Hello everyone,
I have another question about my Roadster. Now that its hot out, when i start it up after it has sit for a while, say 88 hours to 24 hours, it rattles for a second. Then, it sounds as if the lifters pump up and it quiets right down. Anyone else have this problem. I have 60,000 on it now,
Dave

 

OOps, I meant 8 hours

 

That's common and no problem.
You can go back and edit your original post, there is no need to do another post.

 

2nd opinion....I agree with Dave...it's normal...

 

Same thing happens with mine.....

 

With the correct 0w40 synthetic motor oil, you have to remember at start up it has the consistency of water, and the viscosity thickens up as it warms up.
Also, synthetic oil doesn't have the noise suppression qualities petroleum base oil has.

 

This is not true actually, oil gets thinner as it gets warmer. That applies to single and multi grade oils. It is their viscosity at certain temperatures that determine the rating on the container.

I'll add an article on it if I can find it.
http://www.upmpg.com/tech_articles/motoroil_viscosity/

 

More on this topic HERE

 

180, I just read your above mentioned article, and I don't see where anything I said contradicts it.
At start up (in a cold engine) the 0 weight viscosity flows thru the motor faster.(like water) As the engine and the oil heats up the viscosity goes up proportionally.
When the oil is at 0 viscosity, it loses most all of its noise suppression qualities as well.

 

You used the word thicken in the wrong direction, oil gets thicker when it cools. Multi grade oils have less of a slope on a graph of viscosity at a certain temperature than single grade oils.

0W 40 acts like a 0 grade oil at -30deg.C and acts like a 40 grade oil at deg.C

That's the way I understand it anyway.

 

From Question #3 in the article that you posted 180:
So how do they get a motor oil to flow in the cold when it is "thicker" viscosity at 210 degrees?
Their words, not mine.

 

Thicker is being used relatively, 40 is thicker than a 30 say.