Infrequent poster here and 100% dealer maintained 2007-V70R. I have a new issue that's popped up where I have a strange pulsing under heavy load. Here in Colorado, pulling up I70, we put a solid demand on our turbo. At speed and under load, the engine seems to pulse on and off power almost as if something is holding back the turbo. I've read horror stories about cracked blocks/cylinder walls, leaking coolant etc.
Could any surmise what might be occurring or what I might expect?
BTW, I have the an IPD tune from 2016, otherwise all else is stock and perfectly scheduled maintenance.