Longest you’ve seen someone go on a set of spark plugs

Joined
Dec 28, 2014
Messages
2,852
For me it was 189,000 miles, original plugs on a Jeep Liberty with the 3.7 in it. At that point they had developed a misfire (coil) and we pulled the plug and it was original (gap was huge). The funny part is; those plugs on that style engine are so easy to change, you literally could change those things in under an hour if you put a little effort into it.

On the flip side, I usually see plugs coming out at 100,000-120,000 and these plugs look like they’re almost brand new.

I‘m at 62,000 miles on my V6 Avalon and I’m dreading changing the plugs at 100,000...intake has to come off, cowl, lots of fragile little vacuum hoses stuck on very fragile plastic nipples. Not looking forward to it at all.

What‘s the highest you’ve seen/gone on a set of spark plugs?
 
I just changed the plugs and coils on my '03 Civic EX for the first time (yeah, 18 years!). The original Densos had a little over 158,000 miles on them. I'm the original owner of the car. The originals didn't look horrible either. I replaced them with NGK Iridium IX's.
 
I think the longest I've ran a single set of plugs (Bosch Platinum) is about 125K miles. They weren't missing when I removed them I just felt guilty they'd been in the car so long.
 
I put 168K on the factory plugs in my ‘97 Ford F-150 5.4L engine. Only changed them out because I figured it was time. Truck still run the same after new plugs were installed. 15mpg before and after plug change. 👍
 
180,000 miles on the factory AC Delco Iridiums. They came out of the aluminum heads with a mighty puckering squeak. The threads were a bit corroded. The Iridium tips still had life in them. It ran well before the plug change and just as well after the plug change.
 
Last edited:
"...#11&12 looked the worst by a mile and had the Roundel printed on the ceramic. The rest did not."

Are those plugs hard to reach on that engine/application?

BIL's 1970 Dodge Charger had the 383. The sparkypoo next to the steering gear was @76K when I changed it.
 
209,000 my dad took the original plugs in his 2004 Camry to that because it never showed signs of needing replaced and he isn’t one to spend money if he doesn’t have too. Then they started slightly missing so we replaced them it now has 279,000 on the vehicle with the NGK plugs still going strong.
 
I've seen others whom I know put on over 200K miles on the OE plugs and the engine ran fine. Would the engine have run better with a fresh set of plugs? IDK but, I would think it would. We've put on over 160K-170K miles on OE plugs and again, the engines ran fine.
 
209,000 my dad took the original plugs in his 2004 Camry to that because it never showed signs of needing replaced and he isn’t one to spend money if he doesn’t have too. Then they started slightly missing so we replaced them it now has 279,000 on the vehicle with the NGK plugs still going strong.
209,000?? Winner winner, chicken dinner!

That’s the most I’ve ever heard of. That the 4 cylinder Camry?
 
After reading through so many posts, I’m wondering if perhaps I can stretch my plugs out to around 120,000 without issue and then take that intake manifold out, maybe replace the rear coils with new OE coils and maybe do the rear valve cover gasket. Because I don’t want to have to go back in there for a misfire from a coil or a leaking valve cover.
 
I had a Ford Winstar come into the dealership that had a CEL on. It had 220K miles on the original plugs and the tech next to me replaced the plugs before trying to fix the CEL. Turns out the CEL was on because of a vacuum leak.
 
Back
Top