Blow-off valve, boost leak

spacecadet

Member
Messages
378
Recently I was suspecting boost leaks because the boost gauge never reached the yellow zone, only around 12am. Without a boost leak tester I was only able to manually verify parts. First I thought it's the AMAL valve but testing it with 12V it seemed to work properly. I've recently replaced the intake manifold union and cleaned the intake so I expected it to be ok. Finally checked the blow-off valves and found a broken membrane in one.

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This causes a leak from the intake manifold (through union part no. 5) back to the pipe after the air filter. It's neither good for the turbos since the valve never opens.

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Is there a recommended aftermarket valve instead of this weak looking plastic Bosch (0 208 142 102)? Same functionality (no atmosphere dumping), preferably black to blend in. I was checking the Forge ones, FMDV008, pretty pricey but replacing the turbos would be even pricier.
 

chad5k1

New Member
Messages
167
I understand it is a Bosch part and basically the same as on most 1.8t V.A.G. group cars.
But I've never had cause to check properly.
 

Wally

Member
Messages
244
Yes, you can buy the Audi-equivalent. Works fine. When you replace it, better reverse position too. The Philosophy behind this, is that it works smoother/better and prolonges life of the membrane.
 

urquattrogus

Member
Messages
838
I used the APR R1 on my urquattro in place of the Bosch Part.

It used a Nomex diagpraghm, but was pretty expensive.

There are other recirculating valves like Bailey< Forge etc, most of these are of the piston type.

They are all fairly interchangeable providing the pipe size is the same, and fittings are at the same angle.

Just make sure you get a re-circulating one and not a "vent to atmosphere" otherwise you will get the annoying whoosh noise every time you lift off.

Some people also call them diverter valves.
 

urquattrogus

Member
Messages
838
If you are running standard boost pressure, and the OEM ones are not over expensive, maybe stick with standard.
 

spacecadet

Member
Messages
378
Thanks all for the suggestions. So this seems to be a common problem (even in *** group) but there are a lot of options:

- Bosch stock, this also has different version, 102 replaced by 108 replaced by 114, see http://forums.vwvortex.com/showthread.php?3215562-the-mother-of-all-Diverter-Bypass-Valve-posts
- Aftermarket piston style (Generic, whatever from Autoitalia, Forge, etc.)
- Aftermarket diaphragm style (APR R1)

Now just have to decide :)

When you replace it, better reverse position too. The Philosophy behind this, is that it works smoother/better and prolonges life of the membrane.

Do you have it reversed? Did you experience any change or it's just the longevity of the valve?
 

chad5k1

New Member
Messages
167
I'm not sure I'd call it common. I've not experienced it, but have heard a few have - as you can see.
 

spacecadet

Member
Messages
378
Indeed good find.

Though I stayed on the stock route. Bought a 06A 145 710P, latest revision of the 710 series. 710N is said to hold higher pressure but 710P is enough for the standard level. It was on stock at the local auto parts chain for 35 EUR. These are not made by Bosch anymore, they sold the moulds to Kayser.

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