donbrew

Do you understand what the oil viscosity numbers mean?

It does not make any sense running 10W-30 instead of 5W-30 in hot weather. The first number is the viscosity at cold start, the second is at hot temp.

Slide_Rite

Yes, I do. Seems to make sense to me (& many others), higher viscosity when cold equates to thicker oil upon startup. This is a common practice in hot climates, like TX. After all, startup can be one of the most demanding times for any motor.

However, since there a previous posts advising GM Mechs state the thicker oil can cause codes/failure, I am going to refrain from it & use 5w-30 going forward.

donbrew

Why would you need thicker oil on start? You want less oil flow on cold starts? You seem to be saying that in extremely cold climates one should use 20w-30, because the thicker the oil at cold start the better? Forget the crankshaft in the sump for the moment.

The engineers base the viscosity on the flow, modern engines have smaller journals than the old flat heads. The thicker the oil is the less flow, you might as well dry start on purpose.

I think you may be listening to a really old timey mechanics from the single weight days. This is the 21st century.

There is a difference between the old 10-30 and the new 10w-30 specifications.

When it comes to the VVT valves the lower weight is essential to operation. Just to keep this germane.

whopper

As this is the how-to section, and this how-to article has been documented to death with instructions, tips and hints, we are closing this thread, as it has started to turn into a discussion thread, often hijacking it's intent.

If you have a question relating to the p0010/14 codes and the actuator replacement, feel free to post in another of the forums, such as the Problem one.

I'll try and keep the initial post updated with any changed part numbers etc.