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Common problems

Toyota VVT-i and Valvematic engines: common issues and fixes

VVT-i is in almost every Toyota petrol engine on Kenyan roads — the 1NZ-FE in the Vitz, Axio, Fielder and Probox, the 2ZR and 3ZR in the Premio, Wish, Noah and Harrier, and many more. The system itself is very reliable. When it does give trouble, the cause is almost always old or dirty oil.

Toyota 1NZ-FE VVT-i engine in an engine bay

Photo: Tennen-Gas · CC BY-SA 3.0, Wikimedia Commons

What VVT-i does

VVT-i (variable valve timing with intelligence) adjusts when the valves open, so the engine is both economical and strong. It works on engine oil pressure, through an oil control valve and a small filter screen — which is why the oil’s condition matters so much.

The common issues

  • A check-engine light with camshaft timing codes (such as P0011, P0012 or P0014): usually a sticking oil control valve or a filter screen blocked by sludge.
  • Rough idle, hesitation or poor fuel economy, for the same reason.
  • A rattle for a second or two on a cold start on some engines: a worn VVT-i gear (cam phaser). Not an emergency, but get it checked.
  • Valvematic engines (2ZR-FAE, 3ZR-FAE) add an electric motor that varies valve lift. A failing Valvematic actuator or controller brings a warning light and poor running.

Oil-burning engines to watch

Some 2.4-litre 2AZ-FE engines — in the RAV4 (XA30), Vanguard and Harrier (XU30) — are known to burn oil as they age. Check the oil level on the dipstick before you buy, and look for blue smoke when the engine is revved after idling.

How to prevent it

Change the oil and filter on time — around every 5,000 km on mineral oil, or as the manual says for synthetic — use the grade in the manual, and don’t stretch the interval if you drive in dust or heavy traffic. A VVT-i engine that has had clean oil all its life is one of the toughest engines you can buy.

What to check before you buy

  1. No check-engine light — and ask a mechanic to scan for stored codes.
  2. Start it cold and listen for a rattle in the first seconds.
  3. Check the oil level, and look under the oil cap for black sludge.
  4. Rev it after idling: there should be no blue smoke.
  5. Service records showing regular oil changes.

Models this applies to

Frequently asked questions

Is VVT-i a problem engine?

No. VVT-i is one of the most dependable engine technologies around. Problems almost always mean the oil hasn’t been changed often enough.

What causes a VVT-i check-engine light?

Most often a sticking oil control valve or a blocked VVT filter screen caused by old, dirty oil. A mechanic can clean or replace the valve; changing the oil on time prevents it.

Do Toyota 2.4 engines burn oil?

Some 2AZ-FE 2.4-litre engines (RAV4 XA30, Vanguard, older Harrier) burn oil as they age. Check the oil level before buying and keep an eye on it afterwards.

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