Have you checked the plastic liner/wheel arch to ensure it is free from dirt and not bent? I know of a similar case where on a turn the driver could hear grinding. It was the result of the wheel coming into contact with the plastic. If you have a garage nearby ask for an inspection. Just make sure to view any stated damage/problems yourself prior to agreeing to work being carried out.

Two weeks ago I got my 1993 BMW 740i E32 (4 litre V8) stuck in floodwater. Ended up taking water into the engine and exhaust, not to mention about 2 inches inside from front to back!

Here’s how we fixed it – note that I am not a professional mechanic and you try this at your own risk – it’s simply my documenting the process we followed to rescue my car:

1. DO NOT TRY TO RESTART THE ENGINE WITH SPARK PLUGS IN. This is just about the worst thing you can do!

2. Let the engine bay drip-dry overnight to ensure there’s no major water ingress into the under-the-hood electrics. Remove the spark plugs from the engine and remove the air filter unless it’s absolutely bone dry.

3. Turn the engine over on the starter. This will expel any water that’s been taken in. Do this 6 or 7 times until the engine turns over with no sign of anything being sprayed out.

4. Clean the plugs and re-install them.

5. Now, try and start the engine. If you’re lucky (I was), it should fire fairly quickly, though it might sound like a bag of spanners for a while especially if you got a lot of water in the exhaust. When we got my engine started, about a gallon of water shot out of the exhaust in 5 seconds!

6. Let the engine idle for 5 minutes and listen for any obvious misfires. Use this opportunity to check that all the belts etc. are functional. You’ll probably get *a lot* of white smoke from the exhaust – don’t panic it’s only steam as the water taken in starts to evaporate as the exhaust gets hot.

7. If you’re good so far, now is the time to change the engine oil and oil filter. Install a new air filter at the same time.

8. Now fire her up again, repeat the idle process then once the oil is at temperature slowly increase the engine speed up to about 5k (or 1k below whatever your motor red-lines at) – again expect a lot of steam from the exhaust.

9. In daylight, take the car for a short, slow, test drive on private ground or straight road and check the brakes/transmission. Try not to use anything electrical (indicators, lights etc.)

10. If water got into the car (if the carpets are damp, it did!) run a dehumidifier for 3 days or longer if necessary until the carpets are bone dry to the touch. I got a good 15 pints out of mine over 4 days *after* mopping up the obvious surface water with towels.

11. Now, test the electrics. Lights, indicators, etc. Take the car for another short, slow test run testing everything as you go.

12. If you’ve made it this far, chances are you got away with it! You now need to take the car for a long run to get the exhaust fully up to temperature for a long period to help clear any residual water trapped in there. I would suggest at least 3 or 4 50 mile journeys within a couple of days. You’ll probably see the steam for some time and don’t forget to take your breakdown membership with you in case it goes horribly wrong.

Good luck!