Car losing power after reaching around 3000rpms

MrBrindle

Good evening,

Having a problem with our Hyundai ix35 2011 plate.

Back in February when we had that cold snap, it began to lose power when accelerating, usually around 3000rpms. The engine didn't cut off, but would just lose power and the car would slow down. After 10 seconds or so, it would kick back in and drive as normal. Shifting down gears didn't help with the acceleration either. It seemed to happen at random, but mainly in the mornings.

Got the local garage to check it out, as an engine light did come on and off. They plugged it in to run a diagnostic, but didn't find any faults. I think they may have cleaned a filter perhaps, but I can't remember exactly what filter. Anyway, it stopped doing it, and has been running fine all year until this week when the weather has gotten colder again.

It's a diesel car, and my partner usually does short journeys with it (school runs etc), and a daily 8mile stretch on a dual carriage way.

Any idea what could cause this? Like I said, I cannot remember what my local garage did, and we have moved away from that area now.

I'm just a bit perplexed how it's been fine for nearly 8 months, and the same issue has just appeared again. Strange.

Thanks all.

wgl2014

I would suggest running a decent concentrated fuel system cleaner through. Diesel engines can be sensitive to relatively small deposits that build up over time.

I know people's opinions vary on these and many think they are snake oil but I have had positive experiences in the past.

I wonder if the shift to winter diesel is having an effect on the cars fuelling?

facade

If it were petrol, I'd suggest a blocked catalyst, so maybe the DPF is blocked up?

neilmcl

Sounds like a DPF issue to me. Your garage probably performed a forced regen on it to clean it. Modern diesel cars and regular short journeys don't mix.

AdrianC

Modern diesel, short runs and low use.

Place bets.


<10 minutes bimbling along a dual carriageway won't get it anywhere near warm enough - especially in low ambients - to start a regen.

MrBrindle

AdrianC wrote: »

Modern diesel, short runs and low use.

Place bets.


<10 minutes bimbling along a dual carriageway won't get it anywhere near warm enough - especially in low ambients - to start a regen.

So it's most likely a blocked up DPF again?

We are thinking of changing to a petrol due to the type of use it gets.

Lorian

Assuming it hasn't been done for some time the first thing I would do is replace the diesel fuel filter. It can cause this symptom on the U2 Diesel Engine.

Waxing in the filter has been an issue on some IX35 (1.7Crdi) in the cold too (google) I think they might have designed a new filter housing to fix the issue, but unless there was a TSB for it that never got done in the warranty period your likely to have to pay £££

MrBrindle

Lorian wrote: »

Assuming it hasn't been done for some time the first thing I would do is replace the diesel fuel filter. It can cause this symptom on the U2 Diesel Engine.

Waxing in the filter has been an issue on some IX35 (1.7Crdi) in the cold too (google) I think they might have designed a new filter housing to fix the issue, but unless there was a TSB for it that never got done in the warranty period your likely to have to pay £££

Yeah, I've just read a lot of articles/forums online about the filter and waxing problem. Looking back on the service history, fuel filter was replaced around 4 years ago. But I assume the garage we bought from would have replaced it before selling when we bought it two years ago.

I actually rang a Hyundai dealer this morning to ask about this and was surprised that the bloke had never even heard of an issue with it, even though Watchdog investigated it, and there's plenty of documentation online about the problem.

Saw this on another forum: 'They even said their service guys who drive ix35's carry spare filters around with them in the glove compartment in case they go. Hardly a ringing endorsement for the car!!'

Will be trading this in when it's fixed!!

MrBrindle

Hi all, booked in our local garage for tomorrow, however they don't do dpf cleaning :-( I have advised that theres a lot of stuff online about the fuel filter, so maybe be worth looking to replace that.

Our local Hyundai dealer is 30mins away, which is a pain.

Regarding the dpf regen, prior to this problem I did notice that the car's mpg average had dropped to 30mpg from its usual 42-45mpg. It's come back up to the usual mpg now. Was that low mpg a sign that dpf regen was taking place?

Slightly off topic, and it might be just me having a bit of car worry now, but recently I've been turning our other car on in the mornings to warm up, and noticed that for the first 10-20 seconds after starting it the exhaust fumes stinks (outside not inside). The car is a diesel 2009 peugeot. It was serviced 3 months ago, new oil, filters etc, so not sure why it would be smelling that bad. Or is this expected from a car of that age? After the initial 10-20 seconds the fumes smell returns to normal.

DoaM

MrBrindle wrote: »

Our local Hyundai dealer is 30mins away, which is a pain.

Maybe a drive there and back might be good for your car?

MrBrindle

DoaM wrote: »

Maybe a drive there and back might be good for your car?

Haha, yeah I know. I've read of conflicting info online regarding the regen. Some people/articles mention a swift drive at 70mph does the trick, others say you need a good 30-45mins of solid 50mph+ driving. What is correct?

The bloke at the dealership did suggest we take it for a 45min to 1hr drive as a mean of flushing the dpf and egr valve. So we did attempt it, but it was losing power so often it just felt dangerous doing so. Especially with so many hills around where we live.