VANOS seals break-in

[the Nefyn cat]

Being as these Vanos things are just an on/off switch I wouldn't have thought that, beyond the normal taking it easy for the first few miles to make sure it all works and nothing falls off, there'd be anything more to come. Certainly didn't notice any improvement over time after I did mine, just a difference to start with, no more flat-spot around 3000ish. Have you tried clearing any adaptations it may have made to itself while things weren't right?

 

[t-tony]

I suspect that there are people who don't know just being over cautious and then after a while they believe it for a fact. Then it gets carrird over and causes people to worry unnecessarily.
They don't even advise you to run in a new car anymore, and haven't for many years, but people still do because they think they should.

Tony.

 

[mrscalex]

Well I’m looking for an informed view and @Delk appears to have that. Thank you.

So I’ll put it out there that the break-in advice offered with these items is a load of cobblers as suspected!

 

[mrscalex]

Being as these Vanos things are just an on/off switch I wouldn't have thought that, beyond the normal taking it easy for the first few miles to make sure it all works and nothing falls off, there'd be anything more to come. Certainly didn't notice any improvement over time after I did mine, just a difference to start with, no more flat-spot around 3000ish. Have you tried clearing any adaptations it may have made to itself while things weren't right?

They are progressively positioned I believe. I’ve seen the angle change by hundredths of a degree over a range in INPA rather than just one position or another.

 

[mrscalex]

I did clear all the adaptations. I’m going to try the plugs and coils next.

 

[Mario]

They move progressively to their end requested positions but across the rev range they are either fully advanced or fully retard as opposed to the M cars where the vanos can be on any position in between depending on conditions I might be wrong

It's how quickly they move to those target positions that is affected by seals not sealing properly

 

[Mario]

Hello juts been reading and I was mistaken the m54 engine is infinitely variable too on both camshafts my bad. Still as long as you reach target position quickly enough then you are good. There's a test on DIS that checks this automatically for you.

 

[mrscalex]

Well we decided to let rip and can report with the VANOS seals done it was pulling much more strongly above 3,500 revs. Pretty much where I'd expect it to be. Maybe slightly short and definitely not right below 3,500 revs.

We then did the CCV and cleaned/checked all the bits that come off with that so DISA, throttle body and idle control vave. But there was no refurbish necessary with the DISA in the end. Pin firmly attached, excellent strong vacuum and nice flap operation. I also replaced the upper intake hose as the previous item was a pattern part that just didn't sit right. The lower hose was carefully checked and was perfect.

All this further improved things above 3,500 revs but below that it still felt sluggish.

So we've just done the air filter and plugs. The plugs looked original and the electrodes were quite badly worn. But they were a nice light brown colour.

Glad to say the plugs seem to have been responsible for the final missing performance. We just tried it out and it goes like a rocket now. Very pleased with the result from the work we've done.

We also did a smoke test. I succumbed and bought one. @colb will be disgusted with me But we were never going to get over anytime soon in this lockdown and I could no longer resist investing in something. I value these things highly (and @colb 's work) for highlighting hard to find issues. Wonderfully simple to use and confirmed everywhere was good with the exception of the dipstick o-ring and a split vacuum bung at the rear of the cylinder head. Even then the bung was fine until disturbed when it was apparent there were splits. These things are always rotted if they've never been replaced. The dipstick isn't leaking any oil so we'll sort that in due course. And I'll get hold of a bung too.

 

[Mario]

Which smoke test did you buy? I might buy one to trace a pesky small vacuum leak i think I have

 

[mrscalex]

I'll message you on WhatsApp. Then you can get any additional detail you like more easily.

 

[colb]

Self sufficient with the smoke now then, good bit of kit to have given how finiky these engines are about good vacuum, that dipstick seal would have been hard to spot without smoke leading you to it, same for the blanking plugs on the inlet. Once the lockdown is lifted @handsomejackuk will be comming to the shed for a smoke test since he replaced the cam cover gasket over the lockdown. I should really do the same on the Z4 as thats had a cam cover gasket change as well, may wait till I refresh the CCV on that.

 

[mrscalex]

It was an extravagance to buy that's for sure. But I'd saved a few pennies through the lockdown and didn't want to wait any longer to get the massive results these things can give.

I could also help justify it from having multiple cars on the go.

You are right about the dipstick leak. No way would I have spotted that. The bung leak, well they would have been routinely replaced at some point anyway as they always go.

Given that I'd had so many parts off that engine I wanted to be sure I'd got everything back sealed correctly. The cam cover gasket alone is a little bit of a devil to get right and I was particularly pleased that checked out okay.

 

[colb]

Having done a couple of cam cover gaskets now, one onDaves 2.2 Z3 and my 2.5 Z4 it seems to me people can go wrong when replacing if they dont put in new round bolt seals that sit under the cover retaining bolts. They go hard as well as the main gasket and plug well gaskets. BMW recommend changing the bolt seals and I would agree. Those bolts will only tighten up to a specific point and compress the cover no more. If those round seals have gone hard they don't compress when tightened so you can end up with a bad seal on the main gasket. Having dealt with @Davester2.2sport cam cover that had cracks develop around No4 plug well its always worth giving the inside a good clean and close inspection for cracks as well as straightness in case its warped. We wouldn't have found those cracks without using smoke much like you and your dipstick seal. I did look at those retail available smoke machines but decided to have a go at making one using bits I had in the garage, I did outlay on a new paint can and some resistance wire, that cost me under a tenner, rest of the bits I had. Amazed how good it worked in the end. You won't regret spending out on yours, its such a useful bit of kit to have.

 

[mrscalex]

Yes my bolt seals got changed along with the plug well seals. Hadn't even stopped to think some folk might not bother with all the bits. I guess you're right and then they wonder why it leaks. I did follow some sort of criss-cross pattern as well and I torqued the bolts - I think only a couple bottomed-out.

To be honest I rank a smoke machine up there with a code reader. Sounds a bit extreme but that's how I see it. The code reader is essential to keep your car going at all. The smoke machine to keep it going at the top end of it's ability. And we all want our cars working at the top end of their ability don't we?

Despite buying off the shelf, I still offer you big congrats on building your own. I think it was a project too far for me to have a go at and I just wanted to crack on. I'm using the lockdown to get all sorts of other jobs done round the house and didn't want to stop to build one which may or may not have been successful for me.

Hope to still catch up with you guys at some stage anyway. Maybe we can compare smoke machines You'll win for initiative alone

 

[Pingu]

I can't talk for non-M VANOS set-up, but the speed of cam reaction is more to do with the strength/weakness of the diaphragm spring. If you have slow reaction times, I would suspect the diaphragm spring. It is VERY important to the correct running of the engine that the torque of the hub that sandwiches the spring is correct. Too tight and the reaction speed will be too slow, too loose and the gears will chatter.

If your engine sounds very quiet and the reaction time is slow, I'd suspect the torque is too tight, or the spring is too strong. It may be possible that a new spring (if one has just been fitted) may need to settle down. If this is the case, I'd have thought that a quick blast would be enough to sort that.

A failed solenoid seal would leak oil from the VANOS onto the void between the solenoid securing plate and the solenoid until it is either full or it leaks. It is very unlikely the gasket and sealant would prevent a leak as the oil pressure in the VANOS is VERY high. In other words, if a solenoid seal is leaking, there would be a visible oil leak.

 

[mrscalex]

I had testo on my 3.0 before and after. The reaction time and final position were both fixed by changing the seals.