Hey guys. I have a 2015 Rdx. 10,xxx miles on it now. I've noticed for a little while now when the engines cold, it has, what to me, sounds like a possible knock. At idle it sounds perfect. But when you give it a little gas it starts to clatter/what sounds like a possible light knock around 1500 rpm. The thing doesn't get beaten on when it's cold. Always fully warmed up before I take it to Anything past 3500 rpm. I drive it as gently as possible until it's up to temp as I do with all of my vehicles. Cars on its third oil change. Pennzoil platinum 0/20 or 5/20. Bosh distance plus filter on it. I should add that when it's fully up to temp it's silent and sounds great. I'm just wondering if anybody else has had or has anything like this going on? When I change the oil I noticed the oil pressure light takes around 5 seconds to go out. Always goes out within a second or less any other time. I know after an oil change there's a little bit of a dry start. But is five seconds too much? Is there and underlying issue here that might be raising its ugly head? The reason I say possible knock is because it's fast. Not half engine speed like valve train noise is. Maybe even piston slap when the motors cold? I dunno. When she's hot she sounds perfect. Is this normal or something I should be concerned with? Thanks in advance.
Chris

 

I have a knock (light tapping) on startups all the time on our 2016 RDX. I just attribute it to taking a bit for the oil to get through the oil filter (2400 miles and original oil filter). It may be that your filter is too dense and thus it takes a while for the oil to pass through it.

 

I should add that it only does it when it's cold out. If the outside temp is above like 55 it doesn't do it. I'm leaning more so on the side that it's just a normal characteristic but I just wanna make sure

 

I've noticed with most of the Honda-powered vehicles I've owned that when cold, you get a ton of injector noise and that the motor will make odd sounds as the various components warm up. It's not really an oil-flow issue, but rather just "normal" sounds as things get up towards operating temperature. The injectors and intake does do different things when cold vs when warmed up, so that may be part of the sound you're hearing. I doubt it's a "knock" from the lower end, and likely an intake-level noise.

andy