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-   -   Turbo noise in my 37k old Hyundai Verna! Advice requested. (https://www.team-bhp.com/forum/technical-stuff/113474-turbo-noise-my-37k-old-hyundai-verna-advice-requested.html)

Hi All,

I'm in need of some advice/suggestions here. My Hyundai verna CRDi is 37k kms old and is a Dec 2009 model. Recently, after a routine service at 36k, we could hear a humming noise in the cabin which increases linearly with the RPM. My initial hunch was that it was from the Turbo, which was confirmed later by the technician and SA at Hyundai A.S.S.

They drove the vehicle and confirmed the noise. They intended to record the noise when I leave the vehicle for inspection. They took pictures under the hood. Now, I am supposed to leave the vehicle for inspection on Wednesday where the turbo will be removed, the intercooler and EGR will be "cleaned". If the noise still persists, they would go ahead with replacing the Turbo under warranty. Yes, I have opted for the extended warranty.

My queries:

1. How serious is the issue? What are the chances of a mandatory turbo replacement?

2. Are there chances of the humming noise disappearing after the "cleaning" process mentioned by the SA?

3. How complex is removing the turbocharger? Will the engine be dismantled too?

4. In case the turbo has to be replaced, will all the charges be covered under warranty (Including labour)?

5. What all should I be aware/cautious of before I leave the vehicle for inspection?

6. In the present state, what are the chances of a turbo failure? The SA confidently said the turbo will not fail easily and I can still drive around.

7. In the case of a turbo failure, what are the ill-effects on the engine?

Experts Advice please:

For replacing the turbo, no need to dismantle the engine.
Do not drive with faulty, noisy turbo.
If turbo gone, replace it.
Less chance that humming disappear with cleaning. With faulty turbo it might be pushing in dust and debri into the engine.

The clearances in the turbo are very less and hence the lubrication of the shaft is very important for the long life of a turbo. If the turbo is making a noise, its better to replace it rather than repair. While driving just make sure the you don't give sudden load on the turbo by accelerating too fast on a cold engine et al.

Do report back after finding from ASC what was the real problem.

Cheers

Hi,
The most propable source of noise from the Turbocharger is the journal bearing around the rotating shaft. Owner's manual usually insists the driver to leave vehicle at idle for some time immediately after start & just before turning off. Failing to follow this practice can lead to a early failure of this bearing and possible after effects will be engine oil leaking into the cat-con, tailpipe or into the intake manifold.
Usually this bearing is not replacable, still you should feel yourself lucky if you get rid of the noise up on cleaning the turbo & intercooler. You will get to know of oil leaks once the unit is removed and intercooler is checked.
-Ilango

Yes I make sure the car doesn't move an inch before it is left to idle for about 45 seconds to 1 minute. Even after that I'm very light on the throttle until optimum engine temperature is gained. The same is followed before the engine is turned off! I can vouch this is not a result of faulty driving!

On what basis has the SA concluded on turbo failure ? please ask the SA for a technical explanation.

Are you facing any other problem while driving, any loss or variation in power delivery at any RPM ?

Hyundai CRDi turbos are pretty robust, so i would really doubt a turbo failure at 37 k kms.

I would partly agree to this point. My own car has completed 47K kms without a shadow of turbo trouble (fingers firmly crossed!:)) but I've heard of Hyundai CRDIs with 30-35K on the odo getting turbo/injector problems. Always thought these were badly maintained cars, but Added_Flavour seems to be really caring about the start/stop schedule. Even I don't follow it this religiously:D.

As I have said earlier, the SA hasn't concluded on a turbo failure yet. He is willing to inspect. But he was greatly hinting that the turbo might have to be replaced. Of course the thumb rule is that it can't be repaired!

I'm not facing any issue as such except for the humming noise! Absolutely no power delivery issue. The turbo is effective and the car is as fun to drive as ever! I feel the humming noise is gradually increasing - I am not sure if it's actual or I'm being paranoid!

Even my verna developed the same humming noise at around 40K kilometer. I found that if I drive with AC on, then only it makes a hiss noise otherwise it's fine.

Are you driving with AC on or off?

A humming sound could be due to a small hole or crack in the silencer pipe too. Why do you sespect the turbo?

No offence here, but, did the SA suspect the turbo after you mentioned about your thoughts about the failed turbo? Well all i am sayiong is that, it could be things other than the turbo.

Running of only 37000 kms is too early for a turbo to fail unless the engine is really subjected to some harsh treatment. Also the failure of turbo should so other effects like lack of power, black smoke and oil consumption. Try opening up the inlet pipe to the turbo inlet and inspect for oil deposit. If you can access the turbo shaft ( make sure the engine and the turbo is not hot ) please check up for the play in the shaft. If there is no play or engine oil deposit i dont think the turbo is a problem.

You have not mentioned anything about the acceleration in your vehicle or the smoke. If the above both of them are ok the turbo is absolutely in perfect condition.

The reason for turbo failures are:
1. Lack of lubrication.
2. Clogged airfilter.

Please let me know.

Thanks guys. It was very evident when we heard the noise under the hood that the source was turbo. The noise was present with and without AC.

Ultimately the turbo charger was replaced by Hyundai under warranty. I was not asked to pay a penny even for the labor. The new turbo charger comes with a 6 month warranty.

Mixed feelings that the turbo had to be replaced so early, but the whole process was very smooth and hassle free!

@CRDIsamir: Yes there was unusually high black smoke emission. I couldn't see much difference in the acceleration yet, but the humming noise was definitely increasing day by day!

Hi Guys,

I am running a Getz CRDi which has run about 41k . I too religiously warm up and idle for more than a minute every time befor start / Stop. The power even today is superb and very smooth and linear, but I am observing a lot of black smoke during heavy acceleration while overtaking in especially 3rd gear. Is this normal or there could be some problem ?

I am running with Mobil Delvac MX and K&N filter. Appreciate your inputs.

MJK.

Interesting! Glad to hear about a hassle free warranty replacement, that too a part like turbocharger.
How many days did they take for the replacement ?

Hi MJK,

How many kms have you done after cleaning the K&N filter ?