Make it last
I have a recently rebuilt Windsor 289 cubic inch V8 but don’t know what components were built into it. With modern rebuilds, does the engine still require the valve lubricant to be added to the fuel? I have been adding it along with premium fuel just in case. Would that do any harm longterm if it wasn’t necessary?
Sam, email If hardened valves and valve seats were fitted in the rebuild, you wouldn’t need to use an additive, but it’s unlikely that they were, so it would be best that you use one. Adding it won’t do any harm should it turn out that you have hardened valve seats. GOOD INTERVAL I regularly change the oil and filter in my 2000 Daewoo, every 5000km in fact. Would this be considered over-servicing?
Darcymckee Changing oil and filters regularly is good insurance for the longevity of your engine, and 5000km is a good interval. TRUE MILEAGE The 1996 Holden Combo that I picked up cheap with 190,000km on the clock seems to have power issues. When I accelerate I either lose power or it feels as if I’m towing a 100-tonne excavator. I’ve replaced the exhaust, the plugs and leads, the throttle body, map sensor, fuel filter, oil filter and everything I can think of. Ive also checked the fuel pump and it’s working fine.
Chris Dowling, email Are you confident that the odometer reading is correct and it hasn’t done a lot more than the 190,000km it’s showing? Check the compression— the engine could simply be worn out. GAS DOES HEAD IN We converted our 2002 Corolla to gas in 2008 and have just had the head rebuilt due to burnt valves. The seats have been replaced but we have been informed that it is inadvisable to use gas, as the problem is likely to return. We have discovered that the gas can be augmented with a drip-feed additive lubricant which may ‘‘cool’’ the combustion. Manufacturers of the ‘‘drip-feed’’ lubricants produce sales brochures with generalised comments extolling the protective properties of their product, but no empirical facts to substantiate the product’s use. Further inquiries have unearthed another apparently strange approach, which is to run the vehicle on petrol for a quarter tank for every full tank of gas. The use of petrol over, say, a run of 100km and then gas for, say, 400km to create a long-term beneficial residual influence from the petrol does not appear to be logical. It is suspected this approach has been more to ensure that petrol does not go stale in the tank. It has also been suggested that the engine management system should be checked regularly to ensure that petrol and more importantly, the gas mixture, is not too lean. What is correct?
Ian, email The repairers of your cylinder head should have used Lpg-compatible valves and valve seats; had they done so you would not have any further
Keep it fresh: Daewoos of this vintage need oil changes at 5000km intervals