Engine noise but no warning lights

[EmilyM]

Engine suddenly started making metallic grinding sound and prompted driver to pull over last week. It had low oil so suspect possible engine seizure or partial seizure. Garage suggests replacing engine. However drives in EV, no codes come up on mechanic's diagnostic tool. Drives in low power. Do we take apart to rebuild or go for whole engine swap? Finding it hard to get a second opinion so wonder if anyone has advice. Thanks

 

[kpetrov]

One can basically drive the cat without an engine, so no concern there even if it trows some errors.

Regarding the engine it will be hard to tell over the internet some experienced mechanic should hear it.

 

[DaveL59]

I'd agree that it needs an experienced mechanic to take a look rather than hope for some internet diagnosis. Any number of things could have happened, depending on how low the oil got and what load the engine was under. If you decide to go for stripping the engine down and rebuilding you could find bearing shells, crank, camshafts and pistons/bores scored, chain damage and who knows what else. The labour and parts costs may quickly overtake a replacement engine.

If getting a used engine tho would it be a refurb or just secondhand? You'd ideally want one with a service history and get things like the chain and tensioners replaced before fitting I'd suggest, one less thing to worry about for a while at least.