Spark Plugs & Ignition Coils

Ignition coils don't need replacement. I normally get more than 200K, before they start to fail.

NGK, ND, even the Autolite iridium seem to last at least 100K miles. Drop the old plugs into the trunk in-case you get a failure.

 

Cheap plugs on Amazon are likely to be counterfeit, and sometimes the quality is such that an electrode or chunk of ceramic will fall into the cylinder and wreck your engine. Plugs from your dealer or a local brick-and-mortar job shop would be a better bet.

If a coil ain't broke, replacing it with some inexpensive one may just mean putting something worse in your car than is there now.

 

When is a good time to replace coils? I haven’t had any problems with them I just hit 120K so I’m going to do the spark plugs. Just wondering how long the coils are supposed to last.

 

While anything can fail, and that can happen any time, I don't think they're really expected to, on any kind of schedule. They are solid-state electronics and copper wire wound around a core.

 

My ignition coil issues usually presents itself as an intermittent miss that comes and goes. Most of the time it doesn't trip the CEL and it's usually gone when I try to find it. The one time it did trip the CEL, it was P0300 - pretty much useless; I knew I had a miss. 18 months later, it finally stopped firing, when the engine was hot. Let the engine cool down a bit and it was gone again. I swapped the 'bad coil' to another cylinder to verify which one was actually bad. A couple of weeks went by, it started missing again. I went straight for the suspected cylinder and that was it. Problem verified. The odometer is currently at 260K, on that truck - 5 old ignition coils and one new one. It would've been a lot easier, if it just out-right died on me - so I could find it.

You can decide how often you want to change them, but beware - you may be installing counterfeit parts.

Good Luck.......

 

FWIW...coils don't need to be changed for maintenance.
Some co-members are saying a 200K life on a Prius, and I could agree.
Some could say, they fail when they fail.
Yet "no loss" except money, if you decide to change the coils.

Sparkplugs... too many stories of counterfeit so buy with care.
Either NGK or Denso should be fine; what does your owner manual suggest?

But.... I would replace the spark plug wires instead of the coils as maintenance (11 years/ 115K mileage).
Heat can "breakdown" the rubber and carbon of a spark plug wire.

Enjoy your car
.

 

I don’t think there are traditional spark plug wires?

 

Sure there are, just not in a Prius.

 

Indeed. 10mm Magnecor leads from MSD electronic distributor to NGK BP6ES plugs on the sports car...

 

Bpr6es plugs would foul even though they look normal. Bpr5es was the replacement that solved that problem. That was on Kawasaki and Nissan. Which engine and what application are you running 5es plugs?

 

NGK BP6ES in a U20 engine with B-cam, four throat Mikuni-Solex 44PHH-2 induction, crank-fired MSD electronic ignition.

Tried Champion N7Y N8Y N9Y decades ago and never went back. Stopped throwing plugs at it.