The popularity of pickups, and the noises they develop

Among the reasons I usually give are road conditions and Thailand's weather. Although roads in this country have improved dramatically in the past 20 years, you can find surface damage on roads almost every kilometre. Harsh weather plus floods, washouts and landslides also damage the roads. These things make pickups, especially those with four-wheel drive, more versatile than other vehicles in the same price range.

Now to today's questions. Khun tod 123 tells me he drives an Isuzu D-Max Cab-4 LS (the model without common rail injection) and that it has covered more than 125,000 kilometres. He drives it all over the country and even into neighbouring countries, and it has been running well.

However, he now has a problem. Each time he starts off in first gear, there is a metallic clanking noise from the rear.

He asks what is the reason for the noise and how can he get rid of it?

He should begin by checking the rear differential, which he can do himself. First, park the truck on a level area and engage the parking brake. Also place a rock or a solid object behind the wheel, so the vehicle won't move. It can also be raised so it's easier to get underneath it. Engage either first or reverse gear and then slip beneath the truck. Hold the drive shaft and spin it left and right and listen for a metallic sound. If the noise can be heard, then the problem is surely with the rear differential.

In this case, he needs to have the differential removed and the spacing between the gears checked. If it is too wide, it can be adjusted. However, if there is physical damage, it cannot be repaired, and the only solution is to replace it. Used differentials can be found easily at used parts stores, but Khun tod 123 will need the four-wheel-drive type with limited slip.

Noises like this mostly develop after abusive driving, such as taking off rapidly and spinning the drive wheels. They can also come from regularly shifting down the gears at high speed. Vehicles that need to carry heavy loads and four-wheel-drive vehicles that often need to accelerate out of deep holes can also suffer from this problem.

Khun tod 123 goes on to say he likes to wash his truck regularly and sprays water into the engine compartment to clean it, because he often drives through areas with lots of dust. His friend tells him he could damage the engine by doing this, but a mechanic at his service centre says it's okay, because all electrical parts are sealed.

Whom, he asks, should he believe?

I come down on the side of his friend, because even if the electrical systems are sealed, I don't see any reason to spray water into the engine compartment. There are a lot of electronics in modern vehicles, and we often find manufacturing defects that mean the seals are not as good as they should be. If water makes its way into these systems and causes a short circuit, then the resulting damage will far outweigh the pleasure of having a clean engine. So I don't recommend it.

If the engine compartment is really dirty, apply some kerosene and water solution, or dishwashing liquid on a piece of cloth, and clean it. Just make sure you don't knock any plugs loose in the process.

By Pattanadesh Asasappakij

E-mail your motoring questions to Pattanadesh@nationgroup.com.

Ultimate in Luxury

The Luxury LS 460 is a wonderfully comfaortable car fitted with all mod cons, althoough not necessarily the most fun vehicle to drive.