CSR Oil Change Process

This process has been put together to enable owners of these cars to carry out a more efficient oil change on their cars. A lot of owners may only be changing 60% of their oil due to the layout of the standard oil system.

Firstly here’s a brief explanation of how a dry sump oil system works.

Oil should be stored in the cars remote oil tank. This not only allows the engine to be fitted with a shallower sump pan, but also reduces the risk of engine failure due to oil surge, which is generated by G-force during fast cornering. You will find that the oil level is at its highest point in the tank when the oil is up to operating temperature and the engine is running. Unfortunately, there is no valve on these cars that prevents drain down of the tank when the engine is stopped. In this condition, what you have is an oil tank, full of hot, thin oil that generates a “head” of pressure on the oil that is leaving the tank and going to the engine.

Over a period of time a lot of the oil can drain out of the tank, into the engine.  This then means that when the engine is next started, the oil level in the tank will appear low.  There isn’t the “head” of oil to force the oil into the engine.  Whilst there is a pressure pump that pulls the oil from the tank, into the engine, this is more efficient, with a “head” of oil, helping to supply oil to the pump.  In addition to this, a large quantity of oil is now in the sump of the engine.   

This oil that has drained into the sump, is now cool and much thicker, meaning the scavenge pump is having to work hard to pump this thick oil back to the tank.  It has been known for scavenge pumps to fail due to the load on their drive as a result of the pump being driven too hard from cold with thick oil.  This is why oil levels should always be checked with engine oil at or near operating temperature. 

The issue with the standard CSR oil system installation;

The standard CSR sump pan doesn’t have a drain plug on the base of the sump.  There is a 32mm plug on the side of the sump, underneath the alternator that allows for some oil to be drained.  Behind this plug you should also find a gauze filter that should be inspected during oil changes.  It doesn’t need to be replaced, just ensure it is clean before refitting.  Following inspection, just give it a spray with brake cleaner to ensure it is clean.  Having drained this, there is still a volume of oil in the sump, that needs to be drained. 

As this system has internal pipework to deliver and return oil to the oil tank, hoses can’t be removed to drain oil.  So we have come up with the following process to remove as much old oil, when carrying out an oil change.

Premier Power CSR Oil Change Process;

  1. Place the car on axle stands or a lift so you can gain access to the drain plugs and oil filter under the car.
  2. Warm up the engine to operating temperature and let the coolant fan cut in.  This will ensure the oil has some temperature in it and hopefully as much oil as possible, will be in the oil tank.  Have a 32mm ring spanner ready with a drain bucket. 
  3. With the engine now hot, turn off the ignition and carefully remove the drain plug on the right hand side of the oil tank.  Drain as much oil as possible from the tank.
  4. Once drained, remove the 32mm plug from the left hand side of the sump, under the alternator and inspect the gauze filter.  Clean the gauze filter as mentioned above and then replace it and the plug.  Do not force the plug back in the hole.  If you’re having trouble getting this to start, it maybe a case that the gauze filter hasn’t located in its spigot in the sump.  Check this before trying again. Once the oil is drained from here and the plug is tight, remove the oil filter and drain the filter of the old oil.
  5. Fill the old oil filter with new oil and replace it back on the filter housing and spin it up just so it nips up.
  6. Remove the spark plugs and disconnect the fuel injector plugs from the fuel injectors.  This will prevent fuel from being injected into the cylinder when you are cranking the engine.
  7. With the drain bucket now placed back under the oil tank and this drain plug still removed, get someone to crank the engine whilst you watch the oil draining from the tank.  As soon as oil stops draining from the tank, stop cranking.  This process should take no lomger than 10 – 15 seconds.
  8. Replace the drain plug tightly, back in the tank and wipe around the base of the tank ensuring there are no drips of oil.
  9. Remove the original oil filter and discard appropriately.
  10. Fill the new oil filter to the brim with new oil and put a light smear of oil round the oil filter seal.  Give the filter housing a wipe in the sealing area of the housing and fit the new oil filter, screwing it tightly again the sealing face of the filter housing.
  11. Now fill the engine with about 6 litres of new oil.  Because the oil tank only has a small cap on the top, this would prove difficult to get the oil in.  If you have a very small funnel, this would be the preferred method, otherwise just put the oil straight in the engine.
  12. If you’ve been unable to fill the tank directly, what we now need to do, is crank the engine once again.  This will use the scavenge pump in the engine to pump oil from the engine, back to the tank.  Again do this with the spark plugs still removed and the injector plugs still disconnected.  This means the engine will turn over faster without loading the engine.  After about 10 – 15 seconds of cranking you should see oil pressure on the gauge.  Once you start to see oil pressure, continue cranking for another 10 seconds. 
  13. Turn off the ignition and refit the spark plugs and injector plugs.
  14. IT IS LIKELY AT THIS POINT, THE OIL SYSTEM WILL BE LOW ON OIL FOR DRIVING.  However the engine should now be started, initially watching the oil pressure gauge.  Again let the engine warm up and let the coolant fan cut in.  Once the fan has cut in, turn off the engine and check the oil level in the tank in accordance with the dipstick supplied by Caterham.  If oil isn’t registering on the dip stick, put another 0.5 litre in the engine and run in for a couple of minutes, then stop the engine and check the level again.  Keep doing this until the oil level is showing maximum on the dip stick.
  15. Once the level is set, have a good look around under the vehicle to ensure there are no leaks from the areas you’ve been working on.  Once the engine has cooled right down, ensure that the oil filter is nice and tight and there are no signs of any leaks.

Following this process should ensure you change a larger amount of the oil in the system.

Premier Power does offer a revised oil system for these cars that not only makes this process a lot easier, but also greatly reduces the risk of damage to the front of the sump.  This revised oil system also includes much better oil temperature control and stability.

Please contact us for further details of this if you’re interested.