Hi my evo sporting 1.4 multiair is mapped to 162bhp. Since then its had a forge induction system and a tmc power pedal tuning box. The last thing ive done is have a turbo back 2.5in custom made exhaust with 100cell sports cat, straight pipe to small high flow rear box. Since i had the exhaust fitted there has been a grinding sound under de excelaration. At first i thought it was the heat sheld but this has been checked today. Im now wondering if it could be the turbo fin hitting the housing. To make the sound i run it up to 90mph and come off the power. It dont make the sound at lower speeds even under hard driving. I have also tried to make the sound it 3rd and 4th with the same revs as would be in 5th at 90mph and is all good. The sound is a sort of metal grinding and is quite loud for 5sec or so. The car still pulls well and no lights are on the dash no smoke and seems in good health other than the noise. Your thoughts would be appreciated.

To be sure you have to remove the intake tube and see if compressor wheel is damaged. If yes, you have axial play on turbo and it need a rebuild.

If no, good new, noise if from other part. Perhaps check heat shield around the turbo.

Heat sheld was looked at and tied down today. I would have thought if it was the turbo it would make the sound in all gears! I did feel the blade when i installed the induction system and all was good. The cars done 50k btw with full service history. Thanks for your thoughts...

You should have someone accelerating and de accelerating and you should "hug" the bonnet in search of the noise.
The noise i had one time was from bad fitting of the wasteagte's heatshield and next from bad wiring management on top of the engine.Take a screwdriver with you to help you watch where does the problem come from

It only occurs at 90mph in 5th for most part so not easy to find but it quite loud almost sounds like exhaust is hitting tbe ground

I'm certain it's the exhaust hitting. It might be the exhaust but might also be the engine mounts, when they get old they allow more movement.

My exhaust used to hit the flat metal brace )to which the under engine dust shield bolts on to).

Ok little update i just drove the car and when its hot the noise can now be herd in the lower gears too. I floored it between the speed bumps in 2nd almost redlining and its making the sound. Its only when i come off the power. The car pulls strong and seems fine apart from this god awful sound. Ahhhhhhhhh lol.

then.. might it be the gearbox?????
what gearbox do you have?

all I can tell you is my car's a 2011 punto evo sporting...5 speed..

I can say the clutch and gear box seem fine to me. all sharp and tight imo

ok here is a link to a clip of the sound thats coming from the car.





hopefully this can help you help me lol...

that is definitely a problem with something hitting... to me it seems to be a vibration to it also .. not a turbo problem.

My advice.. get under the car and start removing the wheel liners and under engine plastic dust/water guards.
Then go out for a ride.. see if it's still doing it.
check the brace that goes under the exhaust !!!

Will do bro its going back to mij in walsall monday and im not leaving till its sorted. Failing that i will take it to amd tuning in Essex and take mij to court.

Like i told you man, it;s just some vibration, some metal thing just touched another metal thing and vibrates, nothing more, nothing less

Problem solved. Mij said a washer which attaches to the bumper and under tray. I find it hard to beleive but according to them thats the case. It took them 4hours tho. Never the less the problem noise has now gone.

Nice, thanks for the feedback !