Quote:
Originally Posted by workingonit
However, when I started the engine after the fill, the Vanos made a noise I'd never heard from them before...I hope that they can accommodate thicker viscosity oil (my '09 HHR with VVT didn't like it, so I went back to 30 weight).
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In (simplistic) theory, the 5W-40 is not any thicker than the 5W-30 - at start-up when the engine is cold (the 5W part).
In practice, it is a little thicker (kv @40C is 84 vs 70) but still thinner @40C than the 5W-30 would be at say 10C.
It's likely the various noises you heard would be due to the engine being drained of oil and the slow re-fill time as the oil pressure comes up after the drain. Esp. so if the drain was more than 20-30mins (something it try to avoid doing).
I too run the "thicker" 5W-40 Castrol Edge, due to the aging engine components (turbo bearings!) and have done so since 200,000kms (70,000kms ago) but I figure it's probably more "placebo" than engineering/science.