[MrWB]

Okay, so I wondered if anyone could offer any ideas (though I will be taking my car in to be looked at).

It's a 2014 plate, and I've had it from April 2015. Overall I haven't had any issues whatsoever, and keep fluids / oils / brakes / tyres in good condition. I had the front brakes replaced after the 3 year service (although they had a little bit of life in them) and the tyres replaced whilst they still had plenty of wear for a higher tread sport tyre (more grip, more tread = safer).

On about three occasions previously, I've had a loss of power when I've got to move off in 1st. Normally after the car has been running for a while. I say loss of power, it was like the clutch wasn't properly engaged, and required putting into neutral, turning off the engine and restarting to get going again. When it happens, and before the restart car just doesn't move more than about half a mile an hour, if that, whether you press the accelerator - whether gently and slowly or otherwise.

After the first time it happened, I thought it must've been me. Maybe I was in third? Maybe I wasn't in gear properly? It all happened pretty quickly, but I thought driver error.

The second time it happened was probably the best part of a year later, and I was definitely in first, and I was definitely in gear properly. I even moved to neutral and back again before restarting the engine, just to make sure - same problem.

The third time was about six months or more later than the second, and the same issue.

The thing is, once it's happened it runs absolutely fine and nothing has been able to be found wrong with it.

The other issue that occurred a few months back was that pressing the brake felt like there was a huge lump there. No other way to describe it. A hard block that stops the travel of the brake pedal right at the start of braking. Come off the brake, and press it again and it worked. Again, no issue afterwards and nothing could be found wrong. It didn't feel like ABS at all.

Today, though, I've had both issues at once. Afterwards the steering wasn't working accurately, and the brakes didn't come back properly. The pedal could be pressed, but it wasn't braking the car, and the power didn't come back - the car would not engage properly at all.

Got the other half (10+ years extra driving to myself) to give it a drive too as there had been a bit of ice (I know how to drive in ice & snow, and I was confident that it wasn't just ABS / loss of traction - but wanted a second opinion) - they agreed, and luckily this happened at the end of our street, and so we were able to get it back to almost outside the house. Even then, it required using the handbrake as the normal brakes just weren't working.

Called out the AA, and they turned up about an hour later. Explained everything, he gave the car a drive around the block, and it was absolutely fine. Checked and nothing was behind the servo, fluids all good, brakes in perfect working order, wheels & tyres good. He couldn't explain it beyond thinking I was a bit mad and it was probably just ABS & loss of traction --- but it really wasn't.

I'm going to get it looked at but I'm starting to lose trust in the car (only until the issues are identified and sorted) - if what happened today happened on a dual carriageway or motorway at speed, it could be a nasty accident.

The thing is, if no issue can be identified except right at the moment when these things happen, how can I get them sorted?

[Dazzler]

When I first saw your long post I thought 

But once I read it, I can understand and appreciate the detail required.

These are very scary faults and as you suggest, extremely dangerous in the wrong situation. I appreciate you not going into a rant, like many people would.

Hopefulky this time the car has thrown some error codes. To be honest, without being a drama queen (referring to me) I would request a loaner and refuse to accept the car back until it is sorted under warranty. I hope the dealer and Hyundai are supportive.

I guess it has to be either an intermittent fault in the BCM/ECU or some sort of short in the wiring harness?

I assume you are in the UK, looking at your model designation. Having at least the country in your profile can be helpful in these situations at times.

[MrWB]

Thanks, @Dazzler, I appreciate the response and ideas.

I am in the UK, I'll go and update my profile after posting this.

There's no point in going into a rant, won't solve the problem and in fairness the i30 overall is fantastic. Any car can have problems - they're mechanical and electrical beasts with more and more coding added. I just need to have it identified and fixed, more for safety than anything else.

I've dropped the car across to a family friend that owns his own garage to take a quick look as he's 7 miles away, opposed to 45 miles to the dealer. The family friend generally does all the inlaws and other half's car work, and if this wasn't such a newish car still under warranty and me wanting to get the service stamps from the dealer to help keep value, he'd be doing everything on the i30 too.

But thought it's better to travel a shorter difference and let a different set of eyes take a look too. He's gonna get it hooked up to the computer there to see what he can see as well.

Just didn't feel comfortable taking it 45 miles on National Speed Limit roads when there's a much closer alternative with a more than trusted friend.

[eye30]

Well if he id's a warranty or part failure fault then put the car on the road and call the dealer asking them to recover the car.

Probably ask you to call the designated recovery company which i think is the AA.

[MrWB]

Awesome, thanks @eye30! Appreciate the idea and it's definitely the way to go!

[MrWB]

Quick update.... The garage have looked over everything they possibly can, tried to replicate tests and issues on their rolling road, tried multiple different computers, checked with an external subscription service to see if anyone else has reported similar issues with i30s before.... They can't find anything wrong whatsoever.

Guess it's off to the dealer then... But if nothing's showing as wrong and everything's exactly as it should be, it's slightly concerning!

[Dazzler]

Quick update.... The garage have looked over everything they possibly can, tried to replicate tests and issues on their rolling road, tried multiple different computers, checked with an external subscription service to see if anyone else has reported similar issues with i30s before.... They can't find anything wrong whatsoever.

Guess it's off to the dealer then... But if nothing's showing as wrong and everything's exactly as it should be, it's slightly concerning!

Thanks for the update. So frustrating and I think slightly might be understating it a bit.

I wish my wife had your temprement.

Makes me think even more that some wiring is being pinched or shorted somewhere. Certainly no a common occurrence.. 

[mickd]

G'Day MrWB,
Definitely odd.
Hard  brakes: I  would associate with no power assist from booster. No vacuum.
Won't accelerate : ???????
Next time it does it, put  hazards on , leave it where it is and have it towed back to dealer and ask for loaner car. May stuff your day but better than coaxing it anywhere.
You've just put on an open forum what it's doing and that it is  intermittent fault.
From insurance point of view "driving with known fault " - no cover.
Every time it does it, leave it, tow it -etc,etc, etc.k
Keep us posted   

[MrWB]

Hard  brakes: I  would associate with no power assist from booster. No vacuum.

That was the first thing our family friend thought of, but it's checked out as absolutely perfect.

Won't accelerate : ???????
Next time it does it, put  hazards on , leave it where it is and have it towed back to dealer and ask for loaner car. May stuff your day but better than coaxing it anywhere.

Yup, that's what the dealer have now said to do.

You've just put on an open forum what it's doing and that it is  intermittent fault.
From insurance point of view "driving with known fault " - no cover.

The only thing I can really say if I'm ever in that position (and I hope I'm not!) is that I've had it checked out professionally, and I've been told that there is nothing that can be found wrong with the car. Firstly by the AA, and then by a respected and successful local garage.

I've also spoken to the dealership who have given their advice (which is the same as yours - if it happens again, have it towed back to them) but unless the issue is presenting itself there's nothing that they would be able to do.

So if I wouldn't be insured in these circumstances that would mean that I'm paying for a car I'm not allowed to drive. The fact that I've had the car checked out and been given the all clear, surely that has to stand for something?

[Dazzler]

@MrWB

Don't sue me, but I believe you have done everything in your power to sort the issue. Your arguments appear sound to me. Hopefully in the worst case scenario the insurance would see it that way too..

[MrWB]

@MrWB

Don't sue me, but I believe you have done everything in your power to sort the issue. Your arguments appear sound to me. Hopefully in the worst case scenario the insurance would see it that way too..

I'm going to look into it some more, because insurance companies do like technical get-out clauses...! And I don't want to be in a position whereby I'm not insured.

However I think I've been responsible and taken the actions I should have, so don't know what else I can do unless it happens again?

[eye30]

To cover yourself get a written report from dealer.

[Dazzler]

To cover yourself get a written report from dealer.

Good idea. It might push them to give you a loan car until the problem is identified and sorted.

[mickd]

To cover yourself get a written report from dealer.

Excellent idea !, puts responsibility back to them.
Having dealings with insurance company at present so may be that's  why I'm a little bit negative / super wary .

[PhireSideZA]

Could your ABS system be fooling around? To me it appears as if your brakes are clamped tight to the discs, thus causing the lack of power?

And then perhaps the system releases and doesn't reengage thereby cutting stopping power to the wheels? I'd have a peek at the ABS system. Check for any leaks, loose wires, faulty hall sensors near the wheels, things like that.

Hope you find the solution pronto!

[Asterix]

I'm thinking Brake Switch failure.

It wont explain that "lump" you feel, but if the brake switch, by failure/internal short/whatever, is activated it will cut off power so you can only idle.

In the good old days you could apply the brakes while driving, but if you do that in a modern car it cuts off power immediately..