Toyota HiLux 1999 Problems

An accurate comparison with contemporary competitors to the HiLux is very hard to find as these cars were built at a time when light commercial vehicles weren’t being officially tested for fuel economy as they are today. Suffice to say that fuel economy won’t be as good as a more modern vehicle with more modern engine technology and management electronics.

About the closest I can get you is a 2003 HiLux dual-cab with the 2.7-litre engine which has an official combined economy figure of 11.1 litres per 100km. But while there’s a handful of years between your car and the one I’ve just quoted, the comparison is actually relatively meaningful as the HiLux in either case is essentially the same vehicle with the same basic engine.

The thing to remember with all these official figures is that they really only stand up as a direct comparison to other vehicles of a similar type when tested against the same criteria. In the real world, you’ll really battle to get anything like the claimed fuel economy number and I’d expect a HiLux like the one you have to use at least 11 litres per 100km on the highway and closer to 14 litres or even more around the suburbs.

It is if it has a 2.2-litre or 2.4-litre engine, but not if it’s got a later 2.7-litre engine. The valve train in the smaller engines are fine for LPG, but the later 2.7-litre engine had a valve train that wasn’t suited to LPG and gave head problems until updated in the early 2000s.

IF IT'S coming in when the engine is under load it sounds like a diesel problem. It might be worth having the engine checked to make sure all is well under the bonnet, and check for displaced seals in the firewall that might be allowing the fumes to enter the cabin.