Issues after VANOS rebuild

[mrscalex]

Looks like I scuffed up something when I did my VANOS seals.

Car fired up fine but was lumpy. No nasty noises from the engine. Just lacking in power and pulsing from the exhaust. Didn't think too much of it at first as I know it needs to get rid of trapped air. But 5 mins later still not right. Diagnostics telling me error 104 intake jammed or blocked. And corresponding error on the exhaust. My initial thought was a dodgy solenoid but I can't believe it would happen on both sides at once.

Engine now turns over but won't start.

Can't quite figure why if the VANOS wasn't working the engine was running so bad. Previously I had a faulty exhaust CPS which was causing the VANOS to be disabled and run in default positions. Engine ran fine like that.

Things worth knowing:

• VANOS rebuild itself went fine. Though I was surprised the pistons weren't a tighter fit. I used a good quality make X8R. And did the piston resizing as instructed
• My torque wrench wasn't clicking where I felt it should (10Nm) when I refitted the piston to camshaft bolts. So I did this by hand. It could therefore be too tight or not tight enough
• I used the VANOS unit itself from a donor engine that I've never run. So I can't be 100% certain it didn't have issues but all looked fine and it seems unlikely
• I used one original solenoid from the car and one from the donor VANOS so I had the two with the least rust. In other words one was an unknown quantity.
• I made a cock-up initially and put the spring on the intake side. I got as far as turning the engine over to circulate oil with the coils out. It turned over for about 0.5 sec then the battery died on me. So I guess I might have done some damage there but when I took it back apart nothing to suggest I had. I'm hoping a dodged a bullet as the battery failed on me

I've got no problem with taking it all apart again. After the spring issue I had it all apart and back on in around 45 mins. But no real point until I gather some ideas about what it is that needs fixing.

 

[mrscalex]

Captain d*ckhead realised he'd put the solenoid pistons in the wrong way. I don't think that would be helping...

The inlet has been swapped. But I need to find a suitable wrench to get the exhaust solenoid off - not easy without a short stubby 32mm wrench, very long socket or large grips none of which I have.

 

[Jonno Bee]

Thanks Rob for your honest appraisal. I'll try not to chuff up the single vanos fiited to mine when I do it!
Hope you sort it.

 

[mrscalex]

Thanks Rob for your honest appraisal. I'll try not to chuff up the single vanos fiited to mine when I do it!
Hope you sort it.

It's easier than you would imagine getting things round the wrong way. The main pistons should stay in the same bore for good measure (only relevant for double VANOS). The spring will physically fit in either piston (again only double VANOS) and the solenoid piston(s) will go back in either way. There's loads of how tos with photos but I think the most appropriate way of putting it is it's easy to read a map upside down.

 

[Stevo7682]

Doesn't matter how many years repairing cars you have behind you easy to have a moment and do something wrong the experience bit comes in when you realise and what you then do to remedy the issue good to see that you know what has happened therefore have a fix .
I also like the fact that you have posted what has happened on here shows others that unless you take proper care these sorts of jobs can run into issues as I think sometimes these jobs when posted ( by competent people) can make them appear to be easier than they are like myself ( I have been a vehicle technician for nearly 35yr and an mot tester for 20 yrs but things still go wrong sometimes) so hats off to you for coming on here and holding your hands up rather than just getting it sorted and posting up that job done all went well .

Stephen.

 

[mrscalex]

Doesn't matter how many years repairing cars you have behind you easy to have a moment and do something wrong the experience bit comes in when you realise and what you then do to remedy the issue good to see that you know what has happened therefore have a fix .
I also like the fact that you have posted what has happened on here shows others that unless you take proper care these sorts of jobs can run into issues as I think sometimes these jobs when posted ( by competent people) can make them appear to be easier than they are like myself ( I have been a vehicle technician for nearly 35yr and an mot tester for 20 yrs but things still go wrong sometimes) so hats off to you for coming on here and holding your hands up rather than just getting it sorted and posting up that job done all went well .

Stephen.

Thanks Steve. Only really on here to learn and share back with others. So happy to put my hand-up if I've done something daft so others can benefit. You are right about people making some jobs look easy. And in fairness this is an easy enough job if you are very careful. I usually am but I let my guard down this time.

Anyhow. Think I have found a tool to get the solenoid off so back out in a bit to see if we can get the job completed.

 

[mrscalex]

Managed to get the exhaust solenoid out by removing the fan. So both piston's orientation now swapped.

Fired-up first time and runs sweet as a nut. Won't be able to test drive until later when I need to make an essential journey. But the actual position of the CAM timing is noticeably closer to and noticeably quicker to reach the DMEs target in INPA. So fingers crossed job's a good'un.

 

[mrscalex]

I'll note a few lessons learned once I'm happy after the test drive.

 

[Stevo7682]

Glad to hear you've sorted it .

I'm sure when you get round to the test drive it will run fine .

Stephen.

 

[t-tony]

I agree with @Stevo7682 Rob, I suspect that not everyone would post up having dropped a b******* for fear of looking silly, but anyone can make mistake and usually it is a simple thing sometimes easy to resolve and sometimes not. Fair play to you mate.

Tony.

 

[mrscalex]

Well I managed to give it a quick run when I picked my lad up from his mother's. All seems okay. As promised some lessons learned. I know loads of people have done this job before and there are plenty of write-ups so not a how to but you don't always get some of the little detail:

• X8R kit very good. They do different flavours but I went for the second largest kit as it has all the gaskets etc you're going to need including the valve cover. It was £99 - https://x8r.co.uk/products/bmw/bmw-...als-repair-set-kit-m52tu-m54-m56-with-gaskets. There is a £139 kit that also has the rattle rings but I took a chance I wouldn't need those as the expense has to stop somewhere. It turned out fine without them
• You will need the valve cover gasket unless it's been replaced recently. Mine was rock hard. So you may get a benefit from that alone if the old one was causing any leaks
• I had to remove the fan and fan shroud to get the VANOS out. No need to remove the radiator. Though it is a b*gger getting the fan back on with the radiator there
• Better to remove the VANOS unit with the solenoids attached. And return it with them attached - tightened up. You'll struggle to get a spanner in to tighten them up afterwards. Ideally they need new o-rings (not in the X8R kit). Mine got delayed arriving so I took a flyer on reusing the old ones and they were fine
• Doing the VANOS seals themselves is easy. The core is a very simple unit. About the same difficulty level as brake caliper seals but a little more work to get the seals sized/seated correctly. The harder (longer) part is dismantling everything that needs to come off to do the job and putting it back afterwards of course
• There will be plenty of oil expelled. Let's say a teacup full. Doesn't sound a lot but it will go everywhere. It will come out when you take the piston caps off and when you remove the VANOS itself. You need rags underneath on hoses etc and a drip tray on the ground
• The VANOS unit itself will have plenty of oil on it. Clean it off (eg with carb cleaner) before you dismantle it. Then clean the oilways and piston bores once dismantled. Best worked on in a clean environment like the kitchen table - no mrs scalex to tell me off in my house. But it would be a no no in her house!
• The exhaust piston is spring loaded. But the spring will fit physically on either side. So remember to put it back on the correct piston - the one with the cover with 4 bolts. The inlet has 5 bolts
• Put the pistons back in the bores they came out of. They are the same size but just good practice I guess
• The solenoid pistons go back in with the spring first! The bit I got wrong! You will get errors 103/104/105/106 if you get that wrong
• Watch this video if the VANOS won't sit straight back on and encounters resistance. I don't know what the parts are called on the end of the camshafts so better to watch -
  View: https://www.youtube.com/watch?v=cjHv9Aj5nwc
  
• The piston securing bolts (to the camshafts) are left-hand thread. The oil-seal caps that go on the end are a b*gger to get back as they are so tight. I blue tacked them to a 1/4 socket (11mm I think) and tapped them in gently
• Put the engine lifting eye back on before the oil supply pipe. If you don't the oil pipe will have to come back off and you'll need more crush washers
• You'll need a torque wrench that goes down to 8Nm. I have a nice little 1/4" one from Machine Mart
• I think the most tricky part is getting the valve cover gasket back properly. The spark plug gaskets like to flop out as you place the cover so put a couple of dabs of instant gasket on each ring to hold it there. Tighten each securing bolt a little at a time in a diagonal pattern starting from the inner bolts. Unlike a cylinder head you won't find a sequence chart. The more important thing is not going round in a radial fashion and doing some sort of diagonal pattern
• I had a donor/swap out unit prepared to speed the job up and give me a fall back if it all went wrong. Expect to pay about £60+ on ebay if you want to do that. The 2.2 and 3.0 are the same unit. In fact my replacement came from a 2.2. You can always sell yours on afterwards
• I spun the engine around without the coils connected to circulate the oil until the light went out. Then 3x 5-10 second bursts for good measure
• I reset the adaptations afterwards but I'm not sure that's strictly necessary as the DME will do it by itself in due course
• 200-250 miles of breaking in required before going mad.

 

[handsomejackuk]

nice write up Rob, thanks for sharing i been looking at a few videos tonight on my single vanos 2.8 m52 i suspect its still on original seals, once my 1.9 is back on road only a rocker gasket to sort, i am going to tear into the 2.8's vanos, i was going to sell the 2.8 but as we have this virus thing i may as well keep hold of it for now, and do a few more jobs on it... m.o.t. is up shotrtly although it has the extension... i gradually coming around to keeping both the z3's

 

[Oddly Godly]

I wouldn't even attempt to do a vanos. The main thing is that you realised what you had done I'm sure others will benefit from your error. We all make them