Hi all, new member here joined due to an infuriating problem with an insurance company. I was rear ended recently quite hard and the moment of the impact my vehicle immediately started sounding like a diesel. The other driver has admitted liability and off went the car to the repairers. They then claimed the car was only carrying 1.8 litres of oil and the engine was already damaged. My initial thought was that an impact to the exhaust may have caused something. The car has been returned to me following the replacement of a bumper and crash bar and repair to the boot floor pan/ spair wheel well(this is another bone of contention as I don't like bent metal being reshaped) however the engine problem hasn't been touched. I am aware of this sounding like a tall story but it genuinely started being noisy at the moment of impact and my first thought was tappets for some reason. The car runs fine apart from tick over after revving. It appears to hunt then stall... Starting is non problematic as is maintaining revs. Just the horrid regular tapping noise and stall on return to idle... Any ideas? I have an insurance inspector coming tomorrow. Thanks in advance.

I am no mechanic but a regular driveway hero. There was no build up to this, no hints of low oil such as when cornering, no warning lights nothing... Literally bump then rattle!

What speed do you estimate the impact was ? were you stationary or moving ?

I'm speculating that the exhaust system is damaged & is rattling / exhaust manifold has cracked & is rattling - as I can't imagine a rear impact affecting the engine

Thanks for replies gents. I estimate the speed of the impact to have been about 20 mph ish. I was stationary, engine running, foot on the break and clutch with 1st selected

Did your foot come off the clutch & the car stalled ?

Also, sorry, would the manifold being cracked cause the bad return to idle? And is there an easy way to check this?

I honestly can't remember that... I think the engine remained running and started with the noise immediately. There was no gentle build up as you would expect if oil starvation was starting anywhere like the lifters

I'm thinking the impact has damaged the exhaust system somewhere & that's causing the diesel like rattle - or if the car stalled then maybe a gearbox component got a heavy shock ?

A damaged exhaust manifold will affect back pressure which could affect smooth engine running