Post Vanos rebuild - poor bottom end performance

[Oxtobyd]

could hear them inside the car, and I know it was them since when pressing a finger against them, the noise was in time with the movement I felt inside them.

That seems a little odd to me.
I always thought the solenoid was simply on or off, like a mechanical switch. You imply that yours are rattling to and fro?
Does this mean they are not latching properly, or that the signal to them is intermittent?

But as Stuart says, you seem to be getting closer at least.

there was definitely movement inside the solenoid, I could feel it and hear it, so it's interesting they should either be on or off. I'd not considered they should be either on/off and not move repeatedly. I think once swapped for some new items it'll be interesting to see what happens. Any ideas what might cause a rapid on/off movement in the solenoids if I get the same with the new items?

 

[enuff_zed]

could hear them inside the car, and I know it was them since when pressing a finger against them, the noise was in time with the movement I felt inside them.

That seems a little odd to me.
I always thought the solenoid was simply on or off, like a mechanical switch. You imply that yours are rattling to and fro?
Does this mean they are not latching properly, or that the signal to them is intermittent?

But as Stuart says, you seem to be getting closer at least.

there was definitely movement inside the solenoid, I could feel it and hear it, so it's interesting they should either be on or off. I'd not considered they should be either on/off and not move repeatedly. I think once swapped for some new items it'll be interesting to see what happens. Any ideas what might cause a rapid on/off movement in the solenoids if I get the same with the new items?

My understanding is that they operate to open the shuttle valve and allow oil to act on the pistons to move the cams.
I therefore assumed they would be either open or closed, or possibly a linear movement to gradually open the valves more. If they are rattling then that suggests the valves are opening and closing and therefore the pistons will be doing something similar?

I think I would fit just the easily accessed solenoid with anew one first, to see what happens. If it still rattles then it is the signal to it that causes the issue. I am not certain where this comes from to be honest? I guess the cam sensor must report where the cam angle is at, but that would need to be compared to engine rpm, throttle position etc. to adjust the cam correctly. Therefore my uneducated guess would be that the final instruction to the solenoid comes from the DME. But how do you know that is getting the right inputs?

Did you fit new cam position sensors? Though it would be odd for both to fail? Stupid question, but are all the electrical plugs on correctly?

 

[Oxtobyd]

not a stupid question, as i'm all for exploring the obvious, but sadly yes, all plugs on correctly, when I swap solenoids (when they arrive) I'll spray some contact cleaner on them all anyway. yes I did replace the exhaust cam sensor with a new one, but I guess it could be the intake one and maybe worth a swap, I'll leave that for now until I see what happens with new solenoids and pistons.

 

[enuff_zed]

Just had a look at the wiring diagram and it's a straightforward feed from the DME. The fact they are rattling means something is getting through but who knows what part is telling porkies to the DME.

 

[Oxtobyd]

Update.. new Vanos solenoids and pistons arrived, so now fitted (exhaust and intake) still noticed the odd noise from the intake solenoid before taking it for a run (like a rattling noise), but after run nothing there, and also the exhaust p0014 (or might have been p0015) error didn’t return, and finally it pulls away like I’d expect it to. Need a good run in the dry to properly try it out and settle my mind it’s finally sorted.

In conclusion, I think the solenoids were probably already shot, and I’d not really noticed as I’d not driven the car much (as it was a project car for about 18 months fixing odds n sods) then finally got round to driving and figured the Vanos seals needing doing due to poor performance (which they did as the seals where toast), and the final part of the jigsaw was (hopefully) the solenoids (and pistons for good measure). Moral of the story, if ur changing the seals and the car has high miles on it, just change the solenoids and pistons at the same time (the pistons from AUTODOC about £23 each, and solenoids from eBay seller Febi brand about £80 for a pair)

 

[bigwinn]

good work David

 

[Oxtobyd]

good work David

Cheers Stuart, I need to swing by some time and drop off the spares u kindly lent me

 

[bigwinn]

No rush David

 

[enuff_zed]

Good news. As you say, if the vanos wasn't working anyway, it masked the real problem.
Thanks for cataloguing the work you did so clearly. It helps us all down the line.

 

[Oxtobyd]

Just when u think it’s fixed! Had a good run out and certainly better, but still wasn’t 100% convinced, so scanned for codes and guess what…


Grrrr! I think next step, remove exhaust solenoid and piston, get a bottle washer brush that I can bend (due to very tight space to work in) spray with maf cleaner and try and clean inside the vanos recess where the piston goes, thought when I pushed against it last time and after installing new one it seemed to move fine.
Unless anyone else has any ideas

 

[enuff_zed]

The 'stiff' bit was what I had.
I removed the shuttle valve, gave it a rub with very fine emery cloth, smeared it in oil and popped it back in.
Cured it.
I think they build up a layer of varnish from the old oil in the bore and on the valve. Couldn't hurt to clean out the bore too.

 

[Oxtobyd]

The 'stiff' bit was what I had.
I removed the shuttle valve, gave it a rub with very fine emery cloth, smeared it in oil and popped it back in.
Cured it.
I think they build up a layer of varnish from the old oil in the bore and on the valve. Couldn't hurt to clean out the bore too.

Thx, I’d agree other than I’ve replaced both shuttle valves with new items, hence I’m left with trying to clean the enclosure where the valve sits.