[Fireguinness]

Hello fellow i30 owners. I have a problem I can’t seem to resolve with my car infrequently coughing, particularly in lower gears. I’ve replaced the fuel filter, all glow plugs plugs, a new set of injectors and now even my local Hyundai dealers are stumped - any ideas?

[eye30]

Have you had the car from new or just recently acquired it?

I ask as if just recently acquired, wonder if a problem prior to your ownership.

Have they checked ecu correctly set up with latest updates?

Re fuel filter...... has the fuel been possibly  contaminated

[Dazzler]

  Fireguinness,

Just out of interest what year and mileage. Not that that will make much difference in this instance, but always nice to have that info. Yes, those three things would certainly be the three most obvious. If it were a petrol I would have suggested the ignition plug leads next, but don't think a diesel has anything like that.

Been an expensive wild goose chase for you so far! With labour I'm guessing you are way more than a 1000 euros out of pocket already! 

[mickd]

Hello fellow i30 owners. I have a problem I can’t seem to resolve with my car infrequently coughing, particularly in lower gears. I’ve replaced the fuel filter, all glow plugs plugs, a new set of injectors and now even my local Hyundai dealers are stumped - any ideas?

G'Day fireguinness,

 

Just a thought,  have the dealer mechanics experienced the coughing or are they going on what you tell them?  By coughing do you mean you can feel and hear it ?
There was a couple of posts  the recently that complained about surging , running rough  and / or no grunt down low.  One cause was too low a speed in the particular gear and I  can't remember the other.
Someone will be along soon enough though .

[Fireguinness]

Hi, and many  Thanks for taking time to reply - I have actually wondered that myself funny enough as it does seem to happen in 2nd or 3rd gear around the town but recently it’s happened at full speed in 6th on the motorway so kinda blew the theory. By cough I’m describing the feeling as if you suddenly released the throttle and then straight back on full , the kinda jump you would experience is what I’m getting . A suggestion put to me today was an intermittent fault on the fuel pump which is expensive to replace if Its not the problem. Thanks anyway 😄

[nzenigma]

Hi mate,
Dazz has mentioned this, what model, mileage etc.??
Glow plugs do not operate when the motor is hot, so $$$ wasted.

"suggestion put to me today was an intermittent fault on the fuel pump..expensive ".   Big Call  Who was this? 

As a rule of thumb, Mechanical devices usually demonstrate failure by noise or poor performance then stop working! What you describe is more symptomatic of an electrical fault, it is like a switch being turned off...eg. sudden immediate stoppage.  Or in your case, off and on again.

In Britain, going from hot tepid weather conditions to freezing can occasionally cause electrical connectors to be unreliable. So while the engine idling physically move wires and see if there is a change.

I'm not sure if your "cough" is total power loss or partial. ??? If the latter, trace the vacuum lines, a solenoid may be causing your problem.