My Wifes Car Has Had A New Engine, Do We Need To Inform The Dvla?

[Impret-Sir]

My wifes Fiesta suffered the dreaded 1Lt ecoboom total failure, and has had a brand new, identical replacement fitted. Of course now the engine number is different from the V5.Our mechanic says we dont have to inform DVLA, but Im not sue thats correct, a Google search produces responses for and against!

[Grumpygrandad]

Why not contact the DVLA, and get the correct answer?

[ABerrant]

https://www.gov.uk/change-vehicle-details-registration-certificate

[Buenchico]

ABerrant's link states that you need to notify DVLA if you change the engine. I initially wondered if that might only apply if the actual type of engine (e.g. its cc) was being changed but, having looked at the V5C for my own car, I see that the engine number is given there. So it seems clear to me that you're required to get the V5C amended.

(However I'm sure that many people don't bother to update the V5C for their vehicle when changes are made to it. My friend bought a campervan that was described as a minibus on the V5C as it was a conversion job. It stayed that way until she had the vehicle scrapped many years later, without anyone ever questioning it).

[barry1010]

I would for three reasons.
Insurance company could be difficult if the car is written off and the engine number is different.
I always check the engine number when I buy a used car, I don't want one with stolen parts nor the hassle of explaining to the insurance company or police without evidence.
If the car is stolen the police might question why the vehicle they recovered (it dies happen occasionally) has a different number. It is a major vehicle identifier.