I was getting about 430 to 450 miles to a tank of diesel and its dropped to about 300 to a tank. Anyone have any pointers as to what might need changing? or checks i can make on it. The van is a volkswagen transporter 1900cc turbo diesel 1997.
- With that big a drop I would agree, look carefully for a leak. Put a bunch of news paper under and watch for leaks with engine running.
- If you’ve tried the obvious things like tyre pressure, oil filter and putting an injector cleaner in with your fuel then just give your local garage a ring and ask their advice, they should be able to give you general advice over the phone.
- Unless there is a malfunction in your van (usually signaled by the check engine light) there are two items than can cause a noticeable drop in fuel economy.
1.-clogged air filter
Easy to check and inexpensible to fix. try that first and verify mileage.
- Check that there is no diesel escaping from the return line on the injector pump which would mean that you are loosing all the unburnt fuel instead of it being returned to the tank. If this is not the problem then it is most likely either the fuel injection pump or the injectors themselves which need to be re-conditioned (done up) as they say in the motor trade.
- Unfortunately, there are many reasons as to why your milage would drop. If the weather is cold, your vehicle will spend more time idling up just to warm up. Cold air is also more dense which can result in a richer air to fuel mixture (more gas). You may need to replace one of many intake or exhaust parts, especially in an older vehicle.