Hi I'm new in the forum and registered especially for this question hope you can help me I have a Toyota corolla 2004 with 3zz Fe engine that owned for 3 years at the start I used Toyota oil 10w30 that it burns about 1.5 Lt every 5000 km and had to clean the oil screen every year to clean oil sludge that was formed because previous owner changed oil every 15000 km now I I used different oil type max life and Mobil 1 the only oil that stopped the burn is liqui moly 5w40 now the problem is liqui moly is fine oil and clean the sludge well causing the oil screen to get dirty only after 1 month of use can I use liqui moly engine flush to clean what's left or what can I do I don't want to harm the engine Thank you
What does it look like under the valve cover? Its possible most of your sludge is coming from that area and may need to be cleaned manually. I would begin by removing the valve cover to get a better idea of your your dealing with and doing an overnight piston soak through the spark plug holes.
Manually clean the head and drain back holes if necessary, remove the pan and clean it and the pickup screen then run a short oil change with cheap oil to flush any residual away. Post pictures and ask questions if you need help on how to do any of this. I would probably run Mobil 1 0w30, Castrol 0w40, or Euro Castrol 0w30 in this engine in your climate, you will probably be better served with an oil with a 3.5 min HTHS.