4x4 Mag - Technical Tips

Technical Tips - September 1999

by John Deaville and Graham Scott

Overheating

My 1989 Toyota Land Cruiser overheats in traffic or when moving slowly. It has a mechanical fan fitted which is working OK. What's the problem ?

First of all check the condition of your radiator outside and in ! If the water is a browny sludge colour, you must flush the cooling system out. Take off a bottom hose releasing all the water, then remove a top hose and run water through the system. Inspect the outside of the radiator core for signs of rot. If everything seems OK after this inspection refill the radiator and warm the engine up. Switch off the engine and inspect the radiator to see if there are any cold sections of the radiator core. This would indicate if the radiator has severe blockages.

Four Star

With the demise of 4 star fuel in the near future can I run my EFI Range Rover on unleaded and if so will it need any adjustment to the timing that the local garage has told me it will need ?

You can use unleaded fuel in your Range Rover, the EFI engine will run on this without any adjustment to the timing.

Tyre Size

Can you tell me what is the biggest tyre I can fit on my two door Range Rover ? It currently has 205-16 Michelins on the original Rostyle wheels.

235/70R16 is the largest tyre you can fit without embarking upon modifications to the wheel arches. This size tyre will greatly enhance the vehicles handling. It may also be time to change to alloy wheels which will also reduce the unsprung weight of the wheel/tyre assembly, considering the increased physical weight of the 235 profile tyre.

Diff Lock

When I've been off-roading in my Land Rover 90 and have had the differential lock engaged there is a noise from the transmission / axles. What is it ?

The noise is due to "wind up" in the transmission due to the diff lock being engaged when there is no likely event in the loss of traction by one or more of the wheels. To solve this problem only use the diff lock if you think you are going to lose traction and disengage afterwards straight away. Doing a figure of eight will remove wind up from the transmission if it happens again.

Stainless ...

I wish to fit a stainless steel exhaust to my 1994 Nissan Patrol. What is meant by a lifetime guarantee ?

Stainless steel systems are great if you intend to keep the vehicle for a long time because then you'll have the benefit of the additional cost over mild steel systems during long periods of vehicle ownership. Watch out for the "Lifetime Guarantee", invariably this is only operational while the person who purchased the exhaust still owns the vehicle. Also what if you damage the system while off-roading. Check with the manufacturer/supplier, always best to enquire with a few companies before hand. On a technical side make sure you are purchasing a system with a high stainless steel content, I've seen many "stainless systems" rusting at the joints early on in their life !

Send your technical queries to : richard@4x4mag.co.uk