Question about chirp noise with car now prodrive CAT/decat is fitted

[westtra]

I have just had a prodrive CAT and de cat fitted. Driving the car for the first time since doing it and in 4th 5th 6th there is a new noise happening.

The best way to describe it is just befoe the boost spike as the turbo spools up there is a chirp(best way to describe it) but not the sound you get with wastegate chatter.

It happens if I burry the throttle or feed in the throttle and get the car on boost quick or slow.

The 2 things I think it could be are possibly DV leaking if the boost spike is bigger now due to more free flowing exhaust. But I cant see how it could be that much bigger. If the DV is leaking what easiest way to check this? Dont have a boost gauge.

The other thing I think it could be is the wastegate closin or opening as the boost settles and now that the new cat is in place I can hear this since there isnt the sound deadening that the standard 2 cats had. But it isnt a flutter as if the wastegate was hunting its just a chirp as if its closing or opening.

Am I worrying about nothing or should I get the old cats replaced? or car looked t? The are no CEL's and it was fitted by subaru mechanics.

The car is completely standard apart fom this and is an 02 bugeye.

Any help or suggestions are appreciated.

Mark

[st3ph3n]

Does the car jerk at all during it?

And what DV do you have fitted?

[cullenmin]

Is it not the standard re-circulation valve that is on your car?

I think youre maybe just worrying about nothing, I'll get a listen on wednesday ne doubt...and a shot[]

Rich

[westtra]

st3ph3n its a standard DV on the car. No jerk bar the the pick up in power from lag to turbo spinning up if I'm below 3k but if above 3k its smooth.

Rich maby get a shot if your lucky someone else did the day though prob am just worrying about nothing but still learning about this engine. Know plenty about the vag 1.820vt if anyone has any questions

[westtra]

Ok just taken the old cats from boot and the turbo outlets are different as the prodrive one has a extra pipe. would this cause the chirp?

Old

New

would this extra pipe be the source of the new sound? and also whats that extra pipe for?

[st3ph3n]

Fixed your pictures for you []

[westtra]

Cheers,

Thought it was me playing about between firefox and IE .

So any suggestions stephen?

[st3ph3n]

I suggest you wait for someone who knows what they're doing to come along []

[jimmyGforce]

This aint gonna be any help but i was gonna post a question which maybe be the same.

80% of the time if i get the boost up to around 1 bar,but with only part throttle i get like a constant chirp/screech form somewhere.hard to describe.can hold it part throttle on boost and the noise will stay.goes away if full throttle though.Noise wasnt there before,even after mods.  i'v swapped DV from recirc to atmos and back and still same.car runs fine still. P1 with full decat,FMIC,CAI kit running 1.45bar

sorry for hijack but maybe be the same []

[westtra]

it is a screech/chirp. have tried to hold the throttle when it happens but cant get noise to stay constant. Get the chirp then nothing. Car runs fine and no warning lights yet. Prob just me worrying about nothing but thought it best to ask incase do some permanent damage.

[jimmyGforce]

i can get mine to do it pretty constant buy just hitting 1bar boost on part throttle.sounds like a screech then. when i do it quick though its like a chirp.think mines is a job for the rolling road so can listen  [:S]

[westtra]

Something I need is a boost guage so I could possibly do that. Think that needs to be next on my shopping list.

[cullenmin]

Something I need is a boost guage so I could possibly do that. Think that needs to be next on my shopping list.

I'm sure SANTA could get you one [][][] How funny am I?

[westtra]

Ha Ha Ha you enjoy bein sober last night?

[fai17]

I think the IHI vf35 are prone to boost flutter which i've heard on my own car and a few other cars.....

Nothing to worry about if it the same noise.

Have you got a CAI?

As this seems to make it louder

[wilky]

Without actually hearing the noise and where it originates from its hard to tell.

Does it come from the drivers side? I imagine it does.

Under partial throttle where your only sitting at say 0.4 or 0.6 bar the screaming is more than likely your boost solinoid. I experienced this, the solinoid was gunked up a bit by an oil overfill and oil being blown around the pipework. This is sorted by finding the boost solinoid which is on your drivers side strut tower, taking all the pipes off (labelling them so you know where they all go back to) and scooshing brake cleaners through the solinoid to clean it then the pipes, bearing in mind both ends of the pipes will need taken off to ensure a clean run through.

If its more or a mooing noise and I mean that, the sound of a feckin cow mooing, then its a buggered standard dump valve. I think I have a buck shee one sitting about here somewhere if its thats.

The chirping is more of a need to hear one but I suspect its your waste gate having the big metal plate removed and a pipe there now its a noise you have never heard but one which shouldnt alarm you. Maybe your arm from the actuator is a bit slack? The actuator is the thing on the turbo that is a cylinder with an arm coming off the back and goes to a wee lever, this is the thing that is pressure controlled and when you get the desired boost pressure, opens the wastegate to ensure the pressure is not exceeded. Give it a wiggle and see. Mind you you would be losing boost but its worth a look anyway.

If you are near stirling PM me and you can come over, but shout at me when Im under your bonnet as Im likely to forget what year your car is, have a senior moment and pull the wrong hose off scalding us both whith coolant as happened once before, lol[]

 

Callum W

[paulc555]

Without actually hearing the noise and where it originates from its hard to tell.

Does it come from the drivers side? I imagine it does.

Under partial throttle where your only sitting at say 0.4 or 0.6 bar the screaming is more than likely your boost solinoid. I experienced this, the solinoid was gunked up a bit by an oil overfill and oil being blown around the pipework. This is sorted by finding the boost solinoid which is on your drivers side strut tower, taking all the pipes off (labelling them so you know where they all go back to) and scooshing brake cleaners through the solinoid to clean it then the pipes, bearing in mind both ends of the pipes will need taken off to ensure a clean run through.

If its more or a mooing noise and I mean that, the sound of a feckin cow mooing, then its a buggered standard dump valve. I think I have a buck shee one sitting about here somewhere if its thats.

The chirping is more of a need to hear one but I suspect its your waste gate having the big metal plate removed and a pipe there now its a noise you have never heard but one which shouldnt alarm you. Maybe your arm from the actuator is a bit slack? The actuator is the thing on the turbo that is a cylinder with an arm coming off the back and goes to a wee lever, this is the thing that is pressure controlled and when you get the desired boost pressure, opens the wastegate to ensure the pressure is not exceeded. Give it a wiggle and see. Mind you you would be losing boost but its worth a look anyway.

If you are near stirling PM me and you can come over, but shout at me when Im under your bonnet as Im likely to forget what year your car is, have a senior moment and pull the wrong hose off scalding us both whith coolant as happened once before, lol[]

 

Callum W

 

[][][]

[westtra]

Fai

Dont have a CAi but thats on the shopping list. It doesnt sound like flutter as I had this on my old LCR a few times.

Wilkey

Unfortunately not near stirling. It dont sound like a mooing, rich Cullenmin is home tomorrow so will get his opinion to see what sound he thinks it makes. Also will try get a sound recording. But doesnt sound like a boost leak either. No hissing etc

Yeah it comes from drivers side. Its not a constant scream just a little scream/chirp every time its nearly at full boost which makes me think its just the sound of the wastegate closing. Have checked and its not wobbling. nice and tight. is the pipe an extra vent for the wastegate? as can figgure out what purpose it serves.

Is the boost solenoid under a black cover infront of the driver side strut? may have a look at cleaning this tomorrow. Is there anything that can go wrong bar puting the hoses on wrong?

Cheers

Mark

[westtra]

anybody else?

[fai17]

Will need to hear it before i can make anymore guesses.

[Andy UK300]

i can get mine to do it pretty constant buy

just hitting 1bar boost on part throttle.sounds like a screech then.

when i do it quick though its like a chirp.think mines is a job for the

rolling road so can listen  [:S]

your car is leaking boost, the BOV probably hasnt formed a tight seal.

[westtra]

Will need to hear it before i can make anymore guesses.

have the highland meet on sunday so hopefully someone there will know what the sound is