Strange noise whilst engine under load???

[supermonkeyballs]

Firstly I apologise if this is in the wrong section, I did see others asking for the knowledge of the group here hence my post location but I am new to the forum and I don't really have many other places to turn. I can move the post if its in the wrong place but anyone's help/knowledge would be greatly appreciated.

 

Now I should add I have tried reading up on the problem else where and I am at a point of either thinking its transmission related or turbo related, the local garage are stumped as well but they aren't scooby specialists and due to my location in the county it may have to go to Plymouth but I am worried about the drive up there because of distance, however I don't have a great knowledge of turbo cars, nor 4 wheel drive transmission systems.

 

I'm not a complete novice either with most things maniacal and have changed complete engines and gear boxes in the past but this has me a bit stumped, I should add that I was a BMW man from the age of 19 and in January this year I saw the light so to speak :).

 

Now my problem is with my first generation Subaru Impreza 2.0L (1997 UK) has this very strange noise whilst the engine is under load and only when under load, its fine at low speeds,l no noise and out of gear the noise stops straight away, so soon as you pass 30 MPH it starts and I can get the car to 70 with this noise whirring away quite high then as soon as I engage the clutch to disengage the gear, the turbo dunps and the noise stops, so its not brake related, nor steering and I lean away from transmission because its aright in gear at lower speeds, but then the car is under far less load at lower speeds to do things, that being said, me and four wheel drive cars don't have a lot of experience.

 

The noise itself only appears above say 30 MPH and the more the load on the engine the higher the pitch of the noise.

 

I will add I have had the clocks off and driven around with out them in place and still the noise was there as the noise itself sounds and feels like its bang in front of me when I drive, like in the dash board speedo area, it could of course be in the engine bay but I cant stick someone in there and drive around with them on the bonnet.

 

I also blanked/blocked off the boost gauge breather pipe as I then thought it was my piping to the boost gauge in my alpha post but I still have this noise when the boost gauge is disconnected.

 

I also cleaned the DV out which was stinking dirty inside but I still have the noise.

 

Its like a whirring noise, like a doctors drill, it increases under load in tone.

 

I'm not wanting to drive her to much at the moment but I took it out last night to get a good description in my head of what to write here today and after 30 miles it got louder, and more persistent, so it may be heat related, like the car has got hotter and then the noise increased, became more constant.  

 

I will add, prior to the noise, on rare occasions on the dual cartridge way hills at speeds of say 80-90 mph before this noise began I used to get an ECU light indication warning come up, (RED on the dash) this would only happen when if I was going up hill but not punching though the gears, like at a constant speed up the hill, sat at 80, the ECU red light would indicate, the first time this happened I stopped straight away, (along with my heart) and it cleared off with the engine being turned off, its happened more and more now with this noise happening (I have to go over 70-80MPH to get it up) but every time it does it will clear with the engine being turned off.

 

 

I have also videoed the problem which can be watched here on youtube

 

https://www.youtube.com/watch?v=G-9KnWpZh5M&list=UUqlunONtDQFehNV8-4oxqAg

 

video titeled = WRX STI First Generation engine noise whilst under load. Video uploaded for purpose of diagnostics. 

 

Any help at all would be greatly appreciated.

 

Thanks again 

 

Richie.

[Scooby Pete]

only thing I can think of the is Turbo's bearings, the whine seems tied to the turbo.

Hopefully one pof the Techy Guys or Scooby Spoecialist will chip in with the correct Diagnosis

[savage bulldogs]

if it doesn't do it when you engine break id say it wasn't transmission related.

I'd eco turbo related , Sounds a bit like a boost leak to me .

Have you done a ecu code check by plugging in the connectors under the dash ?

When you had the boost gauge connected what did it read ?

Did it hold boost or drop off ?

[supermonkeyballs]

Right firstly thank you for the comments, secondly I didn't know you could plug in the connectors under the dash??? I have fault read an old Vauxhall Cav GSI red top before using a paper clip and it flashed lights which related to what the code/problem was, I take it this can be done on my WRX STI??? I was under the illusion that it had to be plugged into a special diagnostics machine as the local garage don't have the right connection for the ECU to be read (apparently).    

 

From this I gather I can read it myself?

 

and I haven't thought about trying the engine/clutch to brake/slow down the car (whilst in gear), that would indeed show if its the transmission or not.

 

Is boost leakage going to be hoes alone or a magnitude or checks???

 

Sorry for all the questions. 

[supermonkeyballs]

Right just found a how to guild on here (that shows me not to take peoples word for things about what I can and cant do), so thanks for the point out about the fault reading, I will get on this right now as she's sat out side and I miss driving her. Will post my findings.

 

Thanks again.

 

Richie

[savage bulldogs]

No probs with question's we like to help if poss.

I'd start by checking the main boost hoses after the turbo and under the tmic (assuming you're not running a fmic ).

There's a link on here for the self code check (somwhere lol)

It's much like the paperclip gm test .

[supermonkeyballs]

Right I have fault read the ECU using the green and black connectors and I have the following codes.

 

A No 23 which is a Mass Air Flow Sensor Circuit.

 

A No 32, which could be one of 3 (PSB).

 

32 A/F Sensor #1 System

32 A/F Sensor #2 System

32 Oxygen Sensor

 

Either way its safe to say it has an air flow problem.

 

As for the turbo I drove the car and I tried breaking on the clutch, using the engine to slow down and what I have noticed is that upon dump (dipping the clutch) I can keep the Revs at roughly the same level whilst decelerating the engine on the clutch, then re-engaging the gear, if done quickly the car will be in gear at pretty much the same gearing and speed as previously just for that couple of seconds with no noise, because the dump has released the pressure and stopped the turbo spinning/spooling by dipping the clutch, after two to three seconds (which I think is enough time for re-pressurization) and the turbo to re-spin/re-spool the noise is back, so I think its the turbo. or something connected to the turbo, I have checked all the connecting pipes and have tightened things that looked loose but I found nothing to obvious.

 

What I'm wondering now is how grand in the scheme of things the Mass flow air meter is or these A/F Sensors or the Oxygen Sensor, will that cause adverse wear on the turbo.

 

Clearly I need to get the air flow problem sorted and also, somehow get the turbo sorted.

 

What I have also seen is someone at some point has used sealant instead of a gasket on the turbo.

 

Any thoughts would be greatly appreciated. 

[supermonkeyballs]

P.S I'm not running a front mounted inter cooler  ;)

[stants]

Hello, sorry to hear of your problem,

32 being o2 sensor, when have a look at the turbo just behind the housing in the exhaust down pipe is the main o2 sensor, have a look at all the wiring and make sure it's in place properly and intact. If it's dying it will flash up a cel light now and then. But should not make a whisteling noise unless it's not done up properly and air is escaping under load ? Seems odd but I suppose anything is possible.

You can buy generic sensors for a fraction of the cost as a genuine subaru one but I've been told these dont last.

A new subaru one from an internet specialist will be about 140ish. I wouldn't even call subaru unless your sitting down and want a laugh.

[supermonkeyballs]

Thanks Stanton, I will have to check that tomorrow now as lights fading.

 

I take it you don't know anything about the 23 Code? Air flow mass meter?

 

Either way thanks for the advice.

 

Richie.

[stants]

Sorry I've been reading on my phone and for some reason I couldn't see anything in the post with the code 32 all the text just dissappeared.

If the maf or o2 isn't working properly it will either run rich or a lean the ecu will compensate for the problem, easy maf test is to run the car and disconnect the maf. If it stalls it shows the maf is more or less working properly. Not exact and if you have a multi meter you can check the voltage for a more accurate diagnosis. When you pull the maf you'll get another cel come up.

Has the car got an aftermarket dump valve on ? Could be the root of your problems, they don't really like them and prefer the oem recirc valve

[savage bulldogs]

I think most maf failures show a rough running or holding back as symptoms . It still could be a boost/air leak issue (due to the noise)

As air coming in is measured by the maff .

Air in the inlet is measured by the MAP sensor (manifold actual pressure) .

And gasses on the way out by the o2 sensor.

Any loss of air between these sensors would show a fault in the air system .

Check the black plastic intake pipe (from turbo to maff) tmic pipes , dump valve (and fittings) for splits .

Once you manage to solve the noise issue I'd then do a ecu reset which might mean you don't have to buy any sensors .

[supermonkeyballs]

Savage, not to blow smoke up your bum but you were bang on with what you said!

 

Me and my brother got about the car today and firstly removed the top inter cooler, upon doing this and turning the inter-cooler upside down I found that some Muppet at some point in time thought it would be wise to only have 3 bolts underneath it. The Top Main Inter Cooler should of have four underneath (the four bolts job is to create a seal between the two metal connectors which hold the black Y piece in place). Clearly it should of had four there, plus whoever it was had thought that by shifting both gaskets to the one side, it would mean it wouldn't need a bolt (two bolts per holder) to make up the space in the gap which was created by having a bolt missing.

 

How some people cut corners on what was a 39p bolt is beyond me but after a new bolt being fitted and both gaskets now being in place and sealed as they should of been, the road test showed that the noise is completely gone and everything is running as it should do.

 

I will add I looked at some videos about MAP Sensors, Maff Sensors and O2 Sensors and I actually have to admit that now I know what I'm looking for that my lambda O2 Oxygen Sensor is actually missing. Well its been blanked off and removed, which going along with the fact that the car was de-catted when I first got it, it all makes sense.

 

So now I need to get a new sensor and clear the fault codes and go from there.

 

Thanks everyone for there help.

 

The noise eventually only cost 39p to fix, which has to be a result  :)

 

Thanks again

 

Richie   

[stants]

Great news mate [emoji16] glad it was an easy fix, looks like the previous owner was a complete muppet when it came to car maintenance !

Why you'd cut corners is beyond me,

Has the car been remapped ? Not sure how it's running right without the sensor, least things are looking up

[supermonkeyballs]

Stanton its been a journey with that car lets put it that way.

 

I knew it was loud when I brought it but I didn't think it was decat, plus it was low so it was hard getting my noise under it. I should of spotted the blanked O2 sensor but to be fair I would of thought it would of been further back on the pipe.

 

It also to my horror once on ramps back home in Cornwall had had the springs cut to lower it instead of lowering springs, and one of the cut edges of the spring had punctured the cup in sits in, so its had new suspension and its also now has a cat.

 

I also had alarm issues which I have now rewired.    

 

Now today this 3 bolt issue, but as mentioned 39p later and its all sorted. 

 

It just seems to off been run a bit on a shoe string at some point but Im slowly bringing it up to a standard it should be.

 

I have no idea about the remap mate, I didnt have a great deal of paper work with it, what makers you think its been remapped then, as you mentioned you dont know how its running with out it??? is that a factual point that it shouldnt run with out an O2 sensor in it??? 

 

And yes for now things are at least quieter (well no doctors drill noise anymore)  :)

[savage bulldogs]

Glad it was a easy fix fella [emoji41]

Did you do a ecu reset ? ( think the code check guide covers it)

Early classic's (pre 96) have the o2 sensor just before the upipe , are you sure it's not been relocated to there or further down the downpipe ?

I think standard boost shouldn't be anymore than 0.9 bar on a 97 sti . if it's more than that and there's no sign of a manual boost controller, it's probably been remapped.

I'd get on a local rolling road as for the sake of £50 it will let you know everything's running ok .

[stants]

I'm no expert & maybe someone can answer better than me, but when you decat a remap is needed otherwise it can cause issues, if the air filter is standard it may be ok but if both are changed it will deffo need one as the air/fuel mix will change,

Unless you have some paperwork determining this will be hard as the 97/98 cars are a ball ache (I'm in the same boat) subaru decided to make the ecu virtually impossible to crack so you need an aftermarket stand alone ecu or a duaghterboard inserted into the original subaru ecu to be able to map, easiest way to check is lift the carpet in the passenger foot well and see what you have, the esl daughterboard won't be visible but an aftermarket one will stand out,

Is scooby bits located in your part of the world ? Maybe worth popping by and having a word,

[stants]

Doh got broken off for my dinner come back and sav's answered so ignore my waffling on !