Long term maintainance

OK so I’ve decided to keep my 2014 TAH with 91k miles on it.
No problems evident. I am wondering about long-term maintenance items.
I don’t especially trust the manufacturer on this.
So, should I change the spark plugs, or the fuel filter,
or something else people don’t usually do?

OK , I will bite . What is a TAH ?

Toyota Avalon Hybrid.

Changing spark plugs at this point could not hurt. Same for a transmission fluid change.

Really, any fluid Toyota does not recommend ever changing is a candidate for change.


I figured it out by looking at the top of the post . But this is an example of not concidering that some people might not know what some shortcuts mean.

Actually someone who has been a member here for several years should have a basic idea of maintenance.

I would have bought a 6 yr newer car with fewer miles.

Things that will cost you money later if you don’t do them:

Engine oil. Every 100 hours or 200-300 for synthetic oil.

Transmission fluid (the Prius has an electric motor transmission. Don’t know about TAH). Every 700 hours. Do 2 or 3 times a in a short period to make up for past neglect. You only change about 1/3 of it at a time. Drop the pan and clean the sediment the first time.

Rust prevention. Keep it washed and/or garaged. This is a big one if you have road salt. Inspect and paint hard to reach places like under the bumper covers and the strut mounts on top of the struts.

Inspect engine mounts before they get too loose and let the engine move too much and break the exhaust joint.

Replace exhaust bolts with stainless with anti seize on threads.

Timing belt if equipped. Water pump. Non interference engine, but can save you from a break down.

Grease or replace bearings on belt drive accessories. For cars that are 20+ years old or sooner if a particular thing is know to fail.

Install some heavy sheet metal under the front bumper cover going back to the sub frame and fabricate mounts up to the bumper. This should save the front end from someone pulling up to far over a parking block.

Lubricate window tracks to reduce stress on the window regulator.

Flush brake fluid after 10 years and use grease on the brake bleeders so they don’t get stuck in the future. Flush the coolant too.

Paint brake lines with something like 2 coats of POR15 at the first sign of rust setting in. It will be a lot easier than replacing them later. Drop them down with the car on a lift and do it that way. You may need to do the same for fuel lines. But if the car is going to be junked in 20 to 25 years anyway it’s probably not worth it.

Buy a dashcam now before you get in an accident and have to explain that it’s not your fault.

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Vehicles go by miles or months , not hours .

Engine and inverter coolant are changed at 10 years/100,000 miles.
Spark plugs are replaced at 120,000 miles.
Just follow the maintenance schedule, the car will last 20 years but the batteries won’t.

Don’t know much about the TAH configuration, but replacing engine coolant more often than 10 years seems worthwhile. If you only want car to last 20 years though, 10 year intervals on the engine coolant is probably ok. I change spark plugs every 15-30 K miles, but I have the basic steel type. Yours are probably the fancy iridium type, and 120 K miles is probably ok w/those, tougher version. Worse case, if they fail sooner, you’ll know it right away b/c of misfire codes, and you can change them out at that point. Did you know the small spheres used to make the ball in ball point pens are made of an iridium alloy?

Your advice seems sound on the other items, particularly if willing to pony up some bucks to avoid break-downs on the road. But replacing the exhaust bolts proactively? I can’t imagine that would be better than just waiting until individual exhaust components or the entire system need to be replaced. It’s true it is time consuming (and expensive paying the hourly rate) to remove rusted exhaust bolts. But all that bolt removal work can be bypassed by just cutting the parts out with a saw or angle grinder when the parts need to be replaced.

That’s true. Just doing the bolts would be a waste. Removing whe whole thing and painting the flanges it and doing the bolts too is the way to go, if there is a paint that would hold up well enough. Probably better to just wait and have stainless flanges welded on all at once when the time comes. With me the stainless portions are fine. All the bolts and flanges are nearly gone.

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NUTS alert! This is a complete waste of time.


This vehicle is nearly ten years old, so it is too late to double-up with the maintenance. The second coolant replacement will be due at 150,000 miles.

Is there a paint that could hold up for years if the time was spent to do this?

The Aluminized exhaust pipe is a complete waste if the welds are not painted, since the welding process burns of the coating. You’re supposed to paint it at the welds, but it seems that people don’t. It just looks shiny like stainless but doesn’t last any longer than regular steel pipe since it will always rust through at the welds.

Check the rubber hoses to see if they are soft or collapsed. If so, replace them. Also check the bushings for wear. When I did all the maintenance on my 2005 Accord if replaced the flexible duct between the air box and the engine because it was too stiff to remove easily for maintenance. Check that too.

We’ve kept several vehicles over 300k miles by just following the maintenance schedule that’s outlined in the owners manual. It’s NOT that complicated. The only exception to the schedule is my 2014 Highlander where Toyota recommends 10k mile oil change interval…I do it every 5k miles.

I’d guess just following the car’s maintenance schedule would work for most of the items, but two that I would worry about on recent models are the spark plugs and the coolant. Waiting 100K to change out the spark plugs w/an aluminum cylinder head might increase the chance the cylinder head threads comes out w/the plugs. Unless there’s a major expense to the replace spark plugs, there’s more bang for the buck to replace them more frequently imo. Waiting 10 years to replace the engine coolant, same thing, it might work out ok, but replacing the coolant is usually a pretty simple & inexpensive job, not worth taking the risk of developing a cooling system related problem by waiting 10 years.

yes, I drain and fill coolant and flush (replace) brake fluid every 30k or 3 years.

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Can’t hurt to do these services a little early, Mom basically asks her mechanics what else they suggest and it’s worked out for the last 30yrs following their lead. There’s the schedule laid out in the manual but there’s no reason you can’t do these things earlier if you’re planning to own the car long term.

Never had that problem. Most plugs (Like NGK and Denso) have an anti-seize coating on them from the factory. I’ve heard of problems 2 decades ago with plugs seizing…but nothing since then. Have you?

No vehicle I’ve owned said to replace after 10 years. They all say 5. If newer vehicles are saying 10 years, then yes - I agree - replace at 5.

Toyota and Lexus have been using Super Long Life coolant since 2005, replace at 10 years/100,000 miles, then every 5 years/50,0000 miles thereafter.