355 Advice about HYDRAULIC TIGHTENER MAJOR SERVICE

I would inspect them and see how they hold tension once engine is out. I personally would probably change them every second engine out so once every 6-10 years depending on your risk appetite and engine out schedule. They can go off just sitting still so mileage won’t really affect it much I think. I’d do it based on time.

 

Another factor to consider is the storage conditions. If the car is subject to heat and humidity as well as cold and damp conditions then I would definitely consider putting new tensioners in. My .02

 

I would leave them alone.

 

I think component failures are related to use-case and factors such as environment conditions (extreme heat/cold, humidity etc), but I can share my own experience:

I had one hydraulic tensioner fail on my car when it was around 13 years old and around 50,000km (30k miles). I changed them both and since then they have been fine, 10 years, 15,000km and 3 majors later I’m doing the engine-out again this winter and will take another long hard look at the tensioners as I do every major. I might even change them as a preventive measure, but I think with my use case they are probably still fine for another 5+ years at least.

In my case the failure was not a big deal, it was very rattly when cold, but went away when hot. Basically the plunger had corroded. In my particular case there was no real chance of the belts skipping a tooth. If I change them it will only be to avoid the hassle of needing to pull the engine early. The thought of a tensioner failing doesn’t scare me unduly. A tensioner bearing seizing on the other hand would be different story...

 

I did not replace them on my third engine out and 1 possibly failed causing bad problems so I will start replacing every major.

I tested them , they looked good, operated good, so not positive what happened only know cam belt jumped two teeth on bank one so all I can tell you is what happed for sure.

having said that I know most leave for at least 2 majors and most have never had the problem I did

 

One of my tensioners failed before my last engine out, it just rattled when cold. Went away once warm. Was unnerving but I still drove it a few months before pulling the engine.

 

Both were replaced on our car in March of 2018 during our major. Had a solid rattle which we deduced was actually the tensioner wheel arm (that the tensioner assembly, well, tensions) was starting to seize up on it's bushing. We refurbished that bushing (checked other one, it was fine) and installed new tensioners to be safe.