Subaru 100,000 mile tune up

I have a 2002 Subaru Outback that recently rolled over 100,000 miles. I decided to look into getting a tune up for the car and was told by my garage that all they recommend is to change the plugs/wires and to clean the throttle plate. However they want around $500 to do this, so I’ve decided to just change the plugs/wires myself to save some money. I have done this type of maintenance before, but not on a modern vehicle (last one was a 88 Toyota pickup).

How difficult is this maintenance on the Subaru Outback? Is the Haynes repair manual for the Outback recommended and accurate? Will I need any special tools? I already have most of the wrenches and other tools that I think would be needed.

Lastly, is cleaning the throttle plate something that REALLY needs to be done?

p.s. I’ve already had the timing belt replaced, so that doesn’t need to be done.


apologies in advance for any typos (I’m in a hurry)

The cleaning of a throttle plate is not Subaru recommended.

Here is the manual available online>>>

You did not tell us about the car’s prior maintenance history, so this suggestion may not be valid, but in the interest of saving you money in the long run, I will suggest that you have the transmission fluid and filter changed. This procedure is supposed to be done every 30k.

If the trans fluid has never been changed, the transmission may have already suffered damage, but I would still recommend that you change the fluid unless it was done at 90k.

Also, the brake fluid on this car should be changed every 30k, so if that was not done at 90k, I urge you to flush the brake hydraulic system.

What is the maintenance history of this car?

I suggest you check the maintenance schedule that came with the car. It should be in the same package as the owner’s manual. The schedule will tell you what needs to be done and when. Following this schedule is the best advice I can give you.

If the transmission and differential fluids have never been changed it’s certainly time to change them. Brake fluid, too.

I use a Haynes manual in conjunction with the owner’s manual to help me maintain my Legacy and it seems to work well.

It’s good that the timing belt has been replaced. That’s a critical maintenance item that many people ignore because of the cost.

#1 There is nothing called a tune-up on a modern car. Modern cars come with an owner’s manual that list the MAINTENANCE that the manufacturer recommends. Failing to follow those recommendations will likely result in problems and far more cost.

I don't know what the shop was quoting so I have no idea if it was cheap or expensive. I am hoping they were planning on more than the two items you listed, but then I don't know what might have already been done.

Some maintenance can be done by the owner without much trouble.  However other items can vary from difficult for the owner to do to almost impossible for the owner to do.  For example, I don't know if you have a interference engine, but if you do and the timing belt breaks it can destroy the engine.  If you have the original timing belt, you are already in the seriously dangerous zone for that belt and it likely will be fore than that $500.

Thanks for the replies.

I bought the car used with around 45,000 miles and did not get a maintenance history with the car. I had the transmission fluid and filter changed at around 65,000 miles. So that needs to be done, thanks for that recommendation. When the transmission fluid and filter were changed I also had them replace the spark plugs/wires and fuel filter, so that was the last time any of that was completed.

Other than regular oil changes, the only other major maintenance that has been done was the timing belt just before it went over 100,000.

Sounds like you’re trying to do the right thing. Good for you.

Again, the owner’s manual and the maintenance schedule that came with it offer the BEST advice on vehicle maintenance. If you have these documents I recommend you read them (periodically) and follow them.

If you don’t have them I suggest you find them on eBay or at You need these documents. Owning a car without them is like walking thought the woods at night without a flashlight.