Sludge in Oil Strainer Options

[mtc911]

I’ve changed a lot of oil over the years but never seen this sticky oily smelling “sludge” I guess? Oil is not that old. Should I be worried? What causes it? The car doesn’t run hot. Good news is nothing metallic.

[wonkipop]

i've seen this in a newish toyota and a subaru that the mechanic who works on my cars does regular servicing on. he believes its a growing concern and the theory is increasing stop start driving with engine never really reaching operating termps for long enough.
the covid lock down seemed like it might have had something to do with it as neither of the cars which he regularly worked on seemed to have this before.

too much cold running? not sure. there are articles out there in the motoring press about it at the moment. there is a couple of theories on it. perhaps it has increased due to people not driving their cars as much as they did during the pandemic restrictions. or perhaps it is to do with how oils are being manufactured and from what base stock.

its bad and you should try and get a flush cleaner through the engine with the oil change.
it can block oil passages. you need to get it out. have you popped the valve covers to see what its like in there? often its all through the engine.

mechanics usually call this a varnish deposit i think.