j.kenzie@sbcglobal.net

OK. Don't get me wrong. I ordered Porken's tensioner. But I'm pretty sure my tensioner is at best oil coated on the inside. I re-filled it and it promptly leaked all over my floor. My car still runs great, winter or summer. Hot or cold is all the same. Do we really need the function delivered by our tensioners or would one simple screw adjustment do the job?

StratfordShark

I also got annoyed re-filling the tensioner - despite loosening bleeders I'm sure most of oil came back out and dripped over me/garage floor! I think I should have removed bleeders entirely...

From what I understand from threads here though the oil-filled tensioner allows the tension to accommodate and compensate for changes in engine temperature, which would not be the case for simple screw arrangement.

Now I'll hand over to the real expert mechanics and engineers here!

SeanR

There's more than just refilling them when you have them out. Replacing the rubber and cleaning it totally is required. That means cleaning out the bleed holes, blowing them out with compressed air works well.

No expert here, just done a few at rogers.

a4sfed928

I think the oil is in there to transferr heat to the temperature compensating washers.

toofast928

Has anyone ever had a T Belt failure in 928? Belt snap, teeth shread off, jump time?

the flyin' scotsman

The theory as I understand it. The engine is aluminium and expands with heat. As it expands the tbelt is tighter that when cold. The OEM tensioner dished washers 'flatten' with the heat which reduces their collective length which loosens the tbelt. The oil in the tensioner is to assist heat transfer to the aforementioned washers.

How much the engine expands compared to the washers flattening I don't know.

Just install the Porken tensioner and forget about it.

JP Rodkey

It isn't just for temperature compensation. It's also proper mechanical design. That belt is critical to operation of the engine. Imagine what could happen if a rock got past the cover and between a gear and the belt, or some other chunk of debris fell down through the ventilation hole at the top of a cam gear cover? The tensioner greatly reduces the risk of engine damage (and operation) by allowing the timing belt to "ride through" events that could otherwise damage or disable the engine.

mark kibort

my tensioner doesnt have oil in it. i figure its good to have the tension be a little tighter when the engine is hot and when im spinning the engine to 6000rpm for a few hours.

Brett Jenkins

I had a tensioner failure, resulting in a slack t-belt and bent valves on the driver's side. The tensioner came loose somehow. I never had it off and there were about 10k miles on it since the previous owner had the t-belt done. I believe that included a tensioner rebuild. This was in the 90 s4 with 190k miles, which is now in someone else's hands getting a rebuild (parital, I think) and boost last time I heard.

Bill Ball

My experience with no oil in the tensioner is that the belt life is reduced and there is extra wear on the cam gears and other components due to over-tensioning of the belt when the block is warm and expands, as explained. The oil also exerts some dampening effect on belt vibration in 83 and newer tensioner designs.

You could do away with it by replacing the stock tensioner with a Porkensioner. Do a search for more info.

JEC_31

Many people have.

In the 32-valve "interference" motors, the mis-timing can and usually does result in bent valves from the pistons coming up when the valves are left hanging down.

Hot topic, indeed.

bernard farquart

I had a tensioner fail in my 1984 16v. this allowed the passenger side cam to get about 30 degrees out. I had no valves bent, and replaced the belt and tensioner.

brutus

There is really nothing in the tensioner to fail. It can not collapse because it is a solid bolt. The only thing it can do is when the washers change shape it lowers the tension slightly. Mechanics sometimes may tell you it failed but that is BS. The very early tensioners did not have the bleed holes to let the 90 wt touch the engine block but heat transfer still was used ,no paper gasket, to allow the washers to flatten out. It is a very simple system.

V-Fib

My tensioner shoulder bolt failed last week. On start up. The belt slipped and shredded some of the belt. Ordered another belt, replaced the tensioner shoulder bolt. No problems since. Glad it was a non-interference engine. After 28 years I guess the bolt got a little weak. I am **** about keeping the proper tension on the belt and check it religiously.

mark kibort

That is not really the tensioner, but an integral part of the system. i had one snap on tightening, so being that it is so critical, i change it on every belt change, or water pump change. another pretty scary weak link!

mk