Dump valve no worky

[junior munky]

Hello,

It's been a while - probably 8 years or so since I posted on here. I had a black Leon Cupra R from new, but sold that around 7 years ago - I wonder if anyone on here has it? KL52 EJ?

I have a problem with my current runaround - a 2001 Octavia. Yes, yes I know I'm posting in the wrong place, but I thought as it's the same engine, one of you helpful people might point me in the right direction?

I'm pretty sure my dump valve isn't working - It's not leaking on boost, but I don't think its opening when the throttle closes as I get a lovely chatter sound from the turbo. Is it likely to be gummed up, or is the problem more likely with whatever opens the DV? Annoyingly for years I had the OEM DV which I swapped out on the LCR for a Forge, but I think it got binned only a couple of years ago...

I also noticed there is a split in the lower breather hose, but I'm guessing it's not likely to be related? From the history that came with the car I can see the DV has already been replaced once.

Cheers

Olly.
.

 

[junior munky]

Should have said, this is a 1.8 20vT engine.

 

[cuprastoffs]

If you have a chatter its usually a non opening d/v.

 

[andycupra]

check DV but also sort out the lower breather pipe, it may be this does have an effect, even if indirectly, such as build up in pipes/DV.

 

[junior munky]

If you have a chatter its usually a non opening d/v.

Yep. I get that. I'm asking if there is a common mode of failure. Do they get gunked up or is it the actuator that operates the DV? No fault codes on OBD. I have a breather pipe set on order so will take it from there.

Thanks guys.

Olly.
.

 

[wakko]

The OEM DV's are a known to be a bit shite and is the reason people replace them with Forge DV's They can get gunked up and the heat they handle doesn't help. The DV is opened with vacuum from the intake manifold, so check that pipe for starters but it does sound like you need a new DV, preferably a Forge.

 

[traumapat]

The OEM DV's are a known to be a bit shite and is the reason people replace them with Forge DV's They can get gunked up and the heat they handle doesn't help. The DV is opened with vacuum from the intake manifold, so check that pipe for starters but it does sound like you need a new DV, preferably a Forge.

You might want to update your info.
http://www.youtube.com/watch?v=UED0ICAMrYI

Forge are now giving updated pistons out to fix leaks.
OEM valves are now fine (probably always were).

 

[RICKY3]

You might want to update your info.
http://www.youtube.com/watch?v=UED0ICAMrYI

Forge are now giving updated pistons out to fix leaks.
OEM valves are now fine (probably always were).

+1an oem valves are only £ 30 ish


Sent from my iPhone

 

[cuprastoffs]

The OEM DV's are a known to be a bit shite and is the reason people replace them with Forge DV's They can get gunked up and the heat they handle doesn't help. The DV is opened with vacuum from the intake manifold, so check that pipe for starters but it does sound like you need a new DV, preferably a Forge.

That's shite!
I fitted a split-r, was just a boost leak that sounded ok, then a 007 (without revised piston) and it leaks too. Back to standard Bosch and its great pulls really smooth and no leaks.
It's usually the rubber diaphragm that splits causing failure to open.

 

[AeroMad]

I'm still learning about the 1.8T engine so go easy on me, but would a failed N249 contribute to this fault as it's connected to the DV.

 

[cuprastoffs]

Possibly, have never heard of one fail.
Worth doing the bypass to rule it out though.

 

[leoncupra2012]

Ive got the standard bosch valve on a stage 2 , 240bhp AUQ cupra? is that right? it was on it when i bought it, thinking about changing it as i dont really like that turbo flutter sound.

 

[andycupra]

I'm still learning about the 1.8T engine so go easy on me, but would a failed N249 contribute to this fault as it's connected to the DV.

interesting question... id say unlikely, i can say for sure though id have to look into it more.
however, many people remove the N249 system and they run ok. My understanding is its there to assist in the DV operation, rather than it being required.
As said above you could bypass it to eliminate.

 

[cuprastoffs]

Ive got the standard bosch valve on a stage 2 , 240bhp AUQ cupra? is that right? it was on it when i bought it, thinking about changing it as i dont really like that turbo flutter sound.

Sounds like your d/v is not operational, get a new bosch, from experience I wouldn't recommend a forge.

 

[junior munky]

I bought this one: http://www.ebay.co.uk/itm/380446105058

Looks like a clone of the Forge. It arrived this morning and I fitted it a few hours ago. That was definitely the problem. No more swooshy sound on throttle closure and no more me having to ease off the throttle gently when possible to preserve the turbo bearings

Thanks for your help guys.

I have a breather hose kit too which I'll fit at the weekend if the weather isn't too dismal.

Cheers

Olly.
.

Edit - The old D/V failure was probably diaphragm as when I suck through the actuator pipe I can't build up any vacuum - air leaking in from the "side" pipe.

 

[leoncupra2012]

I was looking at those ones but wasnt sure. Sure someone had one of those on here before and it cocked up shortly after somehow.

 

[junior munky]

Oh dear Well I'll keep an eye. Only 150bhp so perhaps I'll get away with it. Comes with 3 springs, I have middle strength fitted.