Warranty

RES2112

I purchased a new car in May 2025. It came with a full service and a 3 month warranty. 2 weeks ago, it broke down on the motorway. I had to call the AA and the mechanic that attended told me the spark plugs had disintegrated and the car was undrivable. I contacted the car dealership and they arranged for the car to be towed back to their mechanics, I then had to hire a car to get me and my family home. 
I have since had little contact from the car dealer, except to tell me that the car needs a new engine and as it is out of warranty I would have to pay for it. However the AA mechanic told me that the spark plugs should have been checked or changed when the car was serviced before I bought it.
Can anyone advise me on my rights please?

Keep_pedalling

How old and how many miles on the clock?

SiliconChip

2 weeks ago was within 3 months of any date in May so the warranty still holds, although whether it covers your issue will be down to what the warranty actually says.

Ayr_Rage

How old is this "new" car?

Make, model and mileage and price paid please.

Do you have evidence of what was carried out at the pre-delivery service and was it done by a franchised garage?

I've never heard of multiple spark plugs spontaneously disintegrating so either they were the wrong type or another catastrophic failure has occurred.

Has the car dealer confirmed the AA mechanic's diagnosis and do you have a written report from that AA mechanic?

Proving an existing fault at point of sale after it running for 3/4 months is not going to be easy.

eskbanker

Ayr_Rage said:

Proving an existing fault at point of sale after it running for 3/4 months is not going to be easy.

The burden of proof is reversed for the first six months, so it would be up to the dealer to prove that it wasn't present.

Ectophile

The warranty is only there to distract you from your consumer rights.

Within the first 6 months, any fault is deemed to have been present at the time the vehicle was sold, unless the seller can demonstrate otherwise.  On that basis, you have a claim against the seller.