slight rod knock

When I go start my car i get a slight rod knock for like a split second. It only does it when the car has sat overnight. I just put new rod bearings in 510miles ago along with piston rings. Could it be the ND 30w getting old? I don’t hear a rod when actually driving, then again I haven’t really rev it high just waiting to change out the oil. Any Ideas?

i dont think its rod knock… it sounds like its your valves… if it were rod knock it would always do it at start up… i believe its your valves bacause you say it only does it when the car sits over night… and if it were rod knock you wouldnt be able to rev high at all without hearing the LOUD knock

I get a slight “knock” when the engine is below -0 celcius every morning. Seems good now that the weather is warmed up. 350,000km’s on a stock block I dont really blame it, yet it hits rev limiter every day for the past 1.5yrs and still runs like a champ.

i also think it’s just your valves. any engine will make a knocking sound as soon as its started up considering theres no oil flowing through it yet.

btw how long have you had the 30w in?