So an update!!

I reinstalled the firmware on the head unit following ALL the instructions and fingers crossed its all working perfectly so far.

I don't want to get my hopes up too much but its seems to be all good.

will properly test it in the next few days and update this thread.

Regards,
Lophophoria

Have you had fuel pump tested to make sure pressure ok

As with my last reply, I actually have no idea (I know ..I'm rubbish at remembering this sort of stuff!), but I'll mention to my mechanic. Thanks for the suggestion

Regassing your aircon won't help your problem. I was just looking for a correlation.
Have you used a code reader to see if some fault condition has been reported by the ECU?
I'm guessing not by your question. An On Board Diagnostic (OBD) bluetooth reader is cheap and easy to use.

Have a simple code reader I used...no codes came up

Bob W.

I have thought about trading it in but I want to investigate my options first. I could not sell it privately and sleep at night.  No smoke!  Apparently modern synthetic oils and the CAT are stopping exhaust smoke.

Terry T
Thanks for your thoughts.

Answers..
1  Yes
2  No
3  No
4  No - see above
5,6,7,8 and 9 are on the agenda.  The car is booked into my local trusted mechanic in a couple of weeks.
PCV will be the first thing checked.  I considered taking of the rocker cover and  checking the PCV myself but I do not have the equipment to do the other tests so, I will leave it all to them.  I will post again if anything comes to light.

URL for class action and a summary follow.

Hyundai Engine Class Action – Register Now

Overview
On 15 February 2023, class action proceedings were commenced against Hyundai (the Australian entity, Hyundai Motor Company Australia Pty Limited, and its South Korean parent, Hyundai Motor Company) in the Federal Court of Australia in relation to defective engines in various Hyundai vehicles sold in Australia from 2011 to date. 

The proceedings are action no. NSD 131 of 2023 in the Federal Court of Australia.  ‍

The action is being funded by Woodsford, a leading global ESG, access to justice and litigation finance business. The applicant is represented by law firm Johnson Winter Slattery.

A separate but similar proceeding has also been commenced against Kia.

Cheers
Michael

‍

Do you have a multimeter or at least a lamp-based probe?