Dont use a Dorman brand DISA

[jgold47]

when I bought my X at 94K miles it had a bad DISA. The vacuum or something was shot and the flap just freewheeled.

As a firm believer in having stuff working correctly as cheaply as possible, I sourced a Dorman DISA 1) because I could have it quickly from Amazon, 2) because my experience with complex parts like this is that they wind up sourcing the part from the OES anyways (I've gotten duralast parts with INPA/Behr/stampings) and 3) because if its inferior, I don't plan on keeping the car forever, and I drive very few miles (10K in 2 years...WTF ) I'd probably outlast it.

About a month or two ago, I noticed this high pitched whine which I traced back to the DISA, as if it was slightly loose in the hole, and air was sucking in. I wiggled it, and all was good.

Fast forward - I wanted to pull off the DISA and clean and reseat the opening to make sure I had a good seal and not have to worry about it again.

Here is what I found:



The one on the right is what I removed. Its probably got 5000 miles on it.

the one on the left is the new Vaico one I got from ECS. As you can see, the entire surrounding gasket is pretty much gone. There was a lot of what looked and felt like dried rubber cement all over the intake runner and frame which I'm guessing was the gasket material melting and sticking to the runners.

This whole thing boggles my mind that it failed so quickly.

You cant really see in the picture but the 'box' on the (bottom part of the photo) is slightly caved in vs. the new VAICO one. that may be completely normal, but strange none the less.

The VAICO DISA was a tight fit (in a good way), and I had to use the screws to make sure it was fully seated vs. the Dorman which I pushed flush and held with the screws.

So moral of the story, I got a bad Dorman DISA. I suggest you not consider that option, and get either the OEM one, or the VAICO one, which I suspect IS the OES since no one else makes the part.

And PS -

There is absolutely 0 way for the DISA flap pin to work itself out and into the engine. Its not physically possible as not only does it sit flush again the back of the intake runner, but there is an indentation specifically to accept the part of the housing with the pin in it.

Unless the entire flap frame broke, the whole thing torqued forward, and the pin fell out that way. NOT happening in a low stress environment like the intake runner.

PPS -Running out the car last night on a 15-20 mile drive through the country I was getting 21 MPG. I was averaging about 15-16 normally (mostly stop and go) but had dropped to about 12 after finding this issue last Saturday and waiting for the new part to arrive. Car also sounded like a can of marbles, so it must have been running a bad A/F (which is probably why I was getting O2 codes.)

[Ricky Bobby]

I rebuilt my OE DISA valve with the G.A.S. kit which includes a bulletproof flap/pin assembly and a new O-ring for $80 last year, it carries a lifetime warranty.

I have very rarely seen an Original DISA unit from BMW that has failed to the point it would not be fixed and better off with the G.A.S. rebuild kit.

German Auto Solutions M54 DISA Repair Kit

[lo_jack]

I had a thought after reading a lot of DISA threads.

Some people do not want to do the G.A.S. rebuild on an old unit because other things (like the vacuum pot) can fail...rendering your $85 ineffective. Also, presumably, people would rather not spend the cash on a brand new OEM DISA or the G.A.S. gold if they can avoid it.

But what about taking a cheapy dorman and putting the G.A.S. kit (and awesome gasket) on it from the start? That would come in around 220...still saving money and having better reliability than any OEM unit, I would expect.

The failures of the dorman unit seem to be completely offset with the G.A.S. kit. But you get new vacuum and all that as well.

Is there something else about the Dorman ($120 that I can find) that makes it fail/bad?

[Ricky Bobby]

Originally Posted by lo_jack

I had a thought after reading a lot of DISA threads.

Some people do not want to do the G.A.S. rebuild on an old unit because other things (like the vacuum pot) can fail...rendering your $85 ineffective. Also, presumably, people would rather not spend the cash on a brand new OEM DISA or the G.A.S. gold if they can avoid it.

But what about taking a cheapy dorman and putting the G.A.S. kit (and awesome gasket) on it from the start? That would come in around 220...still saving money and having better reliability than any OEM unit, I would expect.

The failures of the dorman unit seem to be completely offset with the G.A.S. kit. But you get new vacuum and all that as well.

Is there something else about the Dorman ($120 that I can find) that makes it fail/bad?

Gary credits your $85 towards a new DISA with the kit installed if your OEM one fails. I see no fault in your theory though, a Dorman DISA with the GAS kit installed should be great.