Q. I recently did the annual oil change on my 2004 Range Rover V8. I used 5W/30 fully synthetic oil (ACEA-C3, API-SM, CF spec). This seemed to meet the requirements listed in the RAVE technical manual.
From the first time I started the vehicle, and subsequently from cold, it over-revs to about 1500rpm for about two seconds and the engine sounds like a diesel before settling down.
Do you have any ideas what I did wrong and what I can do to fix it?
Jason Spencer, Essex
A. The Range Rover V8 can be noisy for a few seconds after starting up from cold when the oil is still quite thick. The hydraulic tappets, which control the valve clearances, may be noisy and not operate fully until the oil has circulated. Perhaps this is what you are describing when you say it sounds like a diesel. If so, this situation will not harm the engine, and is common.
Noise can also be caused by air absorbed in the oil, which is often cured by a motorway run where engine temperatures are high for a prolonged period.
The viscosity of the oil at start-up is also affected by the ambient temperature, so the noise may come and go, and at different intensities. It may also be affected by the particular oil characteristics.
Land Rover specifies an ACEA A3/B3 (petrol and light-duty diesel engines) oil for your engine, whereas you have used C3 oil that is developed for vehicles with a particulate filter and three-way catalytic convertor. The C3 type is a high-quality oil that would have the lubrication required by your engine.
The ACEA (European Automobile Manufacturers’ Association) does state however, that C-type oils are unsuitable for some engines, but without specifying which. ACEA advice is to adhere to the individual vehicle manufacturer’s specified type of oil.