[daveo70]

Hi all, my i30 2010 2.0 has an annoying intermittent problem where the engine seems to surge while driving.
Thought it was transmission issue but just serviced and issue remains.
Service and auto service just done not rectifying issue.
My mechanic seems at a loss.
Any ideas would be greatly appreciated.

[CraigB]

Petrol or diesel? is it like a running out of fuel surge when was fuel filter last replaced? does it only surge while driving or is it evident when stationary and free revving the vehicle as well?

[tw2005]

Petrol or diesel? is it like a running out of fuel surge when was fuel filter last replaced? does it only surge while driving or is it evident when stationary and free revving the vehicle as well?

2.0 = petrol

Same question as Craig regarding when, can you be more descriptive.

Can you feel the difference between torque convertor lockup and release? Anything like that? In my diesel often it's locked up and as you go up a hill it will release and RPM increases for same road speed.

[CraigB]

2.0 = petrol

I thought it likely was petrol but isn't there a 2ltr diesel in the FD range

[tw2005]

2.0 = petrol

I thought it likely was petrol but isn't there a 2ltr diesel in the FD range

Europe yes, Australia  no. It may have been fitted to Sonata here , old SOHC design I think

[CraigB]

2.0 = petrol

I thought it likely was petrol but isn't there a 2ltr diesel in the FD range

Europe yes, Australia  no. It may have been fitted to Sonata here , old SOHC design I think

Thanks for that, I'll lock that info in the databank

[daveo70]

it feels like revving/surging at approx.60/70kph when changing gears but auto just serviced and no issues there.
It is slightly better after auto service though.

[tw2005]

it feels like revving/surging at approx.60/70kph when changing gears but auto just serviced and no issues there.
It is slightly better after auto service though.

Right, so would it be accurate to call it shift flare?

Slightly better after trans service and happens in between shifts,  that would make me think transmission related.

Who checked the box out? mechanic or trans specialist?

[tw2005]

May be worth trying to capture a video of the instrument cluster so we can see speed and RPM, hopefully audio and watch the dials on the shift

[daveo70]

it was auto specialist
will try and video when able,
thanks so far gang much appreciated

[Shambles]

will try and video when able,

Please be very careful when videoing while driving

[Dazzler]

Hi Dave, Sorry to hear about your troubles.

Like Gerard says I would still put money on it being the transmission. That 4 speed box plays up quite a bit in the 2010/11 diesels (not so much in the petrol versions) but the symptoms sound more trans than engine related unfortunately.   

[tw2005]

shift flare is generally pretty obvious. If you are driving normally  say with moderate acceleration and the box goes to shift from one gear to the next and at that point the motor rpm flares up on the shift point momentarily then dips then it's in the box.

I've had it in Mits boxes from a pressure loss internal and also after a box swapout or computer reset because the adaptive software adjusts as the box wears but in the latter case it corrected itself through driving.

[nzenigma]

I too punt for a transmission fault.
Dave does not mention RPM increase, or hasn't noticed  ,, yet ?????
An improvement after auto service (was it only auto not motor ????)
Again that points to transmission fault.

Could be our old friend, the valve body. 

[daveo70]

Revving, Rpm jumps when moderately accelerating.
Have had issue for a while through services,
After recent general service still same
After first Auto service only very slight improvement
Both services done in last 2 weeks
Neither have picked up any issues though.

[nzenigma]

I think you need to find a good mechanic who has some experience. Not these yo-yos
I may be wrong but this sounds like the valve body.
Irrespective, if you can detect the flare, why couldn't your trans. expert?
 Does 'couldn't pick up issues' mean they did not test drive, did not see physical evidence or just dont know how to fix it?
The valve body replacement can be done with trans in car. Even DIY 

Find someone like this for 2nd opinion.
  Hyundai i30 soft, harsh & flaring gear shifts 4 speed automatic ? Col Voss

[daveo70]

This is best lead I’ve had yet wish they’re in Melbourne
Thanks

[tw2005]

If it is the valve body here's another bit of info few are likely aware of. The VB in the i30 4 speed is the same across the 4 speed boxes including late model i20.

So let's say you needed one ,you could take a punt for $300 and get a 60000k unit from a 2015 i20 transmission from Tasmania

Valve body can be swapped out with the transmission in.

Otherwise about a grand genuine ordered from Korea landed or buy a new car if you go through a dealer.

I flush my trans out 3 years or 60000K. I've used Mits SP3 from the dealer as it's cheapest and also used penrite multivehicle FS.

Just purchased 20L drum ready to do again on one of mine.

[daveo70]

Hi again,

Just had car at Hyundai for their opinion,
they're also guessing valve body but have steered me to their preferred auto specialist.
Will let you know how i go.
Not at all car savvy so thanks again for your thoughts and advice.

[nzenigma]

  Well done Hyundai dealer. Good PR.