Hello odd question and I feel rather silly after doing this. I recently did a liqui molly pro line engine flush in my civic. What I did was dump my existing oil, put in cheap synthetic with the liqui molly, dumped that and re filled with good castrol synthetic. Now my question is this. I have ran a mobile 1 filter good for 20,000 for the last 3 thousand miles and didn't think to change it as it's brand new. Beings I didn't take it off at all after running the molly, would it leave enough in the system to do any harm? I wouldn't think so but I wanted peace of mind. Thanks

 

I believe the engine flush is a solvent. The filter will hold some solvent so it will have an effect on the oil. It will be quite diluted but will have some impact.

How much of the Synthetic do you have left? It's kind of depressing being Synthetic is more expensive oil but I'd say for my own personal comfort, I would want to drain off 2 liters (of the 3.3 mine holds) and refill. At that point I'd feel the solvent affected oil has been diluted enough for me.

Being you dropped a few bones to put in fresh oil just for an engine cleaner, maybe money isn't as much concern. If that's the case, then drain completely and refill without worrying about the filter, it's been flushed with the new oil and the solvent is so diluted now it won't have any significant impact on fresh oil the little that is in the filter.

 

I have about 1.5qt left, drove the car to go to the store earlier and it felt fine, very good actually. I still will probably drain and replace what I can with what I have. Castrol edge isn't the cheapest.

 

It drained enough that I figured most had gotten out as I put a little over 3.5 qts in. I think it takes 3.5 -3.75 it's a d16y7

 

It's probably just fine, I'm just paranoid like that. Maybe don't run the oil to full duration and do it a thousand or two early.

On rebuild mine takes 4 liters, but oil change is 3.3 liter so the head holds roughly 0.7 liters. I suspect if I didn't change the filter it would only need 3.1 or 3.2 liters. So really, you only have close to a liter of tainted oil being diluted with 3 liters good overall. That's usually fine as per the lube shops running their "engine flushes".

Being you are using full synthetic, it's even better oil so probably less impacted than conventional with it's additive packages.

 

Haha I'm paranoid like that as well. I dumped 1.5 and refilled this morning before work for peace of mind. Probably over thought it to begin with. Oil feels fine.