Thursday, March 19, 2009

Oil Pressure vs Oil Temp.

There is heavy rain today before we are off from work. This rain significantly cooled down the car's engine. I took a look at the gauges and below are some of my observation.
1) When i start up the car from cold, Oil Temp is less than 50 degC but the Oil Pressure shoots up to 6kg/cm2 (Engine rev at ~1k).
2) After waited for a while, oil temp reaches 50degC and Oil Pressure drops to 5kg/cm2.
3) After a few minutes of cruising drive, oil temp goes up and stabilize at 85 degC and Oil pressure drops to a stabilize 2kg/cm2 (Engine rev at ~1k).
With this observation; we can see that as temperature goes up but the oil pressure will drop. This normal is due to the effect of increasing engine heat causes the oil viscosity to drop. Lower viscosity oil means that the oil can be compressed more thus lowering the pressure at the same engine rev (1k).
Therefore it is advisable to let your engine to heat up for 1~2 minutes before start driving it to ensure the oil viscosity is at lower optimum spec which is able to flow and protect your engine life by reducing wear. If you drive your car hard immediately after cold start, you may cause much more wear in your engine component as its lubrication is not optimized yet.(Hope this helps 4 newbies)

2 comments:

Koh said...

I agree... always let your engine get to working temperature before have fun with it... :P

Vince said...

I do not really mean have "fun" only need to do that. I let the engine warm up for 2 minutes daily (the oil pressure will go to 3kg/cm2 after 2 minutes) then only i start driving it. Fixing this engine is not cheap so i better be careful. Now that i know how the BHP SynGard 6000 will react in my car engine, i will probably explore a little more :P.