QUESTION
My local Lotus dealer recommends using 5w40 Castrol Edge fully synthetic…is this compatible or should I purchase a good alternative such as Nulon 15w50
ANSWER
It is understood that your Lotus dealer may recommend 5W40 oil for your Lotus Esprit engine so as to maximise performance.
However when the Lotus Esprit engine was conceived, the engine components and crankshaft bearing clearances were designed around 20W50 oil.
If a flickering oil warning light is observed then this needs immediate investigation.
A flickering oil warning light will usually indicate low oil pressure within the engine.
This can be a symptom of a number of things including - partially blocked oil filter, incorrect grade of oil, contaminated oil, worn oil pump, worn engine bearings or a faulty oil pressure switch/sender unit.
In this instance it would be wise to have a close look at the electrical system and pressure switch before carrying out a more detailed investigation
With the hotter weather approaching it would be prudent to use the correct grade oil such as Mobil 1 5W50 or Nulon 15W50.
For elevated ambient air temperatures (say on a 35 degree C day in Sydney) you need the correct grade oil to maintain bearing lubrication and pressure.
If you look at the attached sheet from the Esprit service notes you can see the lighter grade oils are better suited for countries with lower ambient air temperatures.
My local Lotus dealer recommends using 5w40 Castrol Edge fully synthetic…is this compatible or should I purchase a good alternative such as Nulon 15w50
Without presuming that this is the issue, I'm getting the oil light coming on coupled with the battery warning light as well and have discovered that it completely goes (both lights) all together?
From reading the lotus manual they suggest that if the light comes on under 1600rpm coupled with the battery light then it is more likely to be a charging and or electrical issue.
I will getting the car completely checked out next week, oil pressure gauge accuracy, timing belt, minor service, crankcase breather and everything diagnostically checked over.
I will be taking an oil sample as well to be analysed.
P.D. - Sydney, AustraliaANSWER
It is understood that your Lotus dealer may recommend 5W40 oil for your Lotus Esprit engine so as to maximise performance.
However when the Lotus Esprit engine was conceived, the engine components and crankshaft bearing clearances were designed around 20W50 oil.
If a flickering oil warning light is observed then this needs immediate investigation.
A flickering oil warning light will usually indicate low oil pressure within the engine.
This can be a symptom of a number of things including - partially blocked oil filter, incorrect grade of oil, contaminated oil, worn oil pump, worn engine bearings or a faulty oil pressure switch/sender unit.
In this instance it would be wise to have a close look at the electrical system and pressure switch before carrying out a more detailed investigation
With the hotter weather approaching it would be prudent to use the correct grade oil such as Mobil 1 5W50 or Nulon 15W50.
For elevated ambient air temperatures (say on a 35 degree C day in Sydney) you need the correct grade oil to maintain bearing lubrication and pressure.
If you look at the attached sheet from the Esprit service notes you can see the lighter grade oils are better suited for countries with lower ambient air temperatures.
