[guyfrmblr]

Hi All,

Its been a year since I bought i20 CRDI and have driven around 30k km in it. I din't face any issues with it until last Saturday. I started the engine in the morning and could hear loud noise from the engine. The sound was like fire cracker bursts. I could also see a thick cloud of smoke from the exhaust. I immediately turned off the ignition and turned on after a minute and could hear the same noise. I again turned it on after 2 minutes and everything was normal. I then drove the car for around 80 km and it was a smooth drive. I travelled around 480 km yesterday and din't face any issue.

I again experienced the same issue this morning while cranking the car. Loud noise like fire cracker bursts, heavy vibration, thick smoke from the exhaust. The engine simply refused to start twice or thrice. I again tried to crank after 5 minutes and the engine started without any issue. But this time the engine check light has turned on. I called up Advaith Hyundai Service and my SA asked me to get the car for inspection on Thrusday as he is on leave for three days.

I searched this forum for similar problem and could see many engine misfire threads matching the description of my issue. I have serived the car on regular intervals. The first three free services and the first paid service has been done. Could this be the problem of engine misfiring or is it some other issue?

I have also been observing from the past one week that during cold starts, the hum of the engine is not constant i.e, it fluctuates a bit like a sine wave. After one or two minutes it used to be normal.

Edit: I couldn't notice any changes in the fuel efficiency. Will keep a tab on this.

Regards,
Vinay

[nettooran]

Hi

Please check the following link and see if it is useful for you.

http://www.carwale.com/forums/viewthread-25959.html

Raj

[Jaggu]

Get it checked the loud sound is not a good thing in Diesel engines, the link above talks about petrol car.

My suspicion is something to do with fueling, can be bad quality fuel with water in it OR fuel rail issue. Anyways get it checked asap. Since this happens overnight take the car in the evening and ask the service guys to check in the morning.

[guyfrmblr]

Originally Posted by Jaggu

My suspicion is something to do with fueling, can be bad quality fuel with water in it OR fuel rail issue. Anyways get it checked asap. Since this happens overnight take the car in the evening and ask the service guys to check in the morning.

I have been filling diesel from the same bunk from past one year and the quality of diesel was good.

I think its something to do with the fuel rail. There was a small hole in one of the tube going into the fuel injector around a month back. Small amount of liquid used to get sprayed in the engine bay due to this. I had reported this issue with Advaith Hyundai and they replaced the tube after which the leakage stopped. I had reported this in my ownership report post #57 (http://www.team-bhp.com/forum/test-d...-report-4.html).

[GTO]

I remember you had some pretty serious underbody work done (link to thread). I'm hoping that the two incidents aren't related (poor reinstallation etc.)

[Jaggu]

Yes from what you explained its indeed a fuelling issue, misfire and associated smoke. New Crdi engines are very sensitive and very expensive to repair hence a good idea to get it checked asap.

[guyfrmblr]

I tried cranking the engine this evening and didn't face the issue. But the check engine light was continously glowing.

Originally Posted by GTO

I remember you had some pretty serious underbody work done (link to thread). I'm hoping that the two incidents aren't related (poor reinstallation etc.)

Its exactly an year since my car took that nasty under body hit. It may be due to the poor re-installation as you mentioned. Will get it thoroughly checked on Thursday.

[Mpower]

To me these symptoms are pointing to a CPS malfunction. (crank position sensor..or could be cam position).

The injection timing is completely messed up because of this and is causing the cracker sound (misfire) and the smoke.

The malfunction is intermitent and thats why it sometimes runs OK.

You should be seeing a check engine light no?

[guyfrmblr]

Originally Posted by Mpower

To me these symptoms are pointing to a CPS malfunction. (crank position sensor..or could be cam position).

The injection timing is completely messed up because of this and is causing the cracker sound (misfire) and the smoke.

The malfunction is intermitent and thats why it sometimes runs OK.

You should be seeing a check engine light no?

Yes. The check engine light is ON. The misfire is intermitent as you rightly pointed out. It happened only twice. I tried to crank the engine this morning and din't notice any misfire. Does the ECU scanner gives out the error code which points out to the exact issue?

[Mpower]

Originally Posted by guyfrmblr

Yes. The check engine light is ON. The misfire is intermitent as you rightly pointed out. It happened only twice. I tried to crank the engine this morning and din't notice any misfire. Does the ECU scanner gives out the error code which points out to the exact issue?

Yes, the scan tool will give out an error code which tells you exactly which sensor is the culprit.

[SS-Traveller]

Originally Posted by guyfrmblr

...could hear loud noise from the engine. The sound was like fire cracker bursts. I could also see a thick cloud of smoke from the exhaust.
...during cold starts, the hum of the engine is not constant i.e, it fluctuates a bit like a sine wave. After one or two minutes it used to be normal.

And you did not have the check engine light on when this was happening? The CEL only came on afterwards?

[guyfrmblr]

Originally Posted by SS-Traveller

And you did not have the check engine light on when this was happening? The CEL only came on afterwards?

The check engine light came up only after the first misfire.

[SS-Traveller]

Originally Posted by guyfrmblr

The check engine light came up only after the first misfire.

A few quick questions:
Did you have an engine decarb done recently?
Did you add anything to the diesel/engine oil recently?
When you accelerate hard in each gear, do you get smoke from the tailpipe?
Does the check engine light go off once the engine is warmed up?

[guyfrmblr]

Originally Posted by SS-Traveller

Did you have an engine decarb done recently?

No

Did you add anything to the diesel/engine oil recently?

No. I have got the engine oil replaced by Hyundai A.S.S every time.

When you accelerate hard in each gear, do you get smoke from the tailpipe?

I have noticed sometimes in 1st, 2nd and 3rd gear under hard acceleration. But is it not a common phenomenon in diesel cars?

Does the check engine light go off once the engine is warmed up?

The CEL doesn't go off.

[csateesh]

The symptoms clearly highlight only the following

1. Timing issues - Improper firing will lead to this which is due to timing
2. Fueling issue

Like everyone else says primary suspect is #1