VVT | eBay

Find many great new & used options and get the best deals for Intermediate Lever Remover Install Tool Suitable FITS BMW Mini One Clubman VVT at the best online prices at eBay! Free delivery for many products.
www.ebay.co.uk
looking at your diagnostics and smooth running's and number 1 cylinder ie gearbox end is different form the others would say either have same fault on 3 cylinders of a fault within cylinder 1,
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Cody4130
I decided to double check my rocker arms for proper orientation, even though they were assembled by the cylinder head shop and not me, and discovered cylinder 1 (Bottom of photo) had fallen off. I put it back on and refitted the valve cover. Idle was smooth. All my misfires went away but power delivery is still surging. Misfire count is 0 but watching the vanos numbers the intake numbers the actual and commanded get further apart when power surges, 30 to 40 degrees sometimes. Exhaust vanos numbers stay within a couple degrees. I'm going to try switching the solenoids. I also ordered two new ones in case these ones are comtaminated with metal shavings. Also
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changed the oil and filter.
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M
put a 27mm spanner on the inlet cam shaft if it free wheels ie can move then its faulty i have had issues with way to many of them to be honest, also found the after market ones are crap genuine only,, little tip buy them from a Peugeot main dealers as 207 fs or fw engine codes ie same gear and only £54 uk money bmw want for same part £360,, also if tensioner has locked up solid that can cause drag on the vanos and will prevent it turning and once again only fit a genuine tensioner and latest spec as latest one is a gentle spring and longer throw so much better pic below for the difference
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M
also make sure the springs sit in the square cut out on trailing edge and not further towards the middle roller if that makes sense
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Cody4130
Thanks Mike. I will try to turn it with a wrench and see if it moves easily. The tensioner I fitted was aftermarket and looks like the shorter one in your picture. I took it out to check and it seemed to be functioning fine. I can order the updated genuine one and swap them out.
The Vanos gears I used are the original ones from the engine 94k. I also checked the followers and the spring is placed in the groove as it should be.
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Cody4130
Update: Problem solved! I installed two new Vanos solenoids and changed the oil and filter. The car runs 100% now. Thanks for all the help.
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MickeyMini
Cody4130 said:
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Hi Cody4130, sorry to drop this in now, over a year since you posted, however can't help but notice the damage to the cylinder head. I guess that could have been done by a number of things - but one possible cause would be a valve seat dropping out, a pet topic of mine! Was there similar damage to the piston crown? I have added a picture of my partner's n12 after a valve seat dropped out.

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MickeyMini said:
Hi Cody4130, sorry to drop this in now, over a year since you posted, however can't help but notice the damage to the cylinder head. I guess that could have been done by a number of things - but one possible cause would be a valve seat dropping out, a pet topic of mine! Was there similar damage to the piston crown? I have added a picture of my partner's n12 after a valve seat dropped out.
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i got pet project at mo done same trick on a 2010-60 plate n16 with 87k on clock
Light Automotive tire Wood Circle Metal
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had head skimmed and new seat and guide and valve fitted , had it running for a few minutes other day and found oil pump solenoid faulty so just put a new in
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MickeyMini
mike1967 said:
i got pet project at mo done same trick on a 2010-60 plate n16 with 87k on clock View attachment 283089 View attachment 283090 View attachment 283091
had head skimmed and new seat and guide and valve fitted , had it running for a few minutes other day and found oil pump solenoid faulty so just put a new in
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Familiar sight Mike1867, luckily we only peppered the head and piston crowns, like you, replaced two valve seats, one missing and its sibling, plus four new pistons with rings and 3 piece oil control ring - oil consumption now back to zero! What's interesting is that the valve seat issue wasn't resolved with the development of the n16 engine.
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MickeyMini
mike1967 said:
i got pet project at mo done same trick on a 2010-60 plate n16 with 87k on clock View attachment 283089 View attachment 283090 View attachment 283091
had head skimmed and new seat and guide and valve fitted , had it running for a few minutes other day and found oil pump solenoid faulty so just put a new in
Click to expand...
A couple of Youtube clips from the 2012/13 period of an engine specialist repairing a couple of n12/14 cylinder heads with valve seat faults. From the commentator's voice over seems that repairing n12/14 cylinder heads was becomin a regular occurrence, even then, So.. not a recent problem, but one that is inherent to the cylinder head design/manufacture. Possibly the interference fit between valve seat and the valve seat recess isn't right.



Enjoy!
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M
yes it is , my theory is a couple of things one off these engine run to hot by design ie they are designed to use a controlled lean out to add power and reduce fuel use, bi product of this is heat over time this heat takes its toll, then theres cars that get over heated these tend to drop more than one seat out as the heat expands it all, another one is what i have one in for at present ie project where the seat cracks and drops out in bits , the running at 105c to 112c temps is a big reason behind it
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