Took my car for a test drive after finding water in engine bay fuse box, and leaving a 30mph in 5th engine went out of control full revs, tons of black smoke but managed to get it into layby and turn off

17 hours ago, Crocky1966 said:

Took my car for a test drive after finding water in engine bay fuse box, and leaving a 30mph in 5th engine went out of control full revs, tons of black smoke but managed to get it into layby and turn off

Hi probably not but had it been mine I would have treated the fuse box to a generous helping of WD40 and then left it overnight then give it another hosing down and then driven it, its most likely where the water has caused a short somewhere but the other thing to look at coincidentally would be the oil level as if the turbo seals have gone the engine will use its own oil to run on until she blows but thinking about your thread it wouldn't have let you turn it off you would have had to stall it to shut it down.

Steve.

19 hours ago, Crocky1966 said:

Took my car for a test drive after finding water in engine bay fuse box, and leaving a 30mph in 5th engine went out of control full revs, tons of black smoke but managed to get it into layby and turn off

Don't think you will have killed the engine but electrics are another matter...  if it was my car  I would dry out the fuse box thoroughly  and use contact cleaner on the fuses and relays, find how the water is getting in and stop it. Water and electrics are never a good mix

Late to the party but wd40 is water displacement 40th edition and not the pen oil many think it is. A liberal spray will get electronics out of many damp/wet issues 

If the fuse box is at either end of your dashboard or under the glove box, a likely cause of the water is leaves in the bulkhead stopping it from draining. 

If you open the bonnet you should be able to remove the plastic covers and clean the drainage area out. You should also have grommets underneath which you can remove and poke from the bottom. 

The other common issue is if you have a a sunroof and the drain is blocked. 

 

Fingers crossed it's just a blown fuse 👍