N52 DISA Actuator - Broken?

B

Big_Toe_Knee

Member
 Peterborough
Hi all,

Wondered if anyone can shed some light on whether I need a new DISA actuator on my N52 engine.

The link below shows a video of the position the flap was in when I removed it from the intake and also the play in the flap.

https://www.dropbox.com/s/dmbssgvy0x5chty/Video%2012-10-2013%2014%2001%2057.mov

I suspect this is the cause of a drop in my MPG.

Can anyone confirm that is is buggered and needs replacing?

Cheers

BTK
 
Bing had his out last year even though it was working fine. When his was out it was fully open and had no play. Take what you may from that.
 
Thanks for your reply,

I saw Bings thread, I used it to take mine out and check, great thread.

I'd just like to be sure that a new one is needed before I part with the $$$$$$$
 
Sorry, hadn't seen your other post :oops:

In all honesty - having now seen the video - if mine was doing that I'd be looking to get a new one. Mine was fully open and not movable by hand. If you know a decent mechanic/Indy who knows BMWs it may be worth you showing them the video ?
 
Bing said:
Sorry, hadn't seen your other post :oops:

In all honesty - having now seen the video - if mine was doing that I'd be looking to get a new one. Mine was fully open and not movable by hand. If you know a decent mechanic/Indy who knows BMWs it may be worth you showing them the video ?
Click to expand...

No worries, thanks for your reply.

I think I'll be getting one on order tomorrow. I did know an M technician but lost contact with him. Don't really know any good mechanics.

I use the car for daily commutes, 70mile per day, and was getting 34/35mpg over a week sometimes as much as 37mpg, I'm getting 32mpg at the mo, drove like a granny last week and still only achieved 33mpg so hope this is being caused by the wobbly/not working DISA, May have a bit more grunt too :driving:

Only bought the car with 31k on it last March, then a month later got a new job, on 63k now :thumbsdown:

Apart from 2 rear springs, anti roll bar linkage and vanos solenoids it's not doing bad I guess.

I will keep you posted....
 
You definitely shouldn't be able to do that, when I took mine out (Bings thread :thumbsup: ) it was open at 90* and not movable at all.
 
Afaik you can buy replace parts from Ebay to replace the damaged parts. This has the advantage of replacing the plastic parts with metal because if you buy a new DISA from BMW you get a unit that is still prone to this type of failure. That's my plan when I check mine if it's not right.
 
Erwego said:
Afaik you can buy replace parts from Ebay to replace the damaged parts. This has the advantage of replacing the plastic parts with metal because if you buy a new DISA from BMW you get a unit that is still prone to this type of failure. That's my plan when I check mine if it's not right.
Click to expand...
You are absolutely correct... for M54 engines. That kit cures the dreaded pin-falls-out-into-engine threat, but does nothing about the internal operating mechanism, which is the problem here... for N52s, a different operating concept entirely though in the end does the same thing to "tune" the manifold.
 
Yesterday I picked up my new DISA valve, I'd already made the decision to replace, more money than sense maybe? :cry: but from all you comments I pretty confident it won't be a waste of money.

null_zpsdbeba376.jpg

Old on the left, new on the right, approx £220 direct from BMW. New DISA is in fully closed position but understand that one fitted to the car and then removed the rest position is in the fully open position. I'll probable check this next week, just because I'm nosy :)

null_zps9ac84317.jpg

I've been replacing my rear discs and hand brake shoes this morning but just opposed the new DISA in so will give it a test drive tomorrow. I should image it'll take 20 mine or so to settle down?
 
Big_Toe_Knee said:
I'll brake the old one apart to see what's actually failed and report back
Click to expand...
Good man! I imagine it won't take long for the ECU to adapt to the new state of affairs.
 
bcworkz said:
Erwego said:
Afaik you can buy replace parts from Ebay to replace the damaged parts. This has the advantage of replacing the plastic parts with metal because if you buy a new DISA from BMW you get a unit that is still prone to this type of failure. That's my plan when I check mine if it's not right.
Click to expand...
You are absolutely correct... for M54 engines. That kit cures the dreaded pin-falls-out-into-engine threat, but does nothing about the internal operating mechanism, which is the problem here... for N52s, a different operating concept entirely though in the end does the same thing to "tune" the manifold.
Click to expand...

You learn something new every day. :thumbsup:
 
UPDATE

Drove 180miles today, non motorway, stuck behind trucks but plenty of chances to over take and get up to speed :D with a bit of through town driving in traffic.

The Z averaged 38.6mpg, whereas before the DISA change I was lucky to return 33mpg

Happy as Larry, smoother on idle too :thumbsup: seems to be worth the £220 to replace
 
Good result! :thumbsup:

So you had bad mileage, no other clues, and on a hunch decided to pull the DISA? Brilliant reasoning there!
 
Not really, I saw Bings post and being nosy thought I'd have a look at mine and found it to be in the middle, half open, half closed position.

Thinking back, mpg was down for a few months but was putting that down to driving a little more enthusiasic, roof down etc.

Also seems to run smoother at idle from cold (think I already mentioned that), also maybe my imagination but seems a little quieter at motorway speeds.

Update, today now clocked a couple of miles short of 300 and averaged 37.1mpg and had some fun on the 55mile drive home to my parents tonight. :driving:

If I get chance to tomorrow I will check the new DISA is in its fully open position. Also I'll dig my multi tool out and open up the old one and see exactly what had failed.
 
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