340,000 KM 2003 Accord Ex Oil Viscosity Issue
 

Here's the latest word on 5w20 vs 0w30 viscosity in a 2003 Honda
Accord EX. i am sure that many of you have wondered and read about why
certain companies like Honda and Ford are using 5w20 insead of say
5w30 or 5w40 as in European cars. Contrary to the popular belief that
Honda used 5w20 to meet CAFE requirements it is mostly due to engine
tolerances. I have recently opened the Accord engine cover to examine
the valve clearance as the valves started to get a bit noisy. To my
surprise I have noticed slight groves and pitting in the cam lobes. A
mechanis from the US has asked me if I were using a wrong oil. I asked
what is wrong oil. He asked whether I used a higher viscosity oil
higher than 5w20. I said I used Amsoil 0w30. What he claimed is that
the camshafts did not get adequate volume of oil and the fact that
they are the furthest in oil circuit, they got less oil than they
should have due to lower flow of oil. This is theoretically possible,
but I am not sure that pitting of the lobe material is due to reduced
lubication. To me it looks like poor quality of material or poor
quality control during manufacturing of the camshafts. The vehicle
still does not burn more oil than it did when it was much newer i.e.
0.5l per 10,000Km. I am now going to switch to synthetic 5w20 in hope
that the cams and the followers will last until 500,000Km. Does anyone
have similar experience with their camshafts?

Dan.