Parts for your 2020 Mitsubishi Asx-Oil cap

2020 Mitsubishi ASX oil cap — what it does and how to look after it

Yes, the 2020 Mitsubishi ASX does use an oil cap. Mitsubishi’s 2020 ASX Owner’s Manual (Maintenance – Engine oil) identifies an engine oil filler cap on the valve/rocker cover, and the 2.0L MIVEC (4B11-series) service literature likewise labels the engine oil filler cap as the refilling and sealing point for the crankcase. That makes the oil cap a relevant, fitted part on every 2020 ASX.

On this ASX, the oil cap seals the top of the engine where oil is added. Its job is simple but critical: keep engine oil in, keep dust and moisture out, and prevent unmetered air getting into the crankcase so the PCV system can do its thing properly. A healthy cap and gasket stop oil mist from weeping onto the rocker cover and cut down on those hot-oil smells under the bonnet after a run.

As part of routine servicing, it’s worth giving the cap a quick once-over. Wipe the area clean before removing it so grit doesn’t drop inside, add oil as required, and refit the cap hand-tight until it seats securely. No need to lean on it—over-tightening can damage the threads or distort the seal. If the cap’s O-ring or gasket is cracked, flattened, or hardened, replace the seal or the whole cap. Likewise, swap the cap if it’s warped, cross-threaded, or the symbol plate has come loose.

Common signs the cap needs attention include fresh oil mist around the filler neck, a light film of grime radiating from the cap, or a stubborn fit that never quite feels “home.” A missing or poorly sealing cap can lead to oil splatter under the bonnet and contamination inside the engine, so if it’s lost or broken, don’t keep driving—shut the engine down and sort a correct replacement designed for the ASX’s 2.0L MIVEC. Genuine or quality aftermarket caps that match the OE specification are fine.

• Check the cap at every oil change or any time the bonnet is up.
• Keep the sealing surface clean, replace the O-ring/seal if it’s tired.
• After refilling, start the engine and confirm there’s no seepage around the cap.

Mitsubishi technical references: 2020 ASX Owner’s Manual (Maintenance – Engine oil) and 4B11-series engine service manual illustrations identifying the engine oil filler cap.

FAQs

Where is the oil cap on a 2020 Mitsubishi ASX?
It sits on top of the engine’s valve cover under the bonnet, marked with the oil-can symbol. Facing the car, it’s typically on the upper side of the engine assembly for easy access.

You’ll spot it quickly once the plastic engine cover (if fitted) is visible. It’s the point used by technicians and owners to add engine oil during servicing.

Can the ASX be driven without the oil cap?
No. Driving without a cap can spray oil around the engine bay, draw dirt into the engine, and compromise crankcase ventilation. That risks damage and a big clean-up.

If the cap is missing or broken, switch off and arrange a proper replacement before continuing. It’s a cheap part that protects a very expensive one.

How often should the oil cap be replaced?
There’s no set replacement interval. Inspect it at every service and replace it if the cap is cracked, won’t seat securely, or the seal is perished.

If you see oil weeping or smell hot oil after a drive, check the cap and its O-ring first—it’s often the quickest fix.