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Hi Guys,

This is about my Swift Diesel, its 1 lakh 57 thousand kilometers run, 10 years old.

I am facing this very peculiar issue, let me describe this in detail, I don't know what it is related to and I will need all the help I can to diagnose it and fix it.

When the engine is revved to 2800-2900 rpm, there is a peculiar whining kind of noise which appears, it looks like a whine but it could be a whoozing sound too, I am not sure! I can't seem to figure out. The sound goes away after 2900 rpm till whatever RPM i rev it too, its only present in this rpm zone. If I drove at 120 which at this rpm, the sound stays till I drive at this speed, either I have to slow down or speed up for the sound to disappear.

Surprisingly if the same thing is tried while in neutral, there is no sound at all, even if the rpm's are held at that range, it sounds absolutely normal.

The car is accelerating perfectly, there is no smoke from anywhere, the pickup is same as it used to be

Any pointers on what it could be? I am going nuts just trying to trouble shoot this. Also it would be amazing if there is a hands on and smart mechanic/service station whom you know of who would help me resolve this.

Mods: This is a very peculiar issue, hence I needed to create a thread for this.

Whining sound could be wheel bearings? Try Joe from Nakita motors listed on t- bhp directory. He is a ex- maruti employee and loves to work on all Maruti cars. He is located at Bandra though. Kindly call prior to visiting him.

Thanks for the reference Sumit, I will call him and take an appointment,

No its not the wheel bearing, its engine rpm dependent and not speed dependent.

For example, if I reached 2800-900 rpm in 2nd gear, it would still make the sound, 3rd gear, it would still make the sound, same with 4th and 5th.

Sounds like an engine mount issue to me. It happened in my previous car where car would vibrate and make weird sounds in a narrow rpm range in every gear. Check all engine and gearbox mount points, bushings get ineffective/ worn with age and cause the engine to transmit vibrations to the chassis.

Your car's clutch is going bad. This whining noise that appears at a particular rpm band (mostly early) means that the clutch is slipping.

Try to focus on how the car picks up pace, although you might not be able to notice it as the 1.3 multijet is already jerky to drive (as the turbo spools up).

Also, your car has already seen some miles, so it's better if you get thr clutch checked.

It is possible that your turbo is making that noise due to worn bearings. Turbo on a diesel engine will usually not spool if you rev your car in neutral. Turbo will only spool under load. That explains why you don't hear the whooshing when you rev your car in neutral. Best to get it checked at a good FNG.

I beg to differ as in my car(Linea multijet) with the same engine, the wastegate release sound can be heard while revving in neutral, which means the turbo does spool.
Is there any vibrations associated with the noise?
if yes, within that rpm range, some component's natural frequency matches the vibrations at this rpm range. I'd look for vibration damping devices like engine mounts and also flywheel and clutch misalignment. (Check pressing the clutch while in gear at that rpm). Is the noise present with the AC on/ off? (I remember reading EGR valve actuation is dependent on the AC.)

If the whine is more like air leakage or faint whistling, look for leaks in EGR circuit. I'm sure you'd rule out turbo plumbing leakage as you do not experience loss in power or smoke.

Edit: Just noticed that your might be a BS3 model, then you can disconnect the EGR and check.

PS : I had a similar noise around 2k RPMs after the timing chain and clutch kit change which went away after 5k Kms. It happened only in a small rpm band.

Your Linea and Swift probably share the same engine, however they may be in different tune states. Also Wastegate noise does indicate that it is opening and allowing exhaust gases. However in neutral and under no load they may not be enough to spool the turbo to actual rpms as compared when there is load on the engine.

A cursory Google search with "Does turbo spool in neutral" will throw up a number of good articles to explain what I suggested.

Having said that it may be something related to vibrations as you said. However the initial comments of a whooshing sound indicate more of a air pressure kind of sound in my opinion.

Hopefully a check up at a garage will sort out the real issue.

Could be the plumbing related to turbocharger and/or the intercooler that's letting some air escape giving you that sound at that RPM. Get that checked.

Do you use an FM transmitter? Have you checked if the sound is coming from the speakers?

Have you got the gearbox and clutch checked? Since it is speed and rpm related these are the most likely culprits. Wheel bearings usually gives a hum and rarely a whine. If it was only RPM related then you need to check the engine pulleys and bearings checked.

That sounds like a fair point, the engine mount was removed too when the timing chain job was done, so this could be the one, let me get this checked.

Hey, I doubt it could be the clutch for the simple reason

1) The clutch is only 20 thousand kilometers old, I got it changed at 1 lakh 37 thousand km
2) The clutch is not slipping at all
2) There is no judder
3) It's really light too

Although it could definitely be something related to the clutch where in some vibrations are being put out at a certain rpm, I will get this checked.

This could be the cause, at certain engine rpm's under load the turbo is spinning at a certain rpm at which the vibrations are being emitted from the turbine due to play and when at idle we are getting it upto that speed, the turbo is not spooling at that rpm.

Also what it could also be after thinking a lot is that there could be a leak somewhere in the exhaust side which is making itself felt only at that particular rpm maybe?

I think the exhaust gases which spool the turbo are more under load than under idle revving for the simple reason, that when I jacked the car up and took it at 2900 in 4th gear, I had to only depress a fraction of the accelerator than what I would depress when the car is in loaded condition, this means less fuel is going in the combustion chamber at that rpm in the unloaded condition which translates to less exhaust gases being released which means the turbo spooling in unloaded condition will be under less boost than in loaded condition.

I will check the engine mounts and the flywheel too. The noise is present with AC on and off both.

I think your EGR leak point sounds very fair and a good idea, let me disconnect the EGR circut and check if the noise is present or not. I am going to get to diagnosing all this this weekend.

This noise happens for me in such a narrow rpm band too, like 2800-2900, after that it vanishes

Thanks for all the suggestions

Yes, I will get this checked too.

No, I eliminated this possibility right from the first go.

Its more of RPM related, as speed is just a byproduct of me putting it on load condition. I will remove the belt from the entire pulley mechanism and go for a drive and see if anything changes.



Sorry for the late reply, I had been to Mahabaleshwar for a road trip over the weekend, I drove the car from Ghatkopar to Dombivali in early mornings and we took my friends Ertiga to Mahabaleshwar rather than my Swift.

What I could observe while driving till Dombivali in the dead of empty roads was, the sound is coming from somewhere near the foot well near the clutch pedal or maybe the firewall behind the dashboard. The exhausts rests below it, so does the turbo and EGR.

Anyone faced a similar issue?

Had the car shown to Navneet on Saturday, they kept the car till yesterday to diagnose with the issue was.

They could hear the noise, their technician as well as the service adviser heard the noise.

They went around looking at it from the EGR and exhaust point of view, opened the EGR, checked its pipes and valves, nothing turned out from there, checked the exhaust for any leaks, nothing there, tightened the mounts and everything they thought could make that noise, still nothing.

Finally when I went to pick the car up and went for a round with their technician, the noise was still there, he said this could probably be a gearbox input shaft noise or a remote possibility of a play in the turbo shaft.

Also he said this sounds like a bearing type of noise than a gas escape type one, I don't buy his turbo bearing noise theory as otherwise it would make an even bigger racket at higher rpm's, this just manifests itself at 2800-2900 rpm.

The input shaft it could be, he said that I should not worry and drive around till the noise gets louder, if it does get louder and that time it will be easy to figure out what it is and fix it.

The upside of them tightening everything, the car seems as good as new now sans the mild noise between 2800-2900 rpm.

Let me drive it around for a couple more thousand kilometers and see what happens.

Input shaft bearing noise goes away as soon as the clutch pedal is depressed and comes back on disengaging the clutch. Bearing noise should not be in a narrow rpm range. Show the car to someone else for a second opinion.

Some more observations when I had been on a trip to Lonavala this weekend

1) The sound sounds like when a silencer has developed a hole in a petrol car and it makes a sound, although those who have sat inside also feel its a bearing kind of sound, so on the fence regarding that

2) It comes from the centre left part behind the dashboard

3) Its consistant at the 2800-2900 rpm range and vanishes after 2900 rpm, it does not show itself below it too, but strangely when I am at this 2900 and I let the accelerator go, it makes a 'gaaann gannn gann gann' kind of sound which again could be air or bearing, not sure, vanishes as soon as it goes below 2800 rpm but the irritant is that it stays for a few seconds when in top gear as the speed and rpm rise is slow, someone sitting in the front can hear it

4) Absolutely no loss of power, pickup, top speed, nothing

Any more diagnosis? Should I get a Maruti engineer involved? If I go down this route it will be more of a complaint against a service station and its inability to solve this issue rather than 'asking for help' as the reporting mechanism itself is a complain mechanism, does anyone know a Maruti engineer whom I could talk to?

All advice/help/suggestions/options would be highly appreciated.