As mentioned, moving from a 5W30 to a 10W30, you're still a 30 grade at operating temperatures. If there are no oil leaks and the PCV is working properly, I would try adding something towards the end of an OCI like, Kreen, Rislone, or MMO to clean up the ring packs. Run it for 1,000 miles or so and keep an eye on the oil level. Drain the sump and repeat at the last 1,000-1,500 miles of the following OCI. If that doesn't work you could move up to a 0W40 or a 5W40 oil.