Hyundai i20 knocking/tapping like engine sound in 4th/5th gear

[Wakandafication]

Hi all,

2010 model with 166 000 on the clock, has been serviced at Hyundai it's whole life. Vehicle is in CPT central and serviced at Hyundai Paarden Eiland the last few times.

Hyundai can't find the issue, and possibly because it only happens in 4th/5th gear when the engine is under high load with low RPM which is difficult to reproduce. They suggested lifters, but I'm not convinced.

When driving on a flat road there is no issue, then approaching an incline the car slows down and doesn't have enough torque, so before shifting down a gear this sound can be heard. I assume there is increased load on the engine during this period. It only happens (I think) in the 4th/5th gear in such instances going up a hill. What could it be as it's time consuming going to places only to be told there's no sound or to misdiagnose the issue like lifters when it might be rod knock? Is there a common issue with this type of car which others have experienced?

Here's a sound file, you can faintly here it in the beginning: https://vocaroo.com/11w6wzsg1qxe

Thanks,

 

[Gnome]

Hi all,

2010 model with 166 000 on the clock, has been serviced at Hyundai it's whole life. Vehicle is in CPT central and serviced at Hyundai Paarden Eiland the last few times.

Hyundai can't find the issue, and possibly because it only happens in 4th/5th gear when the engine is under high load with low RPM which is difficult to reproduce. They suggested lifters, but I'm not convinced.

When driving on a flat road there is no issue, then approaching an incline the car slows down and doesn't have enough torque, so before shifting down a gear this sound can be heard. I assume there is increased load on the engine during this period. It only happens (I think) in the 4th/5th gear in such instances going up a hill. What could it be as it's time consuming going to places only to be told there's no sound or to misdiagnose the issue like lifters when it might be rod knock? Is there a common issue with this type of car which others have experienced?

Here's a sound file, you can faintly here it in the beginning: https://vocaroo.com/11w6wzsg1qxe

Thanks,

Sounds like engine knocking but it is impossible to tell because there is no subjective way to tell how loud it is. Is it load, or can you barely hear it with the radio off?

Rod knock is a bearing failure; meaning metal is literally being ground down. It doesn't come and go and it is loud and unpleasant. You wouldn't mistake that for "maybe something is wrong"

Lifter noise isn't something to be worried about.

Are you having some kind of problem or are you just worried? Did you just buy the car or something?

Overall my advice is to not open the engine, especially by the dealers unless you want real problems. The engine has knock sensor but it is running pretty high compression so it may be attempting to advance the spark but getting some knock then backing it off to the point where it happens just a little bit.

Hyundai engines are generally really reliable, until you open one up using a dealer that is. Lots of horror stories for dealers trying to fix the engines. And Hyundai Parden Island is a pretty useless bunch, I don't even trust them with oil changes anymore because they overfill and the sump nut is all stripped. So they can't even do that right.

 

[Ivan Leon]

Are you using the recommended fuel grade, as specified in the owner's manual? If it suggests a lower octane, such as 91 or 93 RON, try switching to 95 RON instead, and see if that reduces the 'knocking' sound under load.

Also, when were the oil, oil filter & fuel filter last changed?

 

[Gtx Gaming]

Are you using the recommended fuel grade, as specified in the owner's manual? If it suggests a lower octane, such as 91 or 93 RON, try switching to 95 RON instead, and see if that reduces the 'knocking' sound under load.

Also, when were the oil, oil filter & fuel filter last changed?

In Cape Town they only sell 95, we don't sell lower grade stuff here

 

[Sinbad]

Based on description of symptoms I'd say it's detonation. Check that correct spark plugs have been used (wrong heat range can cause this).

Also change down before the engine starts to labour.

 

[Wakandafication]

Sounds like engine knocking but it is impossible to tell because there is no subjective way to tell how loud it is. Is it load, or can you barely hear it with the radio off?

Rod knock is a bearing failure; meaning metal is literally being ground down. It doesn't come and go and it is loud and unpleasant. You wouldn't mistake that for "maybe something is wrong"

Lifter noise isn't something to be worried about.

Are you having some kind of problem or are you just worried? Did you just buy the car or something?

Overall my advice is to not open the engine, especially by the dealers unless you want real problems. The engine has knock sensor but it is running pretty high compression so it may be attempting to advance the spark but getting some knock then backing it off to the point where it happens just a little bit.

Hyundai engines are generally really reliable, until you open one up using a dealer that is. Lots of horror stories for dealers trying to fix the engines. And Hyundai Parden Island is a pretty useless bunch, I don't even trust them with oil changes anymore because they overfill and the sump nut is all stripped. So they can't even do that right.

Thank you all for the input.

The car was serviced regularly by the dealers, not sure what oil they actually put in. Car has been owned since new, with some accidents but all repaired via proper panelbeaters.

It's actually my wife's car so concerned it breaks phenomenally or breaks down while she's driving (being an essential worker and driving to undesirable locations for work).

It's not very loud, and almost sounds like a diesel engine not a metallic knocking/thumping - though I understand if this sounds ridiculous I can't describe it well.

I'll review the spark plugs and oil and not allow the dealers to open it. I appreciate everyone's feedback.

 

[WesleyDB]

When you say low rmp? What sort of rmp range are you talking about?

 

[Wakandafication]

When you say low rmp? What sort of rmp range are you talking about?

Like maybe 1800-2500 range.

 

[KhoisanX]

Hyundai can't find the issue, and possibly because it only happens in 4th/5th gear when the engine is under high load with low RPM which is difficult to reproduce. They suggested lifters, but I'm not convinced.

 

[Ivan Leon]

According to the official specifications, it appears that you are driving way too slowly in 4th or 5th gear at (1500 - 2500 rpm for the engine to be performing at its optimal peak torque performance delivery output, causing the engine to labour & for the 'knocking/tapping like engine sound' - which is called 'pinking' - to occur - Google this for a detailed description of its detrimental & potentially damaging (and expensive to repair) effect on your engine.

Change down to a lower gear, like 3rd gear, so that you are in a higher rev range, much closer to the optimal torque (pulling power) delivery figures, as detailed below.

1.2 litre 5MT engine specs


1/4 litre 5&6 MT specs


1.6 5MT specs


Link: https://www.autoevolution.com/cars/hyundai-i20-2009.html#aeng_hyundai-i20-2009-16-16v

As you can see from the above details, peak torque (pulling power) is delivered at 4,000 rpm for the 1.2 litre engine, and at 4,200 rpm for the 1.4 & 1.6 litre engines, so by driving at only 1,500 - 2,500 rpm in 4th or 5th gear, you are WAY below these figures, and you are straining the engine by trying to accelerate when climbing a hill in these gears at such a low rpm and thereby causing the engine to 'pink' under load - CHANGE DOWN TO 3rd GEAR and try climbing the same hill again at the same speed (or change down even further to 2nd gear if it is a very steep hill & you still lose momentum), and see if the noise has disappeared - if so, then you have solved the problem without even having to visit a workshop or spending any money to sort out a problem actually caused by an incorrect driving procedure.

 

[RedViking]

I listened to that recording.

All I hear if listen carefully is a breathy whisper

"I am coming for you. Run."