I have got this strange whistling noise that only happenes just before 0 boost i.e the engine not making boost yet. IT sounds like air being sucked through a very small hole but not sure where

Its not the same sound or pitch as the whistle the turbo makes so its not that.

We Took the Throttle off to clean it out becuase of low idle problem and when it was put back it makes this whistle noise. (it wasnt there before taking off)

I thought it might be the pipe that goes from the Aux Air Valve to the underneath of the throttle but checked the pipe and the inner sleve and they are both ok, so doesnt seem to be that.

Have checked all pipes and no splits or holes found.

Could it be the Aux Air Valve ? is there anything inside this that could make a whistle sound or could it be broken and whislte?

Anything else to check that could cause a whislte noise?

 

BTTT

 

BTTT anyone with any ideas ????

 

only thing i can think of is an airleak

its conceiveable that you could have damged the AAV and this is now vibrating and causing a whisle, but if that would happen (highly unlikely) then i doubt you'd be able to hear it as itd be so quiet!

have you checked and re-checked all the vac hoses etc. around the inlet manifold area? are you confident that the main boost hose from Xover pipe to TB is seated 100% securely?

try spraying carb cleaner all round the inlet manifold at idle and see if the revs change at any point (dont use WD40... carb cleaner is combustable so the revs should rise if any manages to get into the engine )

 

Inlet manifold gasket ?

 

a vacum hose is leaking maybe?

 

have you got a dump valve? you can make it whistle if you play with the throttle and just find the point between open and closed used to make my cos do it all the time, makes a really high pitched "wheeeeeeeeee" might just be that

 

mate had the same problem on his nisan 200sx, was delaying on boost slightley as well, turned out to be the dumpvalve sticking/ weak spring. so it was blowing air out at high speed for a second as it came on boost.
might be worth cheacking?

 

Hmmm, I've been having a serious problem with my Focus not holding boost (keeps peaking then dropping ) whilst under load + have heard a strange whilstling noise a couple of times. Could have a leak too/dodgy dump valve (standard re-circ)?! Don't know a great deal about turbo's etc though but will have a look, how will you know if it's the dv??

 

I was gonna say dump valve too..............

 

most decent dv's can be taken apart, we just striped it cleaned it with loads of wd40 and pulled the spring a bit so it was a bit stronger. just dont make the spring to much stronger

 

Its defo an Airleak IMO.

It will be something not tightened properly, or a nipped hose. Inlet Manifold to Throttle Body gasket, theres a classic!! Did you use a new one? Are the nuts tight?

Could even be air getting between the plies of a Silicone hose if you caught the edge as it went back on.

 

Could it be that rubber O ring you were talknig about the other day mate? And I have got one if you want it, PM me your addy

 

...that will exclude the standard Bosch item then, time for an upgrade!!

 

Andy doesn't have a poof valve on his car.... surprisingly


BTTT for him.


Mr C - I suggested he converts to Omex to get rid of the whistle, what you think?

 

pmsl, thats a surprise as he has that truely gay stick on petrol cap

 

Ild say christian is right th to inlet

 

Either throttle to inlet gasket or the inlet manifold gasket

 

We didn't take the inlet off, just the throttle body...

 

my car does the same!

did it on old engine, does it on new one! Only gasket i havet changed is throttle body to inlet

 

There ya go then!! They are sods for it. The Ford gasket goes brittle with age and normally it will come out in pieces. Its one of those items that needs replacing every year IMO.

 

A new gasket was used for there, but 2 out of the 4 studs came out with the nut on them, because somebody never put any WD40 on the night before, could that have something to do with it?

Rick - Aren't you worried about the fueling side of things with it?

 

Tony - no, as it'll be a miniscule amount of air going in, plus ive driven it with AFR equipment on and all good

 

As Said no Dump Valve fitted, new throttle to inlet gasket was fitted.

Im stumped because it defo sounds like an air leak when driving it but cant hear or see anything when car @ idle

Guess i'll take throttle off and put a smear of sealer round the gasket to insure a seal is made.

 

Remove the Idle speed screw, wrap a little PTFE tape on the threads(plumbers tape) and replace

 

You can do that Andy

 

Before ya do it if ya wiggle it the whistle wil probably alter a tad if it is that! They do whistle from there

 

don't worry about it mate, some people would do anything for a good chatter

 

Just look in that area and you should find the problem.

 

Have looked in that area and found no problem, hence this post me asking for help

 

You must be joking, right?

So the fact that the AFR is right makes it OK?

Under boost, it will be air coming out anyway.

 

Andy, when you say you have 'looked' what do you exactly mean?? Have you tried Jims idea of spraying Card cleaner all over the area? If you dont have any, then try WD40 or a solution of washing-up liquid and water.

Alternatively, bring it to us and we WILL find it.

 

It had low idle. I take it after cleaning the idle screw was opened to make it idle faster,,,,this makes it whistle more. Worth a try. All 3 of my RSTs have all whistled from the idle screw.

 

Yes Mr C i have tried water and washing up liquid over the inlet to throttle gasket and it didnt suck any in or cause it to sound any different. have checked all hoses that go to or from inlet or throttle and nothing seems to be split or have a hole. Might try the carb cleaner If i cant find it this weekend good to know i got an option for somewhere to bring it, cheers Christian

Some more info:
The whistle noise CANT be heard at idle but if you blip the throttle very quickly theres a slight chirp/whistle for a second. It can only be heard constantly when driving under load and just went it comes upto 10 in.hg VAC on boost gauge (just before 0 on boost gauge).

Going to try and bypass the Aux Air Valve with a piece of pipe. Will the car run without the Aux Air Valve, i guess will be lumpy until warm? Just want to run without it and see if the noise stops. least will remove that from the list if it makes no difference to the noise.

Lee, I have checked the idle screw and tried screwing in and out to see if it changes the "chirp" heard when reved at idle or the constant whistle when driving and it made no difference

 

Andy now youve said it doesnt do it at adle then it wont be that screw My old s2 whistled like your describing and it was the inlet manifold gasket. Cant think of owt else TBH

 

Christian - yes

How much air do u think is coming out?! It'll be a a fraction of a percent of the air entering the engine. It's irritating more than anything - the fact the car has covered so many miles without a problem is proof of this. I will sort it though - when i can be bothered

 

Its just that I was under the impression from some of your past replies that your engine is going to be something a bit special (?) and I was a little surprised that you would let something as silly as a paper gasket remain in that condition.

Its a bit like building a spangly engine and using a second-hand exhaust manifold gasket, you just wouldn't do it IMO.

As for how much air is coming out, you would be surprised. In terms of pressure. We recently diagnosed mine to have a leaky Injector O-Ring and I was losing around 10psi through that. I dont think that the TB Gasket would cause it to lose that much, but its so worth changing it. Also, if mine were found to be knackered, there is no way I would drive it hard until we checked the MAP.

 

I have fixed the whistling noise!!!!!

I started buy spraying carb cleaning around the inlet to throttle gasket but nothing, then tried all the pipes to throttle with carb cleaner and nothing. spray carb cleaner around the idle screw and still no change. I took the piping off for aux air valve and bypassed it and still no cure the noise was still there.

Stripped the throttle body off again and inspected the surfaces for sign of a leak but nothing (they were smooth no lumps or bumps of old gasket ). Did the same for the surface to the inlet and nothing there.

So cleaned the surface of the inlet and the throttle body with fine wet and dry and then re-assembled the throttle but this time using a smear of blue ford gasket sealer. Took idle screw out and put a smear of oil on threads.

Run it up and set the idle again and take it out and NO WHISLTE NOISE

Cheers for everyones thoughts and advice