Land Rover Repair: overfill of engine oil, proper circulation, combustion chamber

Question
a guy borrowed my 1997 disco to tow a digger. he claims that the engine light came on and so he pulled over and filled with oil straight away. the car then proceeded to make very loud banging noises from the engine. when the car returned, husband checked oil level and found that it was at least 6 in overfull on dipstick. when the guys mechanic came, he revved the car until it was squeeling and smoking. when i asked what he was doing he replied that he was burning excess oil. i think that they have damaged engine but they are denying that overfilling oil so that it spills over engine would be the cause. PLEASE HELP and advise me. the disco wont even start now

Answer
Hi Andrea,

the simple answer is to have the Disco towed to the nearest LR dealership and to have assess the damage.  Inform the person who borrowed the vehicle that they will be responsible for any and all repairs.  

It may be that the the towing capacity of the vehicle was exceeded.  The maximum towing weights are listed in the owners manual:

TOWING WEIGHTS (On-road)
Unbraked trailers 1650 lbs (750kg)
Trailers with brakes - high range 5500 lb (2495 kg)
Trailers with brakes - low range 7700 lb (3490 kg)
Roof rack load 110 lb (50 kg)

What oil was added?  Clearly, adding too much can cause the crankshaft to froth up the oil and not allow proper circulation.  This will cause overheating and, in the worse case, the cylinder sleeves can drop and ruin the engine.

I've also heard that excess oil can create a residue on the intake valve stems causing them to stick open.  The result could be difficult starting, rough idle and the consequences of this.

Revving the engine to 'burn off excess' oil is foolish.  The correct method is to remove the oil from the sump and reinstall the correct amount.  High rev's can cause all sorts of damage to the combustion chamber as the pressures increase greatly if the vehicle is not in motion.  This is called 'overspeed' and the damage it can do is shorten the life of the engine, ruin the piston rings, gaskets, weaken the headgasket, possibly damage valves, add to overheating the engine...

Sounds to me like ever LR owner's worse nightmare!

Visit your local dealership and if the person who borrowed your vehicle is unwilling to pay for damages, find yourself a lawyer.  If the engine is ruined, the value is way above 'small claims' court limits.

Best of luck,

JohnMc