Hey I've got a 2003 Montero Limited and the hydraulic tensioner that keeps the timing belt from making a flapping noise has failed. Replaced it 19,000 miles ago when I did timing kit. Stupid gadget. Why do they use such ridiculous contraptions? It fails and causes the belt to flap when under 2,500 rpm, potentially damaging the belt or even skipping a gear(s) damaging the motor.

I don't recall if I have to remove the timing belt to replace the tensioner. I have to do this under an open carport in the Colorado winter so I want to do it fast as possible, removing as little as necessary.

I know I have to remove the cooling fan/shroud, serpentine belt, plastic timing belt covers, the accessory plate in front of the timing belt area.

After those, can I simply unbolt the hydraulic tensioner and replace it, doing the adjustment procedure with a torque wrench and the special tool? Tell me I do NOT have to remove the timing belt and all that extra pain, please. I don't remember.

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No need to remove the timing belt. You can replace just the tensioner. It is just two bolts holding it.

The reason they use hydraulic tensioner is because any rubber belt stretches and shrinks with different temperatures. The tensioner, keeps the belt at the same tension regardless of the temperature. A spring loaded tensioner (like the one on the serpentine belt) has lower tolerance for belt tension uniformity. It is not an issue on the serpentine belt, but you want tighter tolerance on the timing belt. Unfortunately, like any tensioner, they do occasionally fail. I too had one fail on me once. It is truly a scary sound at idle.
You should be able to do the job in the middle of Colorado Winter. Just give yourself enough daylight and don't touch any tools with your tongue

 

Lol, cool. I was hoping so. The timing belt and all that double checking adds another hour of fooling with stuff.

I think I have to open or remove the thermostat housing also, better have some antifreeze...

The tensioner i put in has got a lifetime warranty so I hope to get the part free anyways. It was about $50 in parts stores. First timing kit I did I didn't know to replace the hydraulic tensioner also and 2 weeks after putting belt on it started to flap. I was so po'd I had to tear all that apart again. Took me 3 months to figure out it was that. I replaced the hydraulic valve adjusters in error thinking one or more of them was problem, but no, it was stupid hydraulic timing tensioner the whole time! Maybe I put it in wrong...and failed prematurely due to my slackery. Lol

 

There is no need to open up the cooling system in order to replace the tensioner.

The most important thing during this job is to set proper initial tension on the belt. If you do not have a little specialty wrench for torque setting the tensioner pulley, you can use the tensioner pin as a guide. When you start you work (tensioner not installed), the pin is nearly impossible to pull out. Once you install it on the engine, tension the pulley so that you can spin the tensioner holding pin in its hole without any resistance. If you can do that - you set proper initial tension on the belt. Torque the pulley holding bolt and re-check the pin again.

 

I think you're also supposed to rotate the crank a couple of turns (720) in order for both sprockets to make a 360 and then recheck the pin removal tension.

 

This went well. Didn't even have to loosen and re-torque the tensioner pulley. I spun the crank 3-4 times and waited for the 5 minutes each time.

Do not buy the cheaper Chinese made hydraulic tensioners, they do not last more than 20,000 miles. Buy the Gates or other German or American made ones. They last the life of the belt and then some.

 

100% correct