Knock knock, who's there

[Pandabird]

Car has been sitting for over a month, parked front slightly uphill.
Battery was weak so I had to charge it up to crank
Oil on dipstick low but above minimum. Outside temp around 20 degrees Fahrenheit
Anyways I fire it up, idea to get it up to temp for an oil change and i hear what I don't want to hear.
knock knock knock. Not the freakishly loud kind, instinct said piston slap but it's in tune with the RPM and a steady beat.
I let her run with the hood open for a minute before I decided that no I will not and shut her off.
Sounds like it's coming from the passenger side, at least more audible on that side.
No warnings on the dash

Thing is I haven't ran it this cold yet so I can't be sure of what it is, I really wish it isn't Rod knock of all things. No symptoms before this.

What I want to do
*a full oil change the smartest way possible.
*check if problem persists.

I do not know what oil is in it, but I've bought a few gallons of suitable 5w30 and a matching filter.

Thing is I really want to get it up to temp too, just to drain it better and I want it on level ground for the oil change.


Idea is to pick a jug of random 5w30 (I got a bunch of those too), add a quart and let her warm up, then do the oil change.
Thoughts?

 

[rdezs]

I would add a quart of oil to it, and start it up. If it's piston slap it will go away as the engine warms.

If it's a rod bearing, it's not going to go away....

20° out and I assume you don't have a warm shop to roll it into.... Might as well start it up and find out. And when the sound goes away and the engines all warmed up, use a good quality 5W30 full synthetic like Mobil 1 or Valvoline. Either use the ACDelco filters or Wix.

 

[strutaeng]

Drain the oil into a clean container and look for the "forbidden glitter" floating around the oil.

Also, remove and cut open the oil filter and inspect the filter media.

Good luck.

 

[j91z28d1]

if it's sat for that long, if something hasn't changed just leave it till it warms up. you'll know forsure then.


on a side note, it's been proven pretty well that starting an engine on the old oil that's been sitting a long time, like over winter is harder on the car. as it sets in the engine, it turns, builds up. moisture and additives lose their properties and then you pump that thru the whole engine on top of it being a dry start. better to drain the old cold oil out before the first start. and then fire it up on fresh. even if you had to leave the drain pan under it over night.

cold oil is slower to run out, but it still will. if you have to fire it up to get into the shop, do that but just turn it off and change it. no need to let it warm up on old oil that's turned. It's being nit picky and it's more geared towards guys that have older air-cooled Porsches type cars sitting in a garage that only drive them 2 months out of a year but you get the idea.

 

[strutaeng]

1 month sitting should not be an issue. I've got a 04 project suburban that's been sitting for like 4 years now. I typically start it and let reach operating temperature about every month, or when I remember, lol. May be more like 6 weeks at times. I'm more concerned about the battery getting discharged from sitting.

Just a few months ago I actually changed the oil for the first time and it looked pretty normal.