Help me diagnose a noise.

[Diagro]

Hi

There is a noise that's driving me mental, i cant find where its coming from, nor can 2 garages.

Since i have the DPF Gutted and a remap a noise had started to creep in, at the start it was not there, then a week later it started but minor and now its there all the time when accelerating. Also i should add, this noise isn't making an appearance when revving at a standstill.

When i accelerate a noise i can best describe as "Grinding" makes its self known. Two garages say its more of a rasp, coming from the back so must be the exhaust.

I had a custom exhaust made for the car and fitted to try and remove the noise, makes a nice sound when revving, but this bloody noise pops up and is now worse after the new exhaust... Possible that the removal of a silencer has made it louder? Seems like a waste of money this new exhaust.. then again its Stainless Steel so i don't mind.

The only thing i can think is that its the DPF making the noise when lots of exhaust gas passes through it, causing something to resonate or vibrate making this noise... left over filter material?

What would you think it could be? I cant get a video as it doesn't seem to show up on a video, but it is loud enough to overpower the engine noise and can be heard with the radio on. Not to mention it sounds horrible from outside the car.

What do i do?

Edit:
Its a Mazda 3 2.2d 185, Has been mapped to 210PS/475NM

 

[Diagro]

After some research it looks like an engine mount or exhaust join issue. When engine tilts under loaf the exhust joins may give and produce a gap hence the noise.

It's booked in with the tuner who did the dpf and map now, they can't see it till next Saturday thoughso iI have to live with the mental exhaust grind till then.

 

[Diagro]

Whats the reason for actually gutting a DPF?

It was regenerating every 200 odd miles. Costing a fortune in fuel doing so. Turns out it's been cleaned by a third party at least twice based on the chemical stains found on the filter medium.
so was basically screwed.
Mazda wants 1700 for new dpf fitted... yea no.

with the thing gutted you get better exhaust floe, much like removing a high cell cat. Better mpg too.

 

[Diagro]

Im not discussing the DPF here, I dont care about that.

Went to a garage today. They diagnosed it as potentially an Inter cooler / Waste gate issue.
They said it sounds like the Waste gate is opening up just as the turbo is around 50% boosting. and then just exhausts the air with a horrible air/exhaust/raspy noise.

This is something thats 100% covered under the Carselect warranty so meh its being fixed monday

 

[Diagro]

Mazda 2!!? How dare you, this is a super special top spec, Mazda 3!! 2.2 litres of diesel fury

Yes! HOW DARE HE!

Sounds like your Remap is working well then..

I look forward to the next instalment of your Racecar Mazda 2 diesel hatchback story.

To be fair, the Parts failed now rather than later when its out of warranty. Not an issue.

 

[Diagro]

Chances are the remap is pushing the turbo too hard, the warranty is likely to have a clause excluding remaps/ECU modifications.

Possible. I will ask the tuner about that.

Regards to warranty, garage wont be telling them about any remap or exhaust mods..

 

[Diagro]

I suspect they'll notice the exhaust!

Who? The Warranty company?
Exhausts are in their exclusions list anyway so why would they care?

Also unless its a major job they wont even come look at the car. Simply just send me the payment to cover the bill.

 

[Diagro]

I wonder if you are hearing the sound of the internal wastegate opening on the turbo, its normally almost undetectable - but i have had some cars where a stainless exhaust amplifies it and significantly changes the tone of the exhaust.

Does it sound anything like a quieter version of this :
https://youtu.be/ObraQP1dUxA?t=14
(And yes, I know it won't sound exactly like this meaty external wastegate - but the character of the sound is similar)

Yes and no to the sound.

Much the same BUT now its when ever the turbo spools up the sound happens and boost falls through the floor.

Also this was happening before i had the exhaust done. And has just got worse over the past few weeks.

Its puffing out some smoke too, so the garage thinks its a Boost leak or issue with wastegate or intercooler.

they are doing a "smoke" test on it monday first thing so if they need any parts they can source them right away.

 

[Diagro]

So between the wheels, remap, new exhaust and whatever has gone wrong now, you probably could have had a MPS, instead of a barried dagdag

Barried? Sorry i take offence to that.

I have only put an MPS spoiler, MPS wheels and some wind deflectors on it... All things that are NOT barry... How rude

 

[Diagro]

For the sweet love of mercy, check the turbo compressor bearing, please!

Take the intake pipe off and see if the compressor wheel wobbles around the centre (tiny movement is OK) or if the blades move backwards and forwards (in/out at all). If it does either then the noise is the wheel hitting the sides of the housing which is VERY bad and would explain every issue you are having right now (noise, loss of boost etc).

Here's what the amount of movement from a bad bearing may look like (moves side to side)

or this -

or worst case -

They said they will check the turbo when they have it all in bits to test other bits.

 

[Diagro]

Isn't it illegal to remove the Dpf? There should be stricter laws on things like this as its not fair that tractor engines get to pay stupidly low tax when they are far worse for humans health with everyone getting them mapped and dpf's removed.
For all the trouble this car will probably bring Op as others have said should have just got the MPS

An mps would also potentially throw problems.
drink far more fuel than the 2.2d and cost 3.5k more in the first place for an older one.

I like the diesel engine. 50mpg helps

 

[Diagro]

+ a remap and stainless exhaust on a diesel.

Certainly getting into Barry territory.............................

LOADS of people get their diesels mapped. No reason not to.
nothing wrong with a stainless exhaust too if not made for extra noise. They do give the option of silencers you know?

You just sound a bit silly.

 

[Diagro]

Yep, another vote for Barry. It's a shopping trolley with a Diesel engine, nothing MPS belongs anywhere near it

I would agree if it was a 1.6l diesel.. but it's not. Muppet

 

[Diagro]

You're all joking right? Its a 2.2D Mazda 3 with a few subtle modifications to aid the remap which has seen it up to 210PS, and has a few MPS parts thrown on to make it look a little more sporty.

Sounds fine to me. Not in the slightest bit barry, and potentially quite a nice drive. If you think that is barry, you have no idea what that means, and you sound a little bit idiotic. There is nothing wrong with a performance diesel... They offer a great balance of flexible and immediate torque, fun, and fuel economy. Perhaps the OP doesn't want a car that struggles to achieve 25MPG?

This is all beside the point anyway, the OP has asked for help and opinions on what the issue could be, not for you to all act like a bunch of know-it-all jumped up elitists and tear into him about modifications he has made to HIS CAR which YOU might not agree with.

@ Diagro - sorry that I can't help with the issue you are experiencing, but I had to voice my thoughts on some of the stupid posts in here...

thanks chap

 

[Diagro]

Indeed

Could a MOD close this thread please.

Thanks

 

[Diagro]

So we essentially have a bloke her who couldn't afford the MPS?

Instead he got the diesel, remaps it, guts the DPF, is fitting a SS exhaust? Sounds pretty chavvy to me.

I could afford the mps. Simply wanted a car with better mpg than the clip 172 I had before.

I got that with this mazda. Faster than the clip and near double mpg.

I then have fitted the bits that mazda sell as options... and had an exhaust custom made for the car.

And I had the dpf gutted because it kept regenerating... along with a remap to boost the performance (like countless others do to vw and bmws...)

So your calling lots of BMW owners chavs too? Have fun

 

[Diagro]

I'd actually say there are more chavvy BMW owners out there than any other manufacturer, why do you keep comparing to BMW anyway?

I still can't get over gutting the DPF rather than fixing (under warranty!!!!!) whatever underlying problem there was with it.

Dpf is part of exhaust.
From what I can see that's not covered under the warranty.

also if it was replaced it would still be an issue in the future.

And I wanted to remap the car anyway, the Dpf removal only added 75 to the cost! Common sense no?

Can we agree to disagree here?