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Discussion Starter #1
Ok, thanks to all of you good people who posted videos/how-tos/etc I was able to easily swap my DISA Valve. Mine was TOAST so it's a good thing I did it.

Anyway, idles like a champ now. Only problem, when I step on the accelerator, it sounds like it's sucking air for half a second then it revs just fine. Everything seemed sealed fairly well so I'm not sure what it might be. Any suggestions?
 

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Discussion Starter #2
Oh, I didn't drive it because I was worried about that.
 

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If the sound is new since doing disa replacement, I guess I'd wonder first if you replaced the o-ring behind it.

If you did, then perhaps you removed other stuff to get to it and didn't get it back properly.

On the upper intake boot, that vac hose sticking in it has a grommet inserted into the boot...and that seems to dry out and would be another air leak site.

Old ccv hoses seem very brittle too and maybe you hit one while doing disa (sorry)...but, you know, that lower intake boot is famous for cracking...so take a hose about 5' long and stick it near the lower intake boot, or around engine to isolate location of your offending sound better.

Maybe if you removed air box, you didn't get everything tight together...as in maybe lid to air filter box...or one of other hoses?

HTH

Doug
 

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Discussion Starter #7
If the sound is new since doing disa replacement, I guess I'd wonder first if you replaced the o-ring behind it.
It is a new sound for sure. I didn't notice any o-ring when I removed the old one--seems like it's got it built-in. I just pulled off the old one and replaced it with the new one. Didn't notice anything falling off when I removed the old one, etc.

If you did, then perhaps you removed other stuff to get to it and didn't get it back properly.
Thought of this. I double checked before I buttoned everything up and fired it up. Not much to forget (thankfully).

On the upper intake boot, that vac hose sticking in it has a grommet inserted into the boot...and that seems to dry out and would be another air leak site.

Old ccv hoses seem very brittle too and maybe you hit one while doing disa (sorry)...but, you know, that lower intake boot is famous for cracking...so take a hose about 5' long and stick it near the lower intake boot, or around engine to isolate location of your offending sound better.
Originally checked all of this to be sure but the hoses are like new (not dried out or anything). No cracks/etc. Wonder if I didn't get something on all the way tight... But would this cause the sound to come out of the DISA valve? That's definately where the sucking sound is coming from and there's a definite hesitation.

Maybe if you removed air box, you didn't get everything tight together...as in maybe lid to air filter box...or one of other hoses?

HTH

Doug
I'll check this again but same question as before. Would this make the DISA valve make a sucking sound?

Thanks!
 

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did you order the correct DISA valve? there are 2 different versions used on E46's.

did you get OEM from a dealer or aftermarket
 

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When I changed a friends of mine he had a bad DISA and a ripped lower intake along where the smaller meets the larger. On mine it was just the DISA with no problems after replacement. However I did change my lower hose for the hell of it but found no rips. My friend didn't want to change his hose, however, upon install of the DISA, his was definately ripped which required a trip to the dealer to get one. Sometimes those intake hose look perfect, like my friends but rips form in the folds and they tend to dry out due to the heat.

I believe the differences between the the different part numbers for the DISA has to do with the pivot point on the end. I think the older part had a plastic pin and the newer one has a metal pin, or is that reverse. Can remember because I think of the two I changed one was plastic and one was metal but I seem to rember that the replacements were metal???

Also the gasket is built on to the DISA, both versions I have seen were.
 

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http://www.realoem.com/bmw/showparts.do?model=AM53&mospid=47723&btnr=11_2195&hg=11&fg=40

Well, my disa is from a '99 and it does have an 0-ring and I replaced mine when cleaning disa (which was fine)...

But, I recall someone saying something about one part I'd said had an o-ring or gasket not having one...and it may have been the disa...and recall that he'd said that he just used rtv and that it looked the original had that too...I don't know if that was disa or not...but thought I'd mention it in case it helps.

If the sucking is coming from disa and you didn't notice specifically a gasket or rtv...seems like something should be there.

Okay, checked for your model, OP, and it doesn't show an 0-ring...so the only thing I can think of, again, assuming it is from disa...that maybe the mating surface had residue from old gasket...or that it was rtv and you didn't notice it on either mating surface or on old disa...that, or maybe your new disa has a crack or otherwise is bad...or...did you disconnect battery for a half an hour? I wonder whether the adaptation from old disa is still working and thus you're hearing funny sounds coz of that? All guesses again...obviously!

Doug
 

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Discussion Starter #13
did you order the correct DISA valve? there are 2 different versions used on E46's.

did you get OEM from a dealer or aftermarket
Went to the dealer and got OEM. Last numbers on DISA are 805 which, I think, is the correct number. But good thinking!
 

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Discussion Starter #14
http://www.realoem.com/bmw/showparts.do?model=AM53&mospid=47723&btnr=11_2195&hg=11&fg=40

Well, my disa is from a '99 and it does have an 0-ring and I replaced mine when cleaning disa (which was fine)...

But, I recall someone saying something about one part I'd said had an o-ring or gasket not having one...and it may have been the disa...and recall that he'd said that he just used rtv and that it looked the original had that too...I don't know if that was disa or not...but thought I'd mention it in case it helps.

If the sucking is coming from disa and you didn't notice specifically a gasket or rtv...seems like something should be there.

Okay, checked for your model, OP, and it doesn't show an 0-ring...so the only thing I can think of, again, assuming it is from disa...that maybe the mating surface had residue from old gasket...or that it was rtv and you didn't notice it on either mating surface or on old disa...that, or maybe your new disa has a crack or otherwise is bad...or...did you disconnect battery for a half an hour? I wonder whether the adaptation from old disa is still working and thus you're hearing funny sounds coz of that? All guesses again...obviously!

Doug
Hmm....

I wiped down the port where the DISA goes into the intake before putting the new one on but I did NOT use RTV. Maybe I should?

Hadn't thought about disconnecting the battery to let the ecu reset. Didn't think about that. Wondering if maybe this is the problem. It's pouring here (again) thanks to the tropical storm though. If it stops I'll try disconnecting the battery for a while and see if that helps.

Was also thinking of unplugging the DISA to see if I'm still getting the problem--not sure why I didn't think about it yesterday...duh! Should isolate the problem...
 

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http://forum.e46fanatics.com/showthread.php?t=755501&page=5&highlight=rtv

See #84...poster spit on his disa and it sucked the spit in...so he sealed with rtv...also a 330...so prolly also one without an 0-ring. Maybe there's a tis that mentions using rtv...or maybe the built in gasket, presuming there is one, isn't enough...or maybe the torque you used was off...but don't crack it!

I recall that in this same thread, someone said they'd found remains of old rtv, which iirc, was said to be original...so with any luck...you owe me a black and tan!

Doug
 

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Discussion Starter #16
http://forum.e46fanatics.com/showthread.php?t=755501&page=5&highlight=rtv

See #84...poster spit on his disa and it sucked the spit in...so he sealed with rtv...also a 330...so prolly also one without an 0-ring. Maybe there's a tis that mentions using rtv...or maybe the built in gasket, presuming there is one, isn't enough...or maybe the torque you used was off...but don't crack it!

I recall that in this same thread, someone said they'd found remains of old rtv, which iirc, was said to be original...so with any luck...you owe me a black and tan!

Doug
Sounding like that may be the cause. Have to go pick up some RTV and redo this.

I was careful on the torque. I'm a big guy and don't like to over-tighten things. It's tight but not so bad it will crack something.

I do have a 330. There is a rubber(ish) gasket built-into the DISA but maybe there's some residue I didn't get off and it's messing with the seal.

May owe you that black and tan. Unfortunately, you may have to come to Florida for it. Heading down to Jacksonville on Sunday to give a new job a go. If it works out, I'll be moving the family down before the end of the year. Come on down and hit the beach with me! Black and tans will be flowing...

Thanks. Will let everyone know what I find if it stops raining...
 

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Discussion Starter #18
Jacksonville? Hey, I only helped you coz you said you were from NJ...traitor! LOL

Good luck with new job...hope it works out and that your family enjoys the Fl. summers!

Doug
LOL! Well, it's sort of a forced move, i.e., we can't afford it here any longer! Actually want to move West as in Lake Tahoe. Just no jobs for my wife out there.

And I do have a convertible so I'll get more use out of it in FL... :)
 

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The DISA for a 330 has no O-ring the unit has its own seal built in, the smaller displacement engines do have an O-ring IE 2.5 and 2.8. If you replaced this unit because of a vacuum leak and are now hearing intake sounds it is likely that everything is functioning correctly. The ECS (computer) will take a couple hundred miles before it relearns the new long term fuel trims. The hesitation will go away as the car gets closer to the correct fuel to air ratio.
 

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Discussion Starter #20
The DISA for a 330 has no O-ring the unit has its own seal built in, the smaller displacement engines do have an O-ring IE 2.5 and 2.8. If you replaced this unit because of a vacuum leak and are now hearing intake sounds it is likely that everything is functioning correctly. The ECS (computer) will take a couple hundred miles before it relearns the new long term fuel trims. The hesitation will go away as the car gets closer to the correct fuel to air ratio.
Ah, even better. Hadn't thought about that. As long as the hesitation goes away it idles smooth as silk...
 
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