Hyundai i30 model 1600 cc Auto. diesel, now done 60,000 miles. About 10 months ago, I had difficulty starting the engine from cold.

The temperature would have been in the 50 to 60 degree Fahrenheit range.The glow plug lights came on several seconds before starting.

The car dealers said that the glow plugs required replacing, and this was done within the 5 year warranty, i.e. no charge.It seemed to cure the problem

Ten months later I am having a similar problem, the engine never starts first time. The outdoor temperature range would be about 40 to 50 degrees Fahrenheit.

Yesterday, it wouldn't start first time, the second time, I kept the starter on continuously for about 10 seconds, the engine turned over slowly and gradually gained momentum, and eventually started.

Once the engine is started, it starts up, first time during the rest of the day.

Does the car need new glow plugs again?


First of all thank you all for your comments, I have found them interesting to say the least. I tested the car's battery the other day, whilst the engine was not running, the voltage being 12.89 I have booked the car into the dealership in 3 weeks time. It will be left their overnight so they can check the engine form cold. I am not very confident that they will trace the fault.

I have forgotten to mention that about 6 months ago my son was driving the car home from his work, when suddenly the car's engine stopped, he managed to pull over to the side of the road. He then started the engine up, and it started. We have had no further incidents regarding this. Again I took it in to the car's Dealership, again they were unable to trace the fault.

I will take a copy of the answers you have given, and show them to the service manager. and see what he has to say. Thanks again.

  • It's very difficult to arbitrarily state causation and be correct. It could be low fuel pressure in your fuel rail. Do you have a check engine light or have you had the vehicle scanned for diagnostic codes? Many parts stores will scan your vehicle for free, you can then bring back to the troublecodes and modify your question. You will increase your chances of having good viable answers if you do this. Feb 9, 2016 at 4:41

3 Answers 3


Since the starter picked up speed as you cranked, I would suspect bad connections from the battery down to the starter. I have seen this before and simply disconnecting the large cable from the battery to the starter and cleaning the terminals with wire wool and reconnecting them totally changed the speed of the starter. Also clean the battery connectors, battery posts and the earth strap connectors from the battery to the vehicle body.

While performing this procedure make sure you disconnect the battery negative first and reconnect it last.


Glow plugs are not necessarily the problem. You said the engine turned over slowly. If turning was exceedingly slow then the battery would be more likely, not enough juice for the engine to gain momentum. If the engine turns over normally but just won't start, and when it does the start is "dirty", then the glow plugs are very likely. They aren't difficult to check, you can find the procedure in the answers of this question.

Other possible issues are a faulty high pressure fuel pump, a clogged fuel filter or clogged injectors, though these would probably show up every time you try to start the engine.


I had the same problem, I replaced the glow plugs, still the same problem, I then added Fuel injector cleaner and took the car for a run on the highway in 4 and 5 gear to clean out the injectors and problem solved. A diesel engine going slow around town will only foul the injectors causing hard starting and excessive smoke when it eventually fires.

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