My car manual says to replace spark plug after 130k miles, but I'm now at 210k and have no issues. Should I replace them anyway?

Can't you replace them yourself much cheaper? Or is that not possible with modern cars?

$400 for sparkplugs?! There really is a tax on stupid. Ya ever thought about spending an afternoon watching a YouTube vud showing you how to change em yourself? Buy a few basic tools and plugs and get it done for less than $100.

Can't you just look online?

You should definitely replace them.

Worn plugs stress out the ignition coils, which could cost you more money.

bangdingow wrote:

$400 for sparkplugs?! There really is a tax on stupid. Ya ever thought about spending an afternoon watching a YouTube vud showing you how to change em yourself? Buy a few basic tools and plugs and get it done for less than $100.

No idea about this car, but some require specialized tools. What would the cost of those tools ? What is the cost in terms of your time? If it is going to take me 3 hours to do it then maybe paying someone else is a way better deal.

The only way to know for certain whether they need to be replaced is to remove and inspect them, at which point one might as well just put new plugs in. Parts cost should be around $30 if you can do this yourself and have the proper tools including metric wrench set, spark plug socket, socket extension, and torque wrench.

This isn't a difficult job, but there are horror stories of novice mechanics cross threading aluminum heads which can be a very expensive mistake. If you (or a trustworthy friend) are not modestly skilled, it might be better to take it to a mechanic. $400 seems absurdly high for this sort of thing, so if that's a real quote you've received, I'd suggest shopping around.

Yes, replace them. I replaced the long overdue spark plugs on my beater '96 Subaru Legacy at 212K miles, and the gap was huge, way out of spec. It ran noticeably better/like new after the swap.

You should be able to DIY the spark plug change yourself after watching a YouTube video. A quick search there shows pretty short videos, which suggests it's an easy job, not a $400 job.

“Stress the ignition coils”?

Seriously! That’s just not true. Coils just provide high voltage to the spark plugs to create a spark.

On the other hand, a bad coil can reduce the spark thus causing poor performance.

With respect to the ops question, with that much mileage get the plugs changed. If done correctly it can’t hurt. You may notice a slight improvement in performance. If you do it yourself make sure to check spark plug gap.

I had a God (Thor as a matter of fact, he turns out to be a commie!) saying I should replace my wife after that kind of mileage. It worked out well.

cappy wrote:

You should definitely replace them.

Worn plugs stress out the ignition coils, which could cost you more money.

That's a good one! OP, you should replace the plugs ... your horn will honk louder and your headlights will be brighter as a result!

Letting the days go by. wrote:

If you do it yourself make sure to check spark plug gap.

My understanding is that checking and adjusting the gap on new spark plugs was a thing of the past (60s - 80s era cars) that doesn't need to be done any more. Don't they come properly set with the appropriate gap now?

If its "only" $400, I would do it. Or if you are a diy-er, diy it, but on some cars, its complicated. The intake manifold comes off in some cases. Or crazy wrench extensions are needed. And break a plug or get debris in the hole...

On my car, shop time is 1.8h, thats about $180-200 plus parts Plugs, wires (?), coil packs (?). Some are far more.

At that mileage is take the car to a mechanic I trust to take a look over the car and suggest preventative maintenance.

I pay off my cars and drive them until they cost too much to replace parts. My last car was a 2008 Mazda 3 that I drove until it needed a new transmission that would cost more than the car is worth.

Make sure to change fluids on a schedule and not just oil. Transmission fluid is important. If it is stick listen for failing bearings. My current 2011 Subaru just needed a $1200 transmission but the car still drives like new so I made the investment.

Don't spark plugs come with the right gap now? wrote:

Letting the days go by. wrote:

If you do it yourself make sure to check spark plug gap.

My understanding is that checking and adjusting the gap on new spark plugs was a thing of the past (60s - 80s era cars) that doesn't need to be done any more. Don't they come properly set with the appropriate gap now?

You are correct. The gap is supposedly set correctly at the factory. It is a good idea to check it though. I just changed plugs in a friends 2007 4runner, 370,000 miles, and one of the six plugs was way off. You never know unless you check and bad gap can cause problems.

The car was intermittently throwing CEL. Determined that one of the coil on plugs was occasionally failing. It was located near the exhaust manifold/tail pipe and was probably heat stressed more than the other coils. I moved it to a different location just to make sure the problem followed the coil. Saved my friend about $700 by troubleshooting ourselves.

Yes replace now. You can get away with going on way over the recommended mileage as you have but eventually will catch up and lead to other problems in the car because you have to remember that everything is connected.

oldschoollrc wrote:

Can't you replace them yourself much cheaper? Or is that not possible with modern cars?

I was going to say this. Unless this some specialty car which it isn't he should be able to do it himself for like a 10th of the price. Of course that may require a level of handiness beyond his skill.

I would recommend doing it if the car has that many miles. Not something I'd say you need to do tomorrow but I would do it before too long. Better to keep the car going in the long run.

Yes, seems like a standard thing to do at that point.

Maybe that $400 quote included more service line changing a bent as well.

As they have things open in the engine, replace everything.

Star wrote:

Yes, seems like a standard thing to do at that point.

Maybe that $400 quote included more service line changing a bent as well.

As they have things open in the engine, replace everything.

Replace everything? WTF are you talking about? Cattlelytic conventers and Johnson bearings are just a given replacement parts at that mileage of course. Do you suggest that he should replace his dehydrated dihydrogen monoxide silica infused scrapers?

Just get yourself a crescent allen and fix your spark tubes right up.