Main bearing knock – how to confirm without teardown?
Deep knock from front of engine on my 1.6 HDi Partner when revving in neutral. Oil changed recently, pressure good. Sounds like main bearings. Any non-invasive tests before pulling engine? Planning bottom end anyway.



Main bearing knock is usually low-pitched, worsens with load/revs, sometimes louder when hot. To confirm: check oil pressure with gauge (drop under load = bad), listen with stethoscope (louder at block mains), or cut oil filter for metal. But definitive is teardown and plastigauge. I suspected mains on mine- did partial drop, bearings were spun. Replaced with new mains/rod set from https://elartcom.eu/categories/engine-block-and-crankshaft-141 - they had bearing kits for PSA 1.6 HDi plus crank thrust bearings. Journals polished okay, no scoring. Knock vanished, engine quiet again. If you're in there, check oil pump too. Their selection includes block girdles if your engine uses one- handy for full refresh.