I just did a 8000km OCI on my 1998 4Runner with 325,000kms on the engine on 5W30 Quaker State Defy. Im not 100% sure, but the oil coming out did seem thicker than normal. It might be because the engine wasn't warm when I drained the oil but I'm not entirely sure.
I plan on sending a sample to Blackstone for analysis. Out of curiosity, what would be the point in which an oil sample is considered sludging? Do you look for viscosity being out of spec? High insolubles?
I plan on sending a sample to Blackstone for analysis. Out of curiosity, what would be the point in which an oil sample is considered sludging? Do you look for viscosity being out of spec? High insolubles?