[jbh500]

Hi everyone, been an avid reader of the forum for a while but only just registered! I have a 2010 1.6 CRDi 115PS CW with 5400 miles on the clock. I have owned the car from new. When I bought the car I was so impressed by how refined the diesel engine was - the most un-diesel like diesel I had ever driven! After 5400 miles though I have a bit of a problem that came on suddenly. The engine now has a harsher tone to it, especially around 1500 RPM and when I pull away under load in 2nd or 3rd gear from around 1200 RPM there is a loud knocking sound (like pinking in a petrol car only louder) until the engine gets to around 2000 RPM. It sounds like fuel detonation at the wrong time and seems worse when the engine is hot. Even my wife noticed the difference in sound when she drove the car and she is not very mechanically minded - she said it sounded much louder, like an old style diesel! The car runs ok besides this and the fuel economy hasn't changed. I have checked the oil and water and they are fine. I have got the car booked in with Hyundai next week but I was interested to see if anyone else had seen this problem so I could be armed with more information when the car goes in! Thanks in advance to anyone who takes the time to reply!

[asathorny]

I don't have a diesel myself, but the other members who have sing there praises constantly, I am sure some of them will be along anytime soon to chat with you bout this....  you've done the right thing so far, dealership visit 

[Dazzler]

Welcome jbh,

We did 68000 kilometres in our previous 2008 Diesel Hatch without a hiccup..

Not a common symptom although original U series Diesel Motor (as against the later U2 version) didn't like being under load in higher gears under 1500 Rpm ..

You could disconnect the battery for half an hour or so to reset the ECU to see if that makes a difference (if you do the Stability Control Light will take a time to reset as well)

[Doggie 1]

I have nothing really to add as I haven't had these issues either but hope it's resolved satisfactorily.
Mine is the origin U too.

[rustynutz]

Not a common symptom although original U series Diesel Motor (as against the later U2 version) didn't like being under load in higher gears under 1500 Rpm ..

You could disconnect the battery for half an hour or so to reset the ECU to see if that makes a difference (if you do the Stability Control Light will take a time to reset as well)

 

[Phil №❶]

Hi jbh500 & welcome aboard,

As an avid reader of the forum topics you will know that this is not a common problem. I suggest a few more revs before changing gear. The dealer should be able to sort any problems. Maybe suggest an early oil change too, to be on the safe side. Let us know how you fare. 

[jbh500]

Hi guys, thanks for the quick replies! Looks like this isn't a common issue but I think I will give the ECU reset a try today and let you know how that goes!

[jbh500]

Hello again, I disconnected the battery for about 45 minutes yesterday to reset the ECU as suggested. The ESP OFF light stayed on for a while afterwards just as stated! I have done around 5 miles but the car doesn't seem any better, if anything slightly worse. It may take a few more miles to "re-learn" the settings maybe? I have got a few trips to do over the next few days so I will see if anything changes! Booked in at my local Hyundai dealer on Thursday!

[Dazzler]

Shame that didn't work. But it is one possibility you can now tick off. Hope it gets sorted Thursday 

[Shambles]

Timing chain tensioner is the next thing that springs to mind, but good call on the ECU reset

[neoto]

jbh500, do you have DPF in your car?

[jbh500]

Hi, no my car does not have a DPF!

[jbh500]

Hi, just got back from local Hyundai dealer. The first thing they did was to come out with me in the car so that I could demonstrate the sound. Once I had demonstrated the engine sound to the technician he said that it was "diesel knock". He said that there didn't appear to be a problem with the engine as such and that the system is very closely monitored by the ECU which would throw up a warning light if there was a real problem. The first thing they want to rule out is the fuel quality. The current tank of fuel is supermarket stuff and the technician said that until they could rule out poor fuel there was not a lot else they could do. They have asked me to run the tank low and then fill up with quality fuel such as Shell or BP. Once that fuel has had chance to get through the system they want me to let them know if the problem has been solved or not, if not then to book the car back in! It will probably take me a couple of weeks to run the tank low and refuel so I will report back after that!

[eye30]

The first thing they want to rule out is the fuel quality. The current tank of fuel is supermarket stuff and the technician said that until they could rule out poor fuel there was not a lot else they could do. They have asked me to run the tank low and then fill up with quality fuel such as Shell or BP.

Interesting...............

When I had my diesel I always used Shell and had no trouble.

On the odd occasion I used Tesco's fuel, after getting a money off voucher, I did notice a change in how the car performed but returned to its old self once I refilled with Shell..

[Dazzler]

Seems a bit of an odd one... It's "diesel knock" but ... I guess time will tell.

[xdrew]

I confirm this observation. At some moment, my 90hp CRDI started to produce 'metallic detonation' 'old-diesel style' sound at 1500-1900 RPM when accelerating. I was driving mostly urban-style in last month, no motorway trips. I did not care so much, but today I
- filled the tank at another station
- did a 200km trip on motorway, 130-140kmph @ 2500+ RPM.
-> the metallic sound went away! Now it has that normal 'velvet', low sound even at lower ~1000 RPM.
So, my first conclusions -
either my previous fuel supplier sucks
or having DPF non-regenerated for a long time makes ECU to control the engine in a non-optimal way.

BTW, my friend with 1.5 dci Nissan complained on the same symptoms. I think he gets gasoline on the same (presumably wrong) station. I'll advice him to change, just to see how this helps.

[Phil №❶]

It would appear that fuel can be a contributing factor to unexplained engine anomalies. I suggest people with any apparent engine malfunctions try a different fuel supplier, it may save a lot of time and headaches looking for something mechanical / electrical that's not even there.

[AlanHo]

It would appear that fuel can be a contributing factor to unexplained engine anomalies. I suggest people with any apparent engine malfunctions try a different fuel supplier, it may save a lot of time and headaches looking for something mechanical / electrical that's not even there.

A possible problem with that suggestion is that someone may continue to run the car for several hundred km to use up the old fuel when they actually have a mechanical problem that then causes more damage. Maybe OK if you are still in warranty - but could be expensive if not.

[Dazzler]

Very good point Alan...

[i30sean]

I only use Shell in my Crdi unless Im away and need to fill up. However, occasionally my wife uses my car and will fill it up with Tesco's Diesel and I see a drop in MPG and the car isn't as responsive.

i30Sean

[jbh500]

Hi everyone, sorry for the long time between posts but I wanted to make sure that I posted up a worthwhile response! Thanks for the replies in between! After the visit to Hyundai I let the tank get low until the fuel warning light came on and then filled up with Shell diesel. I then went on a 120 mile motorway round trip and have since been running around for a few more days. On the 120 mile motorway trip the car performed really well and averaged around 50 MPG. I have to say that there has been no difference in the noises and symptoms at all so far! I am going to run a bit more with the new fuel and if there is no improvement then its back to Hyundai! I'll keep posting updates when I have anything new to tell!

[Doggie 1]

I hope it's sorted to your satisfaction.
I guess I'm lucky because I quite like the diesel sound in an engine but I can't say that it's been excessive in my car.

[Dazzler]

Still doesn't sound right to me.. if you know what I mean 

[Phil №❶]

someone may continue to run the car for several hundred km to use up the old fuel when they actually have a mechanical problem that then causes more damage. Maybe OK if you are still in warranty - but could be expensive if not.

I hope Alan's not foretelling the future 

[Doggie 1]

I think he might have been a fortune teller in his earlier life   

[agentr31]

good old fashioned 'labouring the engine' its a tiny engine, your driving it like its a 6-71!! keep it above 1500 rpm and it will be happy, they do perform very well to 3500 rpm!!

[jbh500]

Hi, I don't think it's the way I drive it because it has been perfect up to 5400 miles and then suddenly things changed. I have driven another i30 with the same engine for 10 days and that behaved perfectly as well! I didn't drive that any differently! With regards to keeping it above 1500 RPM thats not always possible. Sometimes you slow down for a junction in 2nd gear, have a look and then pull away from a slow speed without actually stopping. The car has never been bothered by this before but now if I do this it makes the diesel knock sound quite badly as it pulls through 1500 rpm up to around 2000 rpm then is quietens down. It has also started making the horrible diesel knock sound in 1st gear as I accelarate away from standstill. The engine now just feels harsher and not as smooth. Things don't seem to be improving with Shell fuel so I will probably be booking it back in with Hyundai soon!

[eye30]

Could it be the Tappets need to be checked and adjusted?

Or even

an injector is defective?

[jbh500]

Hi, yes I'm thinking a defective injector could be the problem too! I wonder how keen Hyundai will be to start replacing injectors 

[Dazzler]

I feel for you jbh  These type of faulty are a pain if the Dealer drags their feet finding it ...