Bought vehicle - engine knocking - Right to reject?

[Pugly]

Hi all,

Bought a vehicle, collected 19th November 2025, from an independent used car dealer 20 miles from home. Car came with a 3 month warranty through a 3rd party.

Noticed a rattling sound 13th December 2025, took the vehicle immediately to local trusted garage for a quick listen and to book it in for repair - suspected aux belt tensioner. Booked in for 17th December.

Vehicle was with the local garage 17th and 18th December, where they've found the engine is knocking - standing next to the sump with the vehicle running on a ramp it is clear the noise is internal.

Emailed the supplying dealer immediately (18th December) following the Which? template to state my intention to reject the car. Also attempted to ring them but no answer (10 mins before closing time).

Sent a paper copy via special delivery 19th December, which has arrived this morning (20th December) with proof of postage & delivery.

Also rang the garage who after a bit of back and forth have requested to see the vehicle on Monday 22nd December, with them collecting the vehicle from home.

I do not want them to attempt a repair and hand it back to me; I have made this clear each time I have spoken to them. I am wary of a sub-par repair being done on an already compromised engine.

They have not replied to any emails and seem reluctant to put anything in writing. I have been making a note of every interaction and also emailing them a summary of any phone calls that have taken place.

Is there anything else I should be doing to smooth along the process of getting my money back? I am concerned with the closeness to the 30 day right to return window - and the lateness of all the emails they are trying to kick it along beyond the 30 days and plead ignorance to receiving any emails.

Edited by Pugly on Saturday 20th December 13:24

[Alickadoo]

Pugly said:

Hi all,

Bought a vehicle, collected 19th November 2025, from an independent used car dealer 20 miles from home. Car came with a 3 month warranty through a 3rd party.

Noticed a rattling sound 13th December 2025, took the vehicle immediately to local trusted garage for a quick listen and to book it in for repair - suspected aux belt tensioner. Booked in for 17th December.

Vehicle was with the local garage 17th and 18th December, where they've found the engine is knocking - standing next to the sump with the vehicle running on a ramp it is clear the noise is internal.

Emailed the supplying dealer immediately (18th December) following the Which? template to state my intention to reject the car. Also attempted to ring them but no answer (10 mins before closing time).

Sent a paper copy via special delivery 19th December, which has arrived this morning (20th December) with proof of postage & delivery.

Also rang the garage who after a bit of back and forth have requested to see the vehicle on Monday 22nd December, with them collecting the vehicle from home.

I do not want them to attempt a repair and hand it back to me; I have made this clear each time I have spoken to them. I am wary of a sub-par repair being done on an already compromised engine.

They have not replied to any emails and seem reluctant to put anything in writing. I have been making a note of every interaction and also emailing them a summary of any phone calls that have taken place.

Is there anything else I should be doing to smooth along the process of getting my money back? I am concerned with the closeness to the 30 day right to return window - and the lateness of all the emails they are trying to kick it along beyond the 30 days and plead ignorance to receiving any emails.

Edited by Pugly on Saturday 20th December 13:24

Someone will be along shortly.

[Trevor555]

Sorry to hear that.

Great that you've emailed them on day 29 informing them of the fault.

Let them have a look on the 22nd, and go from there.

Forget any talk about the warranty they gave you, they have limits etc, your problem is covered by the CRA.

Hopefully the garage will just refund you as requested, otherwise it can take time to enforce your rights (whilst not being able to use the car)

Update us on the 22nd.

[ZX10R NIN]

You need to let them look at it & give you their answer & then go from there, saying anything before that will just be speculation & what you need are facts.

[Trevor555]

How are you getting on OP?

[Pugly]

Apologies for the slow response, still ongoing.

Supplying dealer collected on the 22nd December as agreed, they had it until yesterday (6th January).

They rang me on the 3rd January to tell me they'd found the fault (Vacuum pump) and had replaced it and all was well again. Vacuum pump is driven internally so would explain the sound through the sump.

Dropped off 6th January, old part was brought back to see the fault and truck sounded fine after a ~35 min journey.

Started the truck again the same day, a few hours later so it had cooled off, and its still not sounding right, it sounds different so think at least part of the issue is resolved.

Back on the phone to dealer who are starting to get less friendly, said again about rejecting and he's said I can't reject as not fit for purpose when it's just a noise and the vehicle drives fine.

He has also said it's a 100k mile, 8 year old pick up truck and that sort of noise is to be expected.

I disagree with both of the above statements but it shows a little of where the dealer is at. I am undecided now whether to pursue rejecting as I know it can take a long time to enforce my rights and I have struggled for the last 3 weeks without a vehicle, as well as I will lose money already spent on the vehicle (personalisation rather than repair costs).

Regardless, he has said to bring the vehicle back to the dealership (30 min drive away) and they will 'have a look'.

I have done some more digging of my own and think there may be a fault with the DPF; the oil level has risen and stinks of diesel, both of which are common tell-tales of a failed regen in this sort of vehicle.

I am going to try and confirm the fault is in the DPF before I send it back to them for repair (again).

[paul_c123]

You say truck - was this bought as a private purchase (ie, consumer) or for a business (B2B, SOGA applies not CRA).

[Pugly]

paul_c123 said:

You say truck - was this bought as a private purchase (ie, consumer) or for a business (B2B, SOGA applies not CRA).

Private purchase, personal vehicle 👍

[OPUT]

Pugly said:

[snip]
Back on the phone to dealer who are starting to get less friendly, said again about rejecting and he's said I can't reject as not fit for purpose when it's just a noise and the vehicle drives fine.

He has also said it's a 100k mile, 8 year old pick up truck and that sort of noise is to be expected.

Hmm, this doesn't seem a totally unreasonable position to me... Clearly it depends on what the noise is, but it seems to me that if it drives fine, it's down to you to show its an issue that means the vehicle isn't fit for purpose...

[t.boydy]

Explain how it’s not fit for purpose? Assume it starts, runs, drives etc?
100k miles and you expect a minter? Give your head a wobble

[Trevor555]

Pugly said:

Regardless, he has said to bring the vehicle back to the dealership (30 min drive away) and they will 'have a look'.

I have done some more digging of my own and think there may be a fault with the DPF; the oil level has risen and stinks of diesel, both of which are common tell-tales of a failed regen in this sort of vehicle.

I am going to try and confirm the fault is in the DPF before I send it back to them for repair (again).

Again, sorry to hear that.

Let the dealer have another look.

If they don't accept it's faulty then you'll have to get your own diagnosis done.

If the oil level is rising, that can't be ignored, as you probably know.

Then I guess you'll have two options.

1. Go for a refund

2. Get the work done yourself if the dealer refuses, and present them with the bill.

Both will probably be long winded, but at least with option two you'll only lose use of the truck whilst it's being repaired, and then pursue the costs afterwards.

If the dealer's final position is they're not helping, then contact Citizens advice, and they'll talk you through your options and give you a case number.

Quote that CAB case number when you email the dealer to let them know what you're doing. It can sometimes make them think you'll not just disappear.

Just a note about getting your own diagnosis done, Main dealer is best, rather than a small local garage.

The last case I had with Bmw, they insisted it was done by a Dekra backed diagnosis.

[Pugly]

t.boydy said:

Explain how it s not fit for purpose? Assume it starts, runs, drives etc?
100k miles and you expect a minter? Give your head a wobble

Always one, you absolute sausage.

It's not fit for purpose as the oil less than 300 miles from being changed is contaminated with diesel, and there's a mystery noise that no one seems to be able to pinpoint.

Am I supposed to change the oil every 300 miles and wear ear defenders to drive every car over 8 years old and 100k miles?

I, and no one else it seems, has no idea whether that noise will turn into a major failure 50 miles or 5000 miles down the road, and I'm expected to accept this on a £10k+ vehicle I use as family transport?

[paul_c123]

Pugly said:

Always one, you absolute sausage.

It's not fit for purpose as the oil less than 300 miles from being changed is contaminated with diesel, and there's a mystery noise that no one seems to be able to pinpoint.

Am I supposed to change the oil every 300 miles and wear ear defenders to drive every car over 8 years old and 100k miles?

I, and no one else it seems, has no idea whether that noise will turn into a major failure 50 miles or 5000 miles down the road, and I'm expected to accept this on a £10k+ vehicle I use as family transport?

You need to

1) Allow the dealer to once again diagnose what the knocking noise and/or other issues are with the vehicle. Note, they don't have an automatic right to choose to repair instead of refund - they get one chance and they've had it. But they must recognise there is a fault for a rejection.
2) If the above doesn't happen or they deny a fault, get the vehicle checked independently, for example ACE https://www.ace-uk.website/

Once the above is done you know whether your case has legs.

[Pugly]

Trevor555 said:

Pugly said:

Regardless, he has said to bring the vehicle back to the dealership (30 min drive away) and they will 'have a look'.

I have done some more digging of my own and think there may be a fault with the DPF; the oil level has risen and stinks of diesel, both of which are common tell-tales of a failed regen in this sort of vehicle.

I am going to try and confirm the fault is in the DPF before I send it back to them for repair (again).

Again, sorry to hear that.

Let the dealer have another look.

If they don't accept it's faulty then you'll have to get your own diagnosis done.

If the oil level is rising, that can't be ignored, as you probably know.

Then I guess you'll have two options.

1. Go for a refund

2. Get the work done yourself if the dealer refuses, and present them with the bill.

Both will probably be long winded, but at least with option two you'll only lose use of the truck whilst it's being repaired, and then pursue the costs afterwards.

If the dealer's final position is they're not helping, then contact Citizens advice, and they'll talk you through your options and give you a case number.

Quote that CAB case number when you email the dealer to let them know what you're doing. It can sometimes make them think you'll not just disappear.

Just a note about getting your own diagnosis done, Main dealer is best, rather than a small local garage.

The last case I had with Bmw, they insisted it was done by a Dekra backed diagnosis.

Thank you for the helpful advice.

I am avoiding driving it (again) now I've seen the oil level on the rise.

I am hopeful if I can at least point them in the direction of something to look at it'll help keep things moving as well as show I am trying my best to work with them.

I am expecting a long winded resolution whichever way it goes.

I've used the CAB online tool but if it does turn hostile then I will raise an official case, thanks for that.

[fflump]

You could get the oil independently analysed for diesel contamination which is hard for them to argue against.

In the mean time a rough and ready paper blotter test you can do to corroborate the smell you're getting along with rising oil levels.

[ADJimbo]

Everyone appears to be trotting out the ‘fitness for purpose’ line and debating whether or not a 100k mile vehicle with a mechanical noise does, or does not, meet that test of fitness for purpose.

This is a moot point. It may, or may not, meet a test of fitness for purpose.

Widen the scope of your argument back to the dealer if needed.

You also have s.9 (of satisfactory quality) and s.11 (as described) to play with here - of which, a vehicle of £10k in value, then it should be of satisfactory quality and as described, which will be easier to argue rather than a single track of fitness for purpose when mirrored against the money spent.

For a £10,000 sale to a consumer then it is easier to argue s.9 as a breach, and on the assumption they didn’t sell it as a trade disposal, run s.11 as they described it as a working motor vehicle. Run these in pararell to the s.10 fitness for purpose.

This gives you three breaches, opposed to the one breach being discussed and debated here.

[Dog Biscuit]

Diesel in the oil can be as a result of failed DPF regens

Crap scenario to be in OP.

[Pugly]

ADJimbo said:

Everyone appears to be trotting out the fitness for purpose line and debating whether or not a 100k mile vehicle with a mechanical noise does, or does not, meet that test of fitness for purpose.

This is a moot point. It may, or may not, meet a test of fitness for purpose.

Widen the scope of your argument back to the dealer if needed.

You also have s.9 (of satisfactory quality) and s.11 (as described) to play with here - of which, a vehicle of £10k in value, then it should be of satisfactory quality and as described, which will be easier to argue rather than a single track of fitness for purpose when mirrored against the money spent.

For a £10,000 sale to a consumer then it is easier to argue s.9 as a breach, and on the assumption they didn t sell it as a trade disposal, run s.11 as they described it as a working motor vehicle. Run these in pararell to the s.10 fitness for purpose.

This gives you three breaches, opposed to the one breach being discussed and debated here.

Thank you very much, some very useful info in your post that I was not aware of. It was not bought as a trade disposal or similar and was supplied as a functional motor vehicle with 12 months ticket.

[Pugly]

Dog Biscuit said:

Diesel in the oil can be as a result of failed DPF regens

Crap scenario to be in OP.

Thanks, I was hoping the DPF would shed some clues but having plugged in today the DPF appears to be in fine fettle with minimal soot or pressure differential pre/post so I'm back to square one.

The only slight cause for concern in the DPF data was 750cc of oil dilution recorded, but the time frame for that is unknown as doesn't indicate when the oil dilution counter was reset.

The dealer did start stripping the truck for a timing chain before finding the fault with the vacuum pump, and had already removed the injectors so they have had new injector seals. I am wondering if they've made a mistake, or the contamination has happened while doing the work.

Clutching at straws really.

[maz8062]

Who'd want to be a car dealer? These types of stories are why "px, trade sale only" are so prevalent.

Buying a second-hand car with 100k is a huge risk. Why no warranty claim? Straight to rejection - buyers remorse perhaps.