Replace all ignition coils and spark plugs simultaneously? (1 Viewer)

[GTV]

IMO a good rule of thumb is to use long life (100k mile) plugs and replace them with every timing belt (90k). Replace the coils every other timing belt (180k).

 

[rexington14]

OE Toyota Denso coils last a long time. And they are expensive. Obviously replace them if you see they are cracked or discolored or otherwise causing issues.

Instead of replacing them as a preventative, last year I chose to "refurbish" my coils. There's a kit you can buy to replace the rubber boots, rubber seals and springs (see below after cleaning & installing new rubbers). Denso coil rebuild kit (part #671-8184).