Thin oil and hydraulic lifters

[Malek@MRF]

Originally Posted by Doc Oc

Thanks for the reply. Is there anyway this 8-10 psi drop could have a detrimental effect on anything? I know thinner oil gets where it is supposed to go quicker on startup but I'm wondering if this loss of oil pressure negates that at all? And given that psi drop, wouldn't it be wise to go with the thickest 0w40 available if you are going to switch to that weight?

I don't see how it could have a detrimental affect on anything at all. Fact is, the oil pressure, even with 0W-40 is well within the acceptable range.

BMW Recommended specifications are as follows:

• Oil Pressure @ idle speed with engine at operating temp: Minimum of 1 Bar (14.5 psi)
• Control Pressure with engine @ operating temp: 4.0-6.0 Bar
• (58-87 psi)

At idle with 0W-40, oil pressure stands at a solid 42-48 psi and in the high range at operating temp oil reaches 80psi when the engine is loaded more heavily.

It is evident that these engines need to be warmed up significantly. As a crude way of explaining, if you start driving the car (with M1 0W-40 oil) and the OE oil temp gauge hasn't reached the first "dot", oil pressure is spiking well above 87 psi, repeatedly. It is crucial that these engines be warmed up liberally and driven lightly until at correct operating temperature. Another generic way of monitoring if you have reached operating temp? When the electronic dipstick begins to show the spinning clock. If the spinning clock is not present and the dipstick is still showing "-_-", it will not measure the oil level as it is not at what it considers to be operating temperature.

[Doc Oc]

Originally Posted by Malek@MRF

I don't see how it could have a detrimental affect on anything at all. Fact is, the oil pressure, even with 0W-40 is well within the acceptable range.

BMW Recommended specifications are as follows:

• Oil Pressure @ idle speed with engine at operating temp: Minimum of 1 Bar (14.5 psi)
• Control Pressure with engine @ operating temp: 4.0-6.0 Bar
• (58-87 psi)

At idle with 0W-40, oil pressure stands at a solid 42-48 psi and in the high range at operating temp oil reaches 80psi when the engine is loaded more heavily.

It is evident that these engines need to be warmed up significantly. As a crude way of explaining, if you start driving the car (with M1 0W-40 oil) and the OE oil temp gauge hasn't reached the first "dot", oil pressure is spiking well above 87 psi, repeatedly. It is crucial that these engines be warmed up liberally and driven lightly until at correct operating temperature. Another generic way of monitoring if you have reached operating temp? When the electronic dipstick begins to show the spinning clock. If the spinning clock is not present and the dipstick is still showing "-_-", it will not measure the oil level as it is not at what it considers to be operating temperature.

Thanks! The spinning clock is always what I use as an indicator. It is amazing how often the needle will show it is up to temp but the gauge isn't even spinning yet.