On higher mileage vehicles, an engine misfire may develop and/or the Check Engine Light may illuminate due to a failed ignition coil. It is not uncommon to replace all the coils when the first one fails in order to prevent return trips to the repair shop.Google+
Car Problem Reports
Lexus RX300 Ignition Coil May Fail After 100,000 Miles
Lexus RX300 Problem
Average Mileage: 105,708 mi (60,000 mi - 154,250 mi)
I had 3 coils fail within 9 months. At the point of the 3rd failure, I replaced all remaining coils. The front 3 are child's play to do yourself, a chimp with a screwdriver could do it. The rear 3, you'll wish you were a chimp due to the limited access. It can be done though, and without removing any other engine/intake parts. If this happens to you I recommend replacing all the coils, I never had a problem after that.
Visitor, 2002 Lexus RX300, 130,000 mi
replace coils every 5 months went in this time said two coils out and one valve is shot. basically im junking it. valve job is like 4000 and then what next the engine, Forget it. 3.0 motor sucks.
Visitor, 1999 Lexus RX300, 60,000 mi
Bought this 1999 Lexus 300 rx used with 30,000 miles on it. 2 ignition coils went out at 35,000 and now at 60,000 2 more have gone out. Not sure why we keep having to replace ignition coils every year but so far this hasn't been a good buy.
Visitor, 2000 Lexus RX300, 154,250 mi
Driving down the freeway and engine got loud (sounded like a putt-putt car), check engine light started flashing. Engine still had power so I kept driving. Shop found 3 cylinders were missing timing, replaced one bad ignition coil - cost $370.
Visitor, 1999 Lexus RX300, 85,000 mi
Car felt odd then the coil went out and couldn't even start the car. After getting it fixed, everything was right and felt normal.
Visitor, 2000 Lexus RX300
Check engine light came on and went off 3-4 times. Diagnostic check found coil pack needed to be replaced. No problem since coil pack was replaced.