Is fortuner 2.5liter is timing belt? - 2006 Toyota Fortuner 3,0

100,000

nowhere. it has a timing chain that should last forever as long as you keep your oil in good shape. doesn't matter if you have a 4 cylinder or a v6, they both use chains.

Dan h described what would happen if your timing belt/chain broke.. fortunately the consiquences aren't as dire if your SERPENTINE belt snaps. Most vehicles have the following systems or devices powered by the front engine accessory drive belt (FEAD belt)
AC compressor
Power steering pump
Alternator
Fan (some vehicles do and some don't)
Water pump

All but one of these things can be lived without, at least for a short time. If your belt snaps and your water pump stops your engine will overheat in no time flat., say you're cruising through a rural area and your belt snaps a mile and a half away from the next town, your car will get you there, but you had better turn it off once you get into town. After a belt snaps you've got 2 miles before you absolutely need to shut your car down to avoid damage.

change fan belt and check tensioner are ok too

If the timing belt broke, your car won't run. Fortunately, it's not too expensive to replace, and as long as you are at it, may as well replace the water pump. Usually they have to dismount that in order to get at the timing belt. Generally that is that case, but it all depends on how each car is set up.

it means it is time to have your timing belt replaced.

standard is 100,000 km.

check thermostat

Yes you must remove the timing belt and gear to remove the water pump. I always recommend a new timing belt as part of the repair. Regards, Joe
PS kindly rate my answer. Thank you.

I just did the timing belts on mine; there is one main timing belt that connects to the crank, water pump, tentioner, idler, and to the intake cams on each head. The small timing belts are at each head at the rear of the head where the intake cam belts to the exhaust cams. If you pay like $30 on ALLDATAdiy.com website you can subscribe for an online repair manual for the vehicle; where they have instructions and diagrams. If you look on YOUTUBE under the search for "rover kv6 timing belt replacement" there is films on this engine.