What maintenance procedures are "feel good" but of dubious usefulness?

Over the years I have seen a lot of suggested maintenance practices described, across all types of vehicle forums (VW, Honda, Tacoma, etc). Many of these procedures appear in lists of things people have tried in order to solve a poor running condition (that never seems to be resolved by these procedures). Some that reliably come up are:

• Seafoam through the intake manifold...makes an impressive smoke show, but is there any evidence that it solves or prevents any issues? Can it create more problems than it solves?
• Cleaning the MAF sensor...seems plausible that this could help if you have a related DTC or run an oiled gauze air filter. MAF sensors are also delicate and this could cause damage. Any documented reports that this solved a problem?
• Oil/gas additives...any evidence that these prevent or solve problems, or are they merely something to spend your money on?
• Excessively short oil change intervals/expensive oil and filters...I'm aware of used oil analysis reports ($), but do all of these costs increase longevity enough to pay for themselves? I've never kept a car long enough to find out.
  
• Replacing parts before they fail...in some cases can prevent dangerous conditions or prevent much more costly repairs, but I saw a comment recently about replacing the fuel pump every 75k miles as preventive maintenance. I also had a neighbor who replaced his coil packs every time he changed his plugs. How is this cost effective?

For the record, these are all things that I have personally experimented with at one time or another. This was particularly true when I was single and childless, and had more time and money to play around with vehicle maintenance. Looking back, I can't think of a single instance in which slurping seafoam through a vacuum line, or spraying carb cleaner on the MAF sensor made things work better.

My goal isn't to convey any endorsement or disapproval of these practices, but rather to take an honest look at what can realistically be expected when trying some of these things. Let's try to keep that friendly perspective in mind.

Any thoughts?

 

Actually dubious or perceived as dubious?

Apparently transmission service is seen as dubious here on TW. People spend all kinds of money on designer lubricants and fastidious maintenance then look at the transmission and go, "it's a lifetime fluid...fuck it".

 

Actually dubious, I guess?

If someone's definition of "lifetime" aligns with Toyota's, then why should they go above and beyond on any maintenance? Might be worth knowing how Toyota defines lifetime before saying "fuck it".

 

I didn't mean for that to sound as harsh as it did. But the enigma surrounding transmission fluid change has always puzzled me. If you're a DIY'er and can tackle basic maintenance like oil changes, differential services, brake jobs then the occasional DAF on the transmission is not difficult. Yet people shy away from it.

I'm a clean fluid guy. I'm not obsessive about it. But I am attentive. Oil changes are at 5k intervals (per the manual), diff service every 30k. At 50k I did the brake and power steering fluids and at 55k I serviced the transmission and coolant system.

Some may find that excessive and/or dubious

 

Changing blinker fluid is dubious but it has to be done.

 

From your list in my personal opinion only two things are legit:

1. Clean MAF when receiving "lean" code. I bought Sienna which after few years developed a "lean" code on both banks. I was testing all possible vacuum leaks, but then I took out MAF and it was incredible dirty. Not because the air current filter problem, but from who knows if PO ever replaced it or maybe even drove without it. Sprayed Contact cleaner (do not touch these thin wires in the sensor) multiple times until all junk was out. Never had "lean" code again. Just to be sure I'm clear: cleaning MAF is not a maintenance item, it just dirty MAF can be a cause of the engine problem.

2. Replacing part before they fail. This applies to "Maintenance items". You don't want to wait with replacing LBJ until they fail. Or replacing a spark plug till no electrodes are left. Look at the maintenance schedule and this will list parts that need to be replaced or at least inspected. Other parts that are not "maintenance items" or parts you have no way to inspect will be replaced after they fail (or about to fail). But this scenario is just simply "shit happens". Like nobody is replacing a headlight bulb after 250 hours of use just because 250 hours is written on the box, right. If it burns, you put a new one (yes, sealed beam lamp in early Tacoma is a major PITA to replace).

I am the biggest enemy of all "magic fluids" or "additives" that suppose to fix the car. At best they are simple "snake oil" using "placebo effect", at worse they mask the real symptoms causing more damage on the longer run (oil or coolant additives that supposed to seal the leak).

"Excessively short oil change intervals" reminds me the real story of my friend who bought a "junk car" for 200 dollars (I don't remember exactly what car was that). The car run like a crap but moved so for 200 dollars was OK deal. Then my friend looked at the oil, and it was a milky sludge in there. So he changed the oil for brand new one, and 5 miles later the engine seized. Apparently the oil pump failed long time ago (oil pressure indicator was also bad) but the water in the oil when was heating up somehow made the sludge moving a little through the engine - enough to keep it running. The new oil did not work that way so the engine seized from luck of lubrication.

 

I can tell this will be a great discussion thread. Thinking back to a V6 car I bought a few years back that had 4 different kinds of spark plugs. I could almost hear the exchange. You have a fowled plug. Ok. I'll let you replace that one. LOL

 

Chris Fix has a video showing how to do this, I think. I saw another one from him today about changing the air in your tires from summer air to winter air as the seasons change. Good stuff.

 

nitrogen in the tires

 

I assume DAF = drain and fill, correct? (as opposed to drain and flush) There is definitely a good reason NOT to flush a transmission in some cases.

But it's not about a trans fluid change being "dificult". It's a cost/benefit thing.

The factory doesn't say don't ever change it, it says to check it routinely and replace IF necessary. If the fluid is still bright red, then it hasn't broken down from heat or gotten contaminated, so there isn't really a need to replace it.

If you *want* to change it even if it's still perfectly fine, go right ahead.

 

I run the AC at least once a month as a maintenance measure, even when I don't need it. That definitely feels good.

 

DAF = drain and fill

 

It literally feels like a nice cool breeze...

 

Who has changed the oil and dryer in their A/C compressor-system?

 

I run ac every day.

 

You asking as preventative maintenance? Or because of need, like it was emptied for some reason and then repaired and then charged again?
I've never heard of this being done as PM, so I don't know if you're being funny or not lol

 

As much as even I tout changing a timing belt on time for vehicles, it's probably more efficient to change them on age than mileage. Has anyone broke one younger than 10 years old, no matter the mileage? I'm on my third but they always looked like they had another 100K in them when they came out. Tensioners, another story.

 

I had to remove a compressor to change a clutch once, then decided the flush the system, change the dryer, and reinstall new oil. It worked like new when I was done. Then I learned there are some people who do that after 150,000 miles.

 

The question is a trick question... let me explain. If you have 1st gen Tacoma, any engine, any trans, they break down so little that normal maintenance IS preventive maintenance. If you open the hood every other time you fill the tank and just take a quick look... brake fluid OK, radiator overflow OK, quick oil dipstick and look for drips from radiator area and trans... This truck with normal maintenance will go 300k easy.

Some peeps replace lower ball joints regularly, not sure if this is a feel good measure or preventive maintenance. Never having had one let go driving and create a furrow in the asphalt I can't speak to how THAT feels ;-)

Now if we are talking other manufacturers... My 01 Ranger needs a new thermostat housing every 3 years... it is a plastic tri-lobed p.o.s. that seeps coolant no matter what you do. My 99 F150 5.4 needs at least one coil every winter. My 08 BMW X5 just needs to be replaced. My 1987 Nissan D21 4 cyl needs a cap and rotor every 2 years. After owning these from new, you figure it out when it is the same thing over and over, feel good, nope, that is just how it is.

 

It's a piece of mind thing. I'm on my 3rd set of ball joints (including originals). A hundred bucks or so every 5 or 6 years goes a long way to give me some piece of mind when you google "tacoma ball joint failure"... I've never had a BJ let go either. And I plan to keep that streak going as much as I can.