Garmaine Staff asked 3 years ago

I have an Audi A5 1.8 TFSI Sportback from 2011, bought it recently (4 months ago), which ran fine until two weeks ago. The engine went through diagnosis and the operator showed a broken spark plug to me.

The electrode broke off inside the engine (see image below).

spark plug electrode

The question is: does the electrode (circled in the image) break off? Does it break off when the engine runs too hot?

To answer the question, you should know that there's another defect with the Audi: four weeks ago I noticed that I'm frequently running out of engine coolant. I checked it at a mechanic and they found, that the water pump was leaking. I was unable to afford getting a new one. They said I could wait a couple of weeks with that, specially because it's currently very cold (+5°C outside) and I would have to fill coolant liquid myself until then – which I did.

Could that have been the cause? Because I was low on coolant, the engine went too hot and the spark plug electrode broke off?

Secondly I have another (legal) question which might suits here (or not, please correct me): Do (by germanys legal warranty) I have to pay for this or the dealer?

Here's some facts:

  • Date of purchase: 16.09.2019
  • Date of first registration: 16.08.2011
  • Date of incident: 17.01.2020
  • Car was on 88.000 km when I bought it, now is on 98.000 km
  • Chequebook says, that spark plugs have never been exchanged
  • Chequebook says, that I have to exchange spark plugs for my model every 90.000 km or 6 years

I dropped the car off at the car dealer and went for legal warranty. He now claims, that the spark plug wasn't the issue – instead the engine went to hot.

Is he right? My temperature gauge showed no more than the usual 90°C as always. I was pretty low on coolant fluid (like 30-40%).

The other thing is… Can I claim, that he sold a faulty car because the spark plugs were past lifetime? All of this might now have happened when I fixed my waterpump – but I'm not sure if it's actually my fault or the dealers fault.