In a Toyota and Lexus hybrid the petrol engine does not run all the time, but it often stops and starts from cold. The plug gets short cycles instead of a long, hot run. A worn plug causes misfires, and the owner often takes that for a weak battery.
Symptoms of a worn plug
- Jerking just after the petrol engine joins in
- Uneven revs when stopped, once the petrol engine is already running
- Misfire codes on one cylinder
- Higher fuel use on a trip, where the engine runs longer
What we replace
We fit iridium plugs with the part number from that engine’s manual and we do not file the gap. If the spark fails on only one cylinder, we also check the coil. The factory interval can be long, but on nothing but short trips we inspect the plugs sooner.
Do not confuse it with the HV battery
A weak battery shows up as a loss of power under load and a hybrid system message. A plug jerks mainly while the petrol engine is running. So we separate the two faults first, rather than replacing the pack “just in case”.
Jerking when the engine joins in? We will check the plugs, the coils and the HV battery separately.
Visit Green Serwis in Krakow — we specialise in Toyota and Lexus hybrids.
Book a visitSummary
Regular diagnostics and careful use keep a hybrid free of surprises. If you have questions after reading — see our hybrid service or contact us.
