Skyactiv Hydraulic Belt Tensioner Oil Leak - Pics

[The Critic]

I had a 2013 Mazda 3 skyactiv in the shop for some maintenance work and during my usual inspection, I found an oil leak from the hydraulic belt tensioner. Since the vehicle did not have prior dealer service history and was just outside of the 3/36 warranty period (49k), I received approval to do the repair.

Untitled by The Critic, on Flickr

Lots of oil covering the tensioner assembly.

Untitled by The Critic, on Flickr

Here is a better view of the tensioner after it was removed from the vehicle.

Untitled by The Critic, on Flickr

Comparison of the old tensioner with the new one. Both were made by INA, but it looks like the new one is slightly revised.

Untitled by The Critic, on Flickr

Made in Slovakia - that's a new one.

Kudos to Mazda for making the replacement process a breeze. The tensioner is held in place by one nut and one bolt, both being 12mm. The bolt stays in the tensioner after loosening it - it may not come out while the tensioner is still in the car. It is not necessary to remove the side engine mount for this job. MSRP on the tensioner is $134 and the whole job takes about 1 hr including the clean-up of the grease that slung everywhere (but the belt).

If you own a 2.0L skyactiv, I would keep an eye on this part and get it taken care of before it fails completely.

 

[Trav]

INA is F.A.G. and are good quality, lots of engines using this type inc Honda. If they leak they are finished, apply very slow and steady pressure when compressing these to get the belt on.

 

[SwampSurvivor]

Call me regressive, reactionary ... but I like a good MANUAL tension setup.

 

[440Magnum]

Originally Posted By: Miller88
Call me regressive, reactionary ... but I like a good MANUAL tension setup.


The only downside is that a manual (only) tensioner setup doesn't absorb any of the load reversals and shocks on the belt. So you trade shorter belt life (and higher risk of unexpected belt failure) for more complexity in the tensioning system. Alternator overrunning clutches exist for the same reason, and are why belts can now last well over 100,000 miles. But then when you do replace the belt, you're also supposed to replace the tensioner and O/R clutch at the same time. Great for first-owners that trade the car off before the maintenance is due. A headache for people who keep their cars longer and do the maintenance.

 

[DBMaster]

This made me have a look at mine. It's not slinging any oil, but there does seem to be a slight amount of seepage. At least, there is a bit of dirt stuck to the area around the rubber boot. Looks like the online OEM parts price is between $90 and $100. I'll be keeping an eye on it. Thanks, Critic!

 

[SwampSurvivor]

Originally Posted By: 440Magnum
Originally Posted By: Miller88
Call me regressive, reactionary ... but I like a good MANUAL tension setup.


The only downside is that a manual (only) tensioner setup doesn't absorb any of the load reversals and shocks on the belt. So you trade shorter belt life (and higher risk of unexpected belt failure) for more complexity in the tensioning system. Alternator overrunning clutches exist for the same reason, and are why belts can now last well over 100,000 miles. But then when you do replace the belt, you're also supposed to replace the tensioner and O/R clutch at the same time. Great for first-owners that trade the car off before the maintenance is due. A headache for people who keep their cars longer and do the maintenance.



The belt on the Focus is now squeaking. I'm afraid to touch it because I know that, for the rest of it's life, I'm going to be replacing the tensioner and belt in the spring and fall every year. That was the case with the Taurus ... once I touched the OE belt and tensioner that was it.

 

[artificialist]

The Toyota 2AZ-FE uses a similar tensioner and I have replaced many of them.

 

[DBMaster]

Originally Posted By: artificialist
The Toyota 2AZ-FE uses a similar tensioner and I have replaced many of them.


THAT'S why the thing looked so familiar. I changed the serpentine belt on my GF's Highlander quite a few years ago. I have to say that this type of tensioner makes the belt super easy to change. Hers never leaked in over 150,000 miles.

 

[artificialist]

Originally Posted By: DBMaster
Originally Posted By: artificialist
The Toyota 2AZ-FE uses a similar tensioner and I have replaced many of them.


THAT'S why the thing looked so familiar. I changed the serpentine belt on my GF's Highlander quite a few years ago. I have to say that this type of tensioner makes the belt super easy to change. Hers never leaked in over 150,000 miles.


I think Toyota eventually redesigned those belt tensioners because failures were so common.

 

[Igork]

Hi, any adjustments needed after tensioner replacement ? I don't see any tension adjustment mechanism on it .

 

[Mr Nice]

2.5L might also have this problem ?

 

[nobb]

Are there any major issues from running a leaky tensioner? I would imagine the spring tension to still be good, just that the loss of oil reduces dampening. But how much does that dampening matter since the range of movement on the tensioner is so small?

 

[MarkM66]

Originally Posted by artificialist
Originally Posted by DBMaster
Originally Posted by artificialist
The Toyota 2AZ-FE uses a similar tensioner and I have replaced many of them.


THAT'S why the thing looked so familiar. I changed the serpentine belt on my GF's Highlander quite a few years ago. I have to say that this type of tensioner makes the belt super easy to change. Hers never leaked in over 150,000 miles.


I think Toyota eventually redesigned those belt tensioners because failures were so common.


Also looks very similar to the one on my 2004 1ZZ-FE . 273k miles on the original unit, and still going.

 

[DBMaster]

The Critic (I believe it was him) showed some photos of one of these a couple years ago. I've been watching mine ever since. Mine's not leaking yet. Rock Auto sells Dayco and Gates brands of this item. I don't know how they compare to the OEM part, though, as far as quality.

 

[BMWTurboDzl]

Tensionser failure seems common across all makes. I keep an eye on mine, looking/listening for the typical "wobble" which indicates failing bearings on the pulley.

 

[nthach]

Originally Posted by DBMaster
The Critic (I believe it was him) showed some photos of one of these a couple years ago. I've been watching mine ever since. Mine's not leaking yet. Rock Auto sells Dayco and Gates brands of this item. I don't know how they compare to the OEM part, though, as far as quality.

FWIW, when I used an aftermarket tensioner, I bought a Goodyear one that happened to have a Litens part in the box. Gates and Dayco don't make tensioners, I think they'll get them from China or if the COO on the box is Canada or Europe, more than likely Litens or INA/F.A.G/Schaeffler.

 

[WyrTwister]

To me , this is a problem in search of a solution . I fail to see what is wrong with the spring loaded tensioner used on many cars ?

 

[DBMaster]

Since I change my belts today (2012 Mazda3 w/Skyactiv) I wanted to share what I learned about the tensioner. It is NOT hydraulic. The rubber grommet pulls off easily and there is a coil spring inside the cylinder. I thought I might have to replace mine because there had been a little seepage over the 100,000 miles I've had the car. There is just a bit of oil sitting in the compartment to keep the spring lubricated. I poured that tiny bit out (a couple of teaspoons at most) and put in a bit of hydraulic jack oil I had around. The spring, structure, and pulley bearing were in perfect condition. I just cleaned up the part and the grommet and put it back together. I could find no evidence of any sort of dampener assembly inside the tensioner.

So, short story is that a little oil seepage is normal and unavoidable due to vibration. The grommet is not super tight fitting. So, unless your pulley bearing is worn there is no need to replace the thing.

 

[ctechbob]

Originally Posted by WyrTwister
To me , this is a problem in search of a solution . I fail to see what is wrong with the spring loaded tensioner used on many cars ?


I was kind of wondering the same thing. I easily get 100k out of belts and the 2003 J Series in my Accord has the original tensioner at over 200k. I'm sure the bearing won't last forever, but when it comes time to take the 2 bolts out to replace it, I won't be crying about short life.

I'm a big Mazda fan, but this seems like a German Mercedes or BMW engineer got hold of designing parts of that motor and decided in usual fashion to over-complicate things.

 

[The Critic]

Originally Posted by DBMaster
Since I change my belts today (2012 Mazda3 w/Skyactiv) I wanted to share what I learned about the tensioner. It is NOT hydraulic. The rubber grommet pulls off easily and there is a coil spring inside the cylinder. I thought I might have to replace mine because there had been a little seepage over the 100,000 miles I've had the car. There is just a bit of oil sitting in the compartment to keep the spring lubricated. I poured that tiny bit out (a couple of teaspoons at most) and put in a bit of hydraulic jack oil I had around. The spring, structure, and pulley bearing were in perfect condition. I just cleaned up the part and the grommet and put it back together. I could find no evidence of any sort of dampener assembly inside the tensioner.

So, short story is that a little oil seepage is normal and unavoidable due to vibration. The grommet is not super tight fitting. So, unless your pulley bearing is worn there is no need to replace the thing.

Interesting, thank you.

The replacement tensioner has remained dry for over 60k, fyi.