How many miles should spark plugs last?
- Thread starter shew01
- Start date
Ernie Vitucci
Well-known member
Good Morning all...The other day I realized that my 2016 Jeep Patroit owner's manual suggests changing the plugs at 60,000 miles. I have 74,000 miles...so we changed the plugs...the difference in performance was actually surprising. SO I changed the plugs in my 1931 Model A Tudor which has had the same plugs for the 19 years that I have had the car. The same thing happened...much improved performance. I had not noticed a loss of preformance in either machine...I suggest changing the plugs...Just my personal experience...Ernie in Arizona
Reading some of the comments posted here makes getting a Carfax report even more important.
If your driving a modern car that has not had its plugs changed in over 100,000 miles and you think it runs like new? What else have you not had serviced? What does the manufacture recommend for service? Do you care?
I stand by my comment. “Model A Ford owners are known to be cheap”. Shade tree mechanics don’t always fix things correctly.
Our cars were always well maintained. When it was time to sell, condition was never a question. Mechanically, they were 100%. 60 years, never broken down on the side of the road.
To each his own.
If your driving a modern car that has not had its plugs changed in over 100,000 miles and you think it runs like new? What else have you not had serviced? What does the manufacture recommend for service? Do you care?
I stand by my comment. “Model A Ford owners are known to be cheap”. Shade tree mechanics don’t always fix things correctly.
Our cars were always well maintained. When it was time to sell, condition was never a question. Mechanically, they were 100%. 60 years, never broken down on the side of the road.
To each his own.
shew01
Well-known member
Good idea. #4 was the culprit. Now, I’ll change the rest of them.
For what it’s worth, I’m moving from Motorcraft TT10 plugs to Champion 518 (W18) plugs. The electrodes on the new plugs are much stiffer (to the point this at the plugs want to bend my gapping tool). I don’t know what other differences are likely, but it appears that I am past the miss.
Sent from my iPhone using Tapatalk
nkaminar
Well-known member
Some plugs last longer than others. Some plugs perform better than others. I now have Champion W16Y plugs in my Model A and they are performing better and lasting longer than plugs I have used in the past.
RotorWrench in Post #19 said that the spark plug tester he used for airplanes put 120 psi on the plugs. Higher pressure air is more resistant to electrical current than lower pressure air. So a plug that is operating OK on top of the head may not work OK when under the pressure of compression.
RotorWrench in Post #19 said that the spark plug tester he used for airplanes put 120 psi on the plugs. Higher pressure air is more resistant to electrical current than lower pressure air. So a plug that is operating OK on top of the head may not work OK when under the pressure of compression.
David in San Antonio
Well-known member
(Warning: tangent ahead) Gary in WA - Those little compressed air-powered abrasive spark plug cleaners brought me back to 1974. I was working as a mechanic’s helper at a Kawasaki motorcycle dealer in an era when they had a full range of bikes, both street and dirt, but only one had a four stroke engine, the rest having two strokes. These were relatively advanced in that you didn’t mix the oil into the gasoline, every model had “automatic oil injection”, a fancy term for a little plunger pump run off the crank. Motorcycle sales were booming, meaning most of the customers were buying their very first bike, and many were unfamiliar or uncomfortable with the necessary practice of keeping the revs high so the plug (or plugs) wouldn’t foul. So every Monday we got lots of customers bringing in their bikes, baffled about what happened to the pep of their brand new toy. Pull the plug(s) and they were, predictably, black with oil. A few seconds in the plug cleaner made them shiny again, blow out any remaining abrasive grit, check the gap, and they were on their way again. Perhaps the sales guy instructed them to wring it out? I don’t know. I don’t know how other shops operated, but that plug cleaner was used so often we had it mounted to the wall like the pencil sharpener was in elementary school. One pretty big guy brought in his little 125cc scrambler. The plug was fine but the fiber surfaces of the multi-plate clutch were almost completely gone. Turned out he knew all about keeping the revs up, but he was reluctant to downshift. So he just kept the throttle pinned and slipped the clutch. A lot. Fixed under warranty.
Last edited:
Y-Blockhead
Well-known member
Last edited:
shew01
Well-known member
Do these plug cleaners essentially “sand blast” the plugs? How great of a risk is it to get abrasive residue in the engine?
Sent from my iPhone using Tapatalk
shew01
Well-known member
The reason I was reluctant to change plugs was that I was looking for the culprit that caused the issue in the first place. I was thinking replacing the plugs could mask some other problem that I had not found yet.
Sent from my iPhone using Tapatalk
Last edited:
David in San Antonio
Well-known member
Shew 01 - Yes, they are sand blasters. Maybe not sand but your choice of medium. We followed up the blasting by blowing the plug by unsnapping the airline that ran the cleaner and blew out any remaining media from the plug. Took all of 60 seconds. That will be $5.04 including tax.
Gary WA
Well-known member
Yes blow out good no problem. on all my 3X plugs i take apart, and tape off porcelain etc not to glass bead certain areas of plug and use my glass bead.
shew01
Well-known member
Very interesting. Thanks for sharing. If I applied the 10,000 mile rule to Champion 3X plugs, that would get pricy. I think I’ll stay with the Champion 518s (W18s).
Sent from my iPhone using Tapatalk
Big hammer
Well-known member
There’s other plugs less expensive and run just as good or better than the 3X’s
pwalk6270@gmail.com
Junior Member
Check the distributor cam or replace with a new one also check the distributor shaft bushings for wear