I have 62,000 miles on my 09 Sport MT. How can you tell you need new spark plugs?

 

When it starts loosing gas mileage and or when it starts "missing" and running rough under load.

Spark plugs are cheap and easy to replace so you may be due with that mileage.

If it still runs good and fuel mileage hasn't dropped off just keep running the ones you have.

 

When your maintenance minder has sub item 4 the spark plugs should be changed.

Example your minder may read B 124. The 4 indicates the spark plugs should be changed. Just follow the maintenance minder and you should be OK.

I don't consider the Fit spark plugs to be easy to change when compared to the many vehicles I have owned.

Clifton

 

I was informed by the Honda dealer that at 105k miles is when the major service is done which is when the spark plugs are changed.

 

I had mine changed out at 60k but am currently at 103k on my 09 and am contemplating changing the Spark plugs.

Any recommendations? should I just go to Bernardi parts and order oem or does anyone here have positive experience with another set .


On a side note: this is not an easy procedure for this car. You can fanagle your hands in there are risk of dropping a socket or screw, or you can spend the 15-20 mins to pull the cowl cover, the wiper blades and wiper motor and metal cover beneath it to get the access you need.

Pain in the ass considering those plastic clips dont last forever and the cowl will eventually look like ass from removing for this and valve adjustments, coilovers and shock / spring replacements.

Think I'll be ordering some clips and bolts for bernardi in preparation for it.

 

Thank you all for your replies.

Early last year I noticed while accelerating in a higher gear from crawl-ish speeds, especially in warmer outside temperatures, the car will sort of hiccup a little, then go. I've gotten used to it, but I would love to get the smooth power back. As far as mileage, it's as outstanding as ever. I consistently got almost 42 mpg with every tankful, which includes 5 days of long commuting, filled with traffic every day.

I don't know if spark plugs are the culprit to the said trait, but I'll look more into it.

 

If it's missing/running rough it'll be throwing codes (check engine light). There are multiple things that could cause this.

The plugs would normally be changed before causing this behavior (at MM "4" around 105K miles as mentioned). They're iridium/platinum tipped and designed to last around 120K miles.

I've never experienced a car that the plugs got worn badly enough to cause missing/running rough/losing efficiency. If you never change them this would eventually happen.

 

Sounds like you're lugging the engine and it's knocking/retarding timing. Higher summer operating temperatures will make this worse as will aging. Try higher octane rated gas. Or downshift to accelerate.

 

if you are trying to accelerate in a high gear from low speed, choke yourself out, and then downshift and drive

that is a great way to kill the motor

 

Don't have my manual in front of me, but the plugs should last over 100,000 miles. My Tacoma has 140,000 miles with orig plugs. I will change them, when the engine starts to misfire, or the mileage drops. (Checked with Scan gauge)
Today's cars have a stronger spark, that will fire a plug with a big gap.
Back when cars had ignition points, instead of electronic ignition, plugs were changed at 12,000 miles. I found, that when we did a tune up on a car with plugs that were worn out so much the gap was much larger than spec, but the car was still firing the plugs ok, when we changed the plugs and gapped them to spec. (usually .035") the customer would come back in a few wks. and say his mileage went down. Smaller gap=smaller spark!

 

I'm with you on everything but waiting for it to misfire. This may cause coil-packs to fail prematurely. Of course on some V6 cars changing the plugs is better done during rebuild.