DISA Unit

[zedonist]

It works via vacuum, so at a certain pressure just flips open, or closed depending on how you view it.

 

[t-tony]

Why, then an electrical connection? Is it a vacuum switch for a small motor?

 

[MAURICE THE MARTIAN]

I thought it opened at certain revs to increase airflow..
M

 

[zedonist]

I don't know Tony, I am talking from an M44 perspective, but even if electronic it would be open or closed, because all it is doing is changing flow routing from short to long, which affects the torque delivery curve between low and high revs. I can't see the benefit in it being only half open or closed etc, which is why I don't see a bearing noise being an issue, but a loose flap pin would cause a rattle.

 

[zedonist]

I thought it opened at certain revs to increase airflow..
M

Yes Mozza, that's what it does, and gives a power boost as it affects the torque delivery, similar to exhaust power boost on motor bikes and a EGR valves on diesels

 

[t-tony]

Thanks Guys, I will have a look because I'm curios now.

 

[micklaw]

I found if I put my finger on the diaphram housing I could feel the rattle. And if you press it you can hear the pitch change.I think m43/44 are the same type of unit £215 from sytner leicester.6cylinder is a different unit alltogerher.
Hope this helps

 

[MAURICE THE MARTIAN]

TBH.When i changed mine there was minimal play but for £50.i got the kit as in Billz link .prevention is better than a damaged engine.
And as said previously my fuel consumption has improved .
M

 

[t-tony]

Got to be worth it for that alone I think Moz .I took mine off today after work and, I assume in the at rest position, it is "open" as in Woody's photos. The thing I don't understand is that if it is in fact open, with no electrical feed or vacuum depression in the manifold why does it appear to "close" when it operates ? Also I don't see where it gets it's vacuum from, if there was a pipe connection, you could suck on the connection and see if the vac capsule is a) working and b) holding vacuum the same as you can on an old school distributor.
My valve appears to be in good condition with no loose parts or rattles so until I find out how these operate and wether it is in fact operating as it should I won't be changing it.
Further research underway.

 

[MAURICE THE MARTIAN]

From memory I think it should be closed with a strong spring action to snap it back, and I mean snap back ,
M

 

[zedonist]

The vacuum unit appears to be on the side of the unit?

 

[micklaw]

My type of unit which is different to the one in the picture has a small hole in it which I could suck on to see if the flap opened.
Mine worked fine an and as tony said there were no loose bits but it still made the rattling noise.just like the engine to sound as quiet as poss

 

[bruce&kim]

bit confused on this checked the ebay guy and it doesn't seem to fit the 1999 2.8 anyone found another supplier ?

 

[oldcarman]

I'm surprised that considering this part/ device has been in place since at least 96 that there seems to be so little understanding of it's purpose and construction. Obviously it couldn't have been a major concern until lately and in a low milage car to boot. Does kinda make you wonder if it will happen to you. I've seen situations like this over the years where perfectly good parts were replaced with new only to have a problem show up with the new part. It's a crap shoot at best which way to go! Good luck everyone. JIM

 

[zedonist]

I'm the same mind as you Jim, wait till it breaks then change, alas, though there is a chance that broken debris can get in the engine in extreme cases.

 

[oldcarman]

My father in law was a preventive maintainence junkie and one summer I replaced three starters and his carb. He was getting 28 mpg but only 13 with the new carb. Same with spark plugs, etc. I bought three of his vehicles and drove them all without incident, just reg oil changes, etc.

 

[Applied Thought]

It seems I have a possible disa issue on my 1999 2.0

Does anyone have a recommendation for either a complete unit supplier or repair kit.

Thanks

 

[MAURICE THE MARTIAN]

It seems I have a possible disa issue on my 1999 2.0

Does anyone have a recommendation for either a complete unit supplier or repair kit.

Thanks

Try i6 Automotive, sheffield, they do a repair kit, got mine from them 3.0 Z4, cost about £50, an better than original now,
M

 

[Applied Thought]

Try i6 Automotive, sheffield, they do a repair kit, got mine from them 3.0 Z4, cost about £50, an better than original now,
M

Great, thank you

 

[Applied Thought]

Try i6 Automotive, sheffield, they do a repair kit, got mine from them 3.0 Z4, cost about £50, an better than original now,
M

Tried the company but they don't have any in stock. Anyone got any other thought?

Thanks