DISA Valve

R

Rizel23

Member
Getting a constant ireggular from the engine and trouble shooting.

1. Slightly strong smell of petrol
2. No obvious performance drop


Started with DISA valve.

1. Working correctly
2. Little movement in pin

Upon taking it off some blue type sealant was surrounding it, new go Z4’s but take it not common practice.

Do seals look ok?

E85 3.0 2004

Thanks

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Any further guidance appreciated.

Tempted to remove sealant, resel with gasket sealant and if noise goes remove and purchase new what is required, thoughts? Thanks
 
Someone been in there before you then, shouldn't need any sealant on there the red seal should be enough to provide the seal, clean it off both parts and have a close look at how it fits in there before resorting to using any sealant. Better still clean it off, refit it and then get it smoke tested to see if there are any air leaks in the entire system. Pumping smoke after the Maf and throttle pedal held down will allow smoke to find its way through the engine and show up where there are leaks, usual leaks are in the rubber hoses when they split or get holes in them. It will escape from the Disa seal if its leaking, my guess is the hiss you hear is elsewhere.
 
The orange o-ring on the DISA that seals into the orifice on the manifold should be round in section not flat like yours. It has become flattened with age. You can buy a new o-ring on Ebay, you just need to scrape out all the old orange one first. Alternatively clean all the blue sealant off and reseal with some decent silicone RTV gasket maker like I did :thumbsup:
PS the hiss is likely to be the short convoluted rubber tube on the main rubber inlet boot connected to the throttle body. They are famous for perishing and cracking.
 
Thanks both.

I will replace, ive just sealed it to test if it’s causing the hissing. Letting it cure now.

It appears that rubber tube inlet has been changed as looks pretty new so doesn’t look like the issue.

I’ve read it could possible be;

1. Secondary DISA valve?
2. Leaking CVV?

Causing hissing
 
https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=bmw+disa+o+ring&_sacat=0
 
Just been looking at photos of the DISA seal and appears cracked in two spots;

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Would this cause hissing sound? The sound does appear from this area? Thanks
 
Hi there....hissing sounds are usually caused by cracks or leaks on the intake hose past the maf. They get brittle with age, sometimes mere taking it apart causes it to crack. That's what i had on mine...hissing sound on low rpms. :D
 
carlsson said:
Hi there....hissing sounds are usually caused by cracks or leaks on the intake hose past the maf. They get brittle with age, sometimes mere taking it apart causes it to crack. That's what i had on mine...hissing sound on low rpms. :D
Click to expand...

Many thanks I have carefully check all hoses, the sound appears within the manifold area where the DISA is located.
 
It sure sounds like an air leak....if no hoses are cracked maybe it’s the seal in the DISA valve. I hope it’s not an intake manifold leak.... but i think you’ll have drivability problems if the intake manifold is leaking.
 
Well I’m still battling with this.

Bought a new DISA, no difference so going back as original working fine.

All hoses in DISA side checked.

Sprayed everything with WD 40 and no change in engine pitch.

No misfire codes and drives ok, just not ‘right’ and running lean with o2 codes being registered I presume on emissions.

Going to get booked in for smoke test.

Thoughts now;

1. CVV (although there is small suction on oil cap when removed and ballon inflates on oil dip so appears norma)
2. Manifold gasket failure

Can’t think it would be a cracked manifold as it still drives strong.

Thanks
 
Well update.

Had the CCV and manifold gasket changed, pipes had not cracked but some hoses were loose and could be turned at the head :o

Oil dipstick, throttle body and air distribution seals also changed for good measure.

Engine now running great and no abnormal sounds 👍
 
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