New Fluids & Plugs Necessary?


#1

Hi Folks, My wife has a 2008 Saturn VUE XE with about 120,000 miles. She keeps it in very good condition, especially the interior and exterior body. She has the oil changed about 4 times per year. She has purchased one set of tires (all 4) in addition to the originals. The problem: At last oil change and state inspection, the dealer/service people told her that she may need new brakes (OK, I accept that after 120K), and…" all new fluids AND new spark plugs." The car has not been hard to start nor has it been sluggish when asked to pass a semi on I-80. Supposedly, the Service people are checking the fluids at every oil change. I really have to question the “fluids and spark plugs” work. But I am NO expert at all and value the CAR TALK community for its advice. Is this a real concern or perhaps just a Service “make work” promotion? Please help!


#2

Do you have the vehicle’s Owner’s Manual?
If so, the maintenance schedule lists replacement of spark plugs at a specific interval–perhaps every 90k miles, or–at the most–every 120k miles.

Can you drive further with old plugs?
Sure you can, but your gas mileage will likely improve, as will your acceleration, if you replace the plugs.

Even though you think that the engine is not sluggish, I can guarantee that it will run better once those old plugs are replaced. When they finally become far too eroded to work properly, you will experience starting problems. Do you really want to push things to that limit?

As to the fluids, your maintenance schedule most likely also lists changing the coolant at a specific interval–perhaps every 90k miles or 8 years, whichever comes first. Translation=Your coolant is long overdue for changing, and the result can be rust/corrosion of the cooling system.

Whether the maintenance schedule lists changing the brake fluid and the transmission fluid or not, you are also long overdue for these services. Trans fluid should be changed every 3 years/30k miles in order to avoid transmission failure. If you have never changed the trans fluid, you have definitely shortened the life of the transmission, but you can limit the damage–somewhat–by changing the fluid now.

Brake fluid is hygroscopic, which means that it absorbs moisture from the air. This moisture dilutes the brake fluid and the result is reduced stopping ability on a long downgrade, and possible damage to brake parts. Change it now to limit future mechanical problems and safety problems.

…and please start to read and follow the maintenance schedule that should be sitting in your glove box!
If you don’t have an Owner’s Manual, this is a perfect illustration of why you need to get one.


#3

Check your owners manual and it will spell out when the plugs need to be changed, in addition to any other maintenance. 100K is usually the target to replace plugs. In addition to the plugs wearing out, they can also corrode and bind up with the head and you would never get them out later. Getting them out now will be less costly in the long run. If the automatic transmission fluid has not been changed, it is long over due. Do not get a flush, a simple drain and filter clean/replace is recommended.


#4

Spark Plugs, Transmission fluid, Radiator coolant, Brake fluid, Power steering fluid, These things all need to be changed about 20,000 miles ago…Do it now or pay dearly later…


#5

My dentist wants me to come in for regular cleaning and exams. Since my teeth don’t hurt and seem to work fine I can’t see any reason to do this. I brush them regularly and they look ok so I don’t know if I really need to see him.

OK seriously though, spark plugs were due at 100K, plan on replacing the wires at the same time.

I believe coolant service is due at 5 years or 100K miles.

In my opinion transmission fluid should have been serviced at least twice by now.

Brake fluid should have been replaced at the time of brake pad or shoe service.

Power steering has no set interval but is replaced based on condition.

If none of these things have been done in 120,000 miles your wife’s car is grossly “undermaintained.”


#6
My dentist wants me to come in for regular cleaning and exams. Since my teeth don't hurt and seem to work fine I can't see any reason to do this. I brush them regularly and they look ok so I don't know if I really need to see him.

I know. Whenever I get my dental cleaning they tell me how important flossing is. I tell the hygienist that if I took perfect care of my teeth I would not need her to clean them twice a year.


#7

Yep to above comments. Might be easier to just trade than bring up a 6 year old 120K neglected car up to spec again.


#8

My dentist wants me to come in for regular cleaning and exams. Since my teeth don’t hurt and seem to work fine I can’t see any reason to do this. I brush them regularly and they look ok so I don’t know if I really need to see him.

You will probably get to the point where you will drop your teeth off at the dentist in the morning before work and pick them up in the afternoon after work.


#9

The old plugs may fire just fine with no loss of power or fuel efficiency, but they need higher voltage and put more stress on the rest of the ignition system.
A new set of plugs will seem inexpensive if you end up with a coil or ignition module that fails prematurely.


#10

@Triedaq‌ “You will probably get to the point where you will drop your teeth off at the dentist in the morning before work and pick them up in the afternoon after work.”

It’s not that bad. I had normal dental care growing up. But from the time I was 18 to my current 44 I visit the dentist every 4 years. In that time I have had one old filling repaired and a wisdom tooth pulled out. I haven’t had a cavity in 28 years. At my last checkup my dentist reminded me that I’m getting older, things may start to happen and I should come in every 2 years instead of 4.

My wife goes to the dentist every 6 months and it seems like every other checkup they find something wrong that needs to be fixed. It’s just like going to a mechanic.


#11

When a plug starts to misfire, that energy has to go somewhere and that somewhere is across the turns of wire in the coil. That in turn damages the coil. You need to change the plugs before they start to misfire and cause the hard starting and poor mileage.

One of the things in the coolant that protects your engine is a sacrificial metal. It absorbs any free oxygen through corrosion, protecting the metal in the engine. Once it is used up, then any free oxygen that gets into the system will start corroding the engine itself. If the coolant is the slightest bit cloudy, you engine is starting to be eaten away.

Transmission fluid is an oil, and like any other oil, it breaks down with heat. When it breaks down, then it stops protecting the transmission. If your ATF is anything but a bright red, you need to get it changed, drain, change filter, refill. You can have a fluid exchange done as long as all the ATF in the sump, or pan, is drained and the filter changed first. A flush by itself will not help and may do some damage.

Brake fluid absorbs water which lowers its boiling point. That could cause you to loose your brakes on a long down hill. It also increases the aging of the rubber components. It should be flushed out when the brake pads are replaced.


#12

The bottom line is that you’re overdue for all the routine maintenance that you should be doing.
VDC posted an excellent list along with the reasons, as he usually does.

The dealer is being honest. A tip of the hat to the dealer. If you feel comfortable there, I see no reason not to use the dealer. If he were going to screw you your list would be a lot different. You could probably save a lot of cash by finding a reputable independent shop, but my belief is that if a shop is being honest and responsible, they’ve earned the business, and your risk is lower.

Kudos to the wife for taking care of the interior and exterior. Time now to begin taking care of all the stuff under the hood and chassis that you can’t see.

Sincere best,
TSM


#13

Spark plugs should be changed at the interval designated. Even if the car runs smoothly, the occasional misfire can make the car fail the emission test. I agree with VDC’s observations.

My 2007 Toyota is due for a coolant change next February, even though by that time it will only have about 45,000 miles on its Super Long Life Toyota coolant, I will change it. And the spark plugs will be changed based on elapsed time as well.


#14

I’ll go a little off topic

“My wife goes to the dentist every 6 months and it seems like every other checkup they find something wrong that needs to be fixed. It’s just like going to a mechanic.”

Not everybody is blessed with your good teeth

It’s possible your wife’s teeth are literally not as good as yours

My own teeth are so-so. I still have them all, but I need a deep cleaning a few times a year. I also grind my teeth at night, so I have to wear a night guard. By the time I figured out I need a night guard, I had already cracked some teeth. Not to mention that it would constantly wake me up, causing me to always be cranky the next morning, due to a lack of proper sleep. I also used to brush my teeth incorrectly, which caused me to brush right through the enamel.

My brother’s teeth are very soft . . . not enough calcium, apparently. That has led to some problems over the years. He also has to wear a night guard. But his gums are in better shape and he doesn’t need the deep cleaning


#15

@asemaster–Be glad that you have great teeth and had normal dental care growing up. I went to a dentist growing up that didn’t do a good job in that he didn’t grind out all the decay and would then slap in a temporary filling. When I was in high school, I finally went to another dentist who redid the work. I lost a molar and had to have a bridge. All went well until that dentist retired, I thought I had selected a good dentist, but it turns out that I made the same mistake twice. After a couple of problems, my wife suggested I get another opinion, which I did. I found out that I had all kinds of problems and was sent to different specialists–a periodontist, an endodontist, and finally an oral surgeon to remove a tooth that was too bad to be saved. I have great sympathy for people who trust a mechanic only to find out that his work is causing damage to the car.
I’ve also had problems with my feet. I used to run about 3 miles a day and then suddenly, while running, my foot hurt so badly that I had to stop and limp back to the dressing room. Itg turned out that I have a heel spur. I now have to wear orthodics in both shoes and my 3 mile daily run has been reduced to a 3 mile daily fitness walk.
I talked to my physician about my problems and he diagnosed my conditions as “hoof and mouth disease”.


#16

This is taking a turn elsewhere, and I get why. However, the discussion is only a day old, and though many OPs don’t come back to comment, I don’t think it would be fair for him to come back and try to post, find it closed, and then be unable to participate in his own thread.


#17

Ignoring required maintenance can cost you a lot more in the long run. Do what the manufacturer told you to do.


#18

I used to own a 2000 Ford Windstar minivan. I purchased the minivan from a small town dealer and took the Windstar in for its 30,000 mile servicing. The dealer changed the transmission fluid which was only required by the manual for “severe” service. I didn’t think that I fell under that category and was a little irritated by the dealer for performing this service. I also kicked myself for not being more diligent in going over what needed to be done to the Windstar. However, a couple of months later, I learned that the Windstar did have transmission problems and was glad that the dealer had done a fluid and filter change on the transmission. I faithfully had the fluid changed every 30,000 miles and had no problems in the time I owned the Windstar.
I also used to own 2006 Chevrolet Uplander minivan. I decided to replace the Dexcool antifreeze long before the interval specified in the manual. I had the Dexcool flushed out and regular antifreeze installed. My son now has the Uplander. It now has over 125,000 miles with no cooling system problems. The Uplander has had not transmission problems which may be because a schedule has been followed on replacing the transmission fluid.


#19

My point with the dentist example was that even though things seem to be just fine they may not be. And just because one set of teeth can go 25 years without a cavity that doesn’t mean another set can. The same can be said for cars.

As for teeth, I was talking with a cousin who has the same good luck with her teeth, while others in our family do not. We came to the conclusion that our good teeth are the result of hating milk and stopping drinking it at an early age.


#20

My Rav4 just made 78,000 miles and 5 years old. My plan has been to phase all the required maintenance across the year, doing one thing a month to bring it up to date. I’ve done the brake fluid change earlier this year, transmission fluid change just this month, brakes next month, and coolant change this fall. I’ll also get a set of plugs in her before the year is out. If the single cost of doing everything at once is too pricey, space it out a bit with the most critical item or items first.