I was tearing in to my motor today to find out where this coolant leak was coming from. Well its the water neck/ upper timing belt idler pulley.

Im having one of my friends help me out because him and i were just working on his 3vz (95). He was looking at my tensioner and mine is hydraulic and his was spring.

Which is better?
Can you swap a hydro for a spring set up?

The reason i ask is because when i took off the front plastic cover, the belt was lose around the top idler. If i went to a spring set up would the belt be tight all the time?

 

bump. lol

 

The spring in the early type tensioner is not actually responsible for belt tension, it's used primarily to help set tension before the tensioner bolt is snugged.
The later hydraulic style tensioner is better at maintaining consistent tension as the belt swells and contracts due to temp change and wear which is generally preferable to the solid "spring" type.

To swap to the hydraulic tensioner you'd have to swap the fan bearing plate, the new tensioner and the tensioner idler pulley/pivot arm. I don't know if there are provisions in the older style block for the newer style idler arm.

Here is the newer style. You'd need the hole located below the passenger bank timing gear to be able to use the hydraulic tensioner's pulley arm.



Here is the older style that pivots off of the water pump.



Based on these two pictures it looks like the there is the same tapped hole in both heads which could make the swap possible.

 

My friend has all the parts for the spring set up but im going to stick with my current set up.

When i pulled the front cover, the belt was lose. just at the upper idler, everwhere else was tight. This is why i bring this up. Does the hyrdo tensioner take all the slack out when the engine is on?

 

Once the engine rotates the tensioner will extend and tighten the belt.

 

yo the holes are the same for the hyrdo and the spring. no difference at all!!!!!!!!