Holed Dump Valve Responsible for Boost leak?

[SR71]

I hazard a guess this would be a "boost leak"?

If I blow down the side of the valve that exits into the MAF -> Turbo hose, air p***es out of the hole in addition to the rope vac line that leaves the valve.

I can't quite conceive of how it has happened. It seems hard to imagine that abrasion has been responsible for this damage to the housing but I certainly haven't ever done any work to the car down in this area and the car never manifest the symptoms of a boost leak a year ago.

In the space of a year?

Possible?

Thanks for the comments.

[APNess]

I hazard a guess this would be a "boost leak"?

If I blow down the side of the valve that exits into the MAF -> Turbo hose, air p***es out of the hole in addition to the rope vac line that leaves the valve.

I can't quite conceive of how it has happened. It seems hard to imagine that abrasion has been responsible for this damage to the housing but I certainly haven't ever done any work to the car down in this area and the car never manifest the symptoms of a boost leak a year ago.

In the space of a year?

Possible?

Thanks for the comments.

Not only possible, but probable. My guess is that you never saw more than 0.7 bar on your boost gauge. Put the dump valve on from an S3 instead. Cheaper and easier to get hold of, and no difference in performance AFAIK. You should start seeing 1.1 bar on overboost again (if it's an aby)

I also gotta ask... where did you find my old dump valve, and why'd you put it on when it had a hole in? (i.e. I've been there, done that, got the T shirt, and the boost leak. And no fault codes either.)

Well done on finding the leak!

PJ

[SR71]

Not only possible, but probable. My guess is that you never saw more than 0.7 bar on your boost gauge. Put the dump valve on from an S3 instead. Cheaper and easier to get hold of, and no difference in performance AFAIK. You should start seeing 1.1 bar on overboost again (if it's an aby)

I also gotta ask... where did you find my old dump valve, and why'd you put it on when it had a hole in? (i.e. I've been there, done that, got the T shirt, and the boost leak. And no fault codes either.)

Well done on finding the leak!

PJ

Cheers for confirmation PJ.
No overboost is exactly the problem - particularly evident in 5th and 6th!
VAG Parts have a new one on its way to me for half the price of the local stealer!

Having a nosey around now to check all the hoses whilst its apart though!

[Jamo]

Here's something to debate this afternoon (I'm trying not to work, I.T engineers work on a friday afternoon after going to pub, i dont think so!)

IS the S3 valve false economy? (playing devils advocat here )

Its cost what 20-30 pounds but need replacing every what every 12 months (somebody who has one correct me here) on high boost cars.

I have a AMD Viper valve (dont know new price had it years), that needs a rebuild once evey 40K miles for the price of £5.

Is this not better value or is the S3 valve the simple solution?

Answers in pixels below please.

[Jamo]

One final thing, is the valve the right way round? or is the just angle of the picture?

[S2central.net]

@Jamo - That IS indeed the argument for getting a metal bodied TBV. You pays yer money you takes your choice.

@SR71 - This is a VERY common fault on the S2 - I have a TBV graveyard in my garage currently home to about five dead TBVs that have been disposed of in the past year or so... Not all mine of course ! Sometimes the diaphragm breaks inside them, others there is sufficient abrasion in the factory fitted location to rub a hole in the valves body. Have seen that often.


Paul

[auditude]

One final thing, is the valve the right way round? or is the just angle of the picture?

Lol, isn't the valve sitting on top of where it goes, uninstalled in the pic?

[Jamo]

I've had a few too many pint mates i couldn't tell the difference between a DV and a dummy at present.

[audiman]

S3 one cost me 18 quid. Its been on the car for about 5 months now, running at 1.8bar, still works fine

[ericd]

probably a stupid question, but'll ask anyway, the original d/valve on the car was a 034 145 710 A, the replacement I got a while back was a 034 145 710 B, what's the difference between the A & B if anything, both are Bosch only thing I can see is that one of them has a plastic bump-stop/quide on one port and the other doesn't !!

[BRY]

I hazard a guess this would be a "boost leak"?

If I blow down the side of the valve that exits into the MAF -> Turbo hose, air p***es out of the hole in addition to the rope vac line that leaves the valve.

I can't quite conceive of how it has happened. It seems hard to imagine that abrasion has been responsible for this damage to the housing but I certainly haven't ever done any work to the car down in this area and the car never manifest the symptoms of a boost leak a year ago.

In the space of a year?

Possible?

Thanks for the comments.

Mine was exactly the same!
Got a hyperboost now

[Doug_RS2]

i've seen a few like that - maybe a loose snub mount so when the engine lifts it is catching on something? Just guessing!

The S3 diverters do last longer than stock ones - there have been a couple I know of that have blown so they are not invinsible. I don't know if I would put one years life on it - they certainly last ok on most cars - I had mine on my car running 2 bar for a few months and it was fine - then I have used a forge for nearly 3 years on and off. They need the seals changed and new pistons every so often - but you can usually blag a free kit!