Petrol Engine 4x4 Questions

A lot of people see photos of 4x4 vehicles ploughing through deep water and think that the vehicle is designed to do this. Well, try reading the manufactureres recomendations. Axle deep is the recomended wadeing depth as recomended by most manufacturers! Regular emersion in a depth over 600 mm and you had better be prepared for possible mud / water damage to wheel bearings, starter motor, alternator, differentials. On some vehicles with very low down air intakes you could even cause very heavy damage to an engine.

Most 4x4 drivers have no idea how easy it is for a vehicle to float ! If you have water up to the top of your tyres you risk haveing no traction and being at the mercy of the current if you are in moving water. You can reduce the effect of water on your engine compartment by using a wadeing curtain (eg canvas or plastic sheet across the front of vehicle), this will deflect some water from the area around the fan helping to prevent (a) The fan blades being deflected by the water and possibly damageing the radiator. (b) The water being thrown around the engine compartment and into electrical components by the fan. This can occur on both petrol and diesel engines.

Diffs need to have breather tubes fitted and run up into a high point in the engine bay or body of the vehicle. Some vehicles have the alternator fitted high up in the engine bay and some have them low down where they are more easily effected by water. Starter motors are relatively protected by being totally enclosed but not many are water tight allowing fine silt to enter and chew up the brushes.

If you want to frequently use your 4x4 in deep water (wheel height or more) you need to have a deep wallet and be prepared to open it regularly! You need to talk to lots of people with EXPERIENCE, preferably face to face rather then just read a few flipant replies from some fearless young people who enjoy having fun and making a splash but don't really know what they are doing or how close to the edge they are operating. Driving in water is not difficult but like all 4x4 driving there is no substitute for experience and local knowledge. There is no short answer to your query.

V8DIESEL & BANJO1 have reminded me about a couple more things for you to think about when driving in water.

(a) Salt ! Driving in salt water will take its toll a lot quicker then fresh water. Infact avoid it if you want to keep your truck for many years. By all means have fun if you have a cheap toy but if its an expensive 'pride & joy' avoid salt water if at all possible. The spray up under your vehicle gets into the seams and can start rotting the panels very quickly. A water blaster just doesn't manage to clear all the salt out after a run a the beach on saturated sand.

(b) Radiators collect silt and debris and can be difficult to clean. A clogged radiator may cause overheating very quickly. I would love to get rid of my air con and transmission radiators so that I can more easily clean my radiator. Some muddy water contains a lot of floating or suspended plant matter which clogs radiator cooling fins and then bakes hard with the heat of the engine. I wish radiator manufacturers would make special radiators for 4x4's that have extra large 'easy clean' gaps between cooling fins. I have spent hours sitting on a box with very small tools picking small rootlets from a peat swamp from between cooling fins. High pressure water hose moves silt but doesn't touch plant material and may also damage cooling fins.

You would be surprised how much splashing a modern Petrol engine will take, with the latest EFI and the disaperance of the Dizzy the petrol are quiet good in water.

I had a petrol 2.7 Hilux (with snorkel) which went very deep many times and it never complained however, the diffs and gearbox did :-(

I placed breathers on each but water still got in, it quickly stuffed what was left of my LSD.

I used to think water was exciting, now its just lots of hard work changing the oils. I only cross if I REALLY need to now :-)

Irrispective of it being petrol or diesel all of the above have have provided very sound advice.