YRV Problems, noise on over run lack of boost

Submitted by skylab on

Forum: 

Hi all I am a new YRV turbo owner ( I have two of them) one is running perfect and is a standard car 2003, the other is a 2004 car and had been extensivly modified, I am gradually getting it back to standard however I have some problems on the car and was wondering if any one else have come across them, the car has got a large bore twin exhaust system with a centre silencer at the back with the two pipes comming off to the original locations, the cat has been removed and a bypass pipe added, the air intake has been modified an has a huge blitz filter and lots of alloy piping going to it from the turbo intake the engine runs fine but lacks power seems to be just gasping to go but no boost, I have measured the turbo boost and it was around 0.5 bar max, also there is a noise on over run when you take you foot off there is noise that sound like somthing rotating and slowing down, puting the car in N make no difference, but a slight touch on the acelerator (not even enough to make the car go any faster and it disappers take foot off and its back (turbo???) also there is some blue smoke when I have the bonnet open after reving the car slightly seems to be comming from under engine ( is there a breather there??) or smoke from knakered turbo seals ?? I am lost can any one help ???

Thanks Skylab

Sounds like this car was

Submitted by Jpor on

Sounds like this car was designed for Santa Pod Wink It could be a few things;

1).. The Turbo is knackerd

2).. Possible issues with the wastegate

3).. Possible modified dump valve?

4).. You have a leak in one of the pipes causing the lack of boost.

The blue smoke would indicate a faulty turbo, what's the oil dip stick reading? Sounds like you have bought a lemon Sad Out of a matter of interested any pics of the re-worked engine?
Did the car have any extra bits to control all of this? Electronic boost controller, piggy back ECU system etc..?

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'12' Plate Mazda MX-5 2.0 litre NC 3.5 Venture Roadster 160BHP
'15' Plate SEAT LEON 184 FR TDI. 240BHP/500nm Torque.
Past: '53' Plate Yellow YRV Turbo Approx. 150BHP

pigeoning / turbo fluttering

Submitted by Yellow YRV Turbo on

Well, can't answer all your issues, but I think you are referring to the pigeoning sound that you describe as something rotating and slowing down when you remove foot from accelerator.

Is it something like this: http://www.youtube.com/watch?v=8JdyHEs9PnU
If it is, thats quite normal (for a turbo car with an induction/cone filter kit) and for most guys it's desirable and thats 1 of the reasons they fit the induction. Putting the standard box should stop that - have you tried swapping on the box from your standard YRV Turbo?

The pigeoning flutter sound is just the boosted air coming back out through the turbo (in the opposite direction) because taking your foot off the accelerator shuts off the open throttle body quite suddenly and that air pressure/flow has to be released via the easiest route. That is why when you even open the throttle a little, the air gets sucked through and has no need to revert back through the turbo impeller.
I am assuming there is no dumpvalve on the setup?

With all the alloy piping you mentioned, it could be that the setup is too much for the turbo, and the boost pressure is not achieved uniformly

Some photos would really help us here. I am still interested in the induction you have, I think you mentioned sending some photos?

The blue smoke could be oil, but could also be a very wonky air/fuel mix (doing all the mods without remapping/chipping could cause this). Is the smoke blowing out or just wisping around? Could be a small leak onto the exhaust manifold. Is there any smoke from the exhaust at startup, when driving normally, and when driving hard?

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Just call me G... Wink
2004 Yellow YRV Turbo