Pressure fed tensioner failed

[timc]

No response on the turbo side, so I thought I'd try here. Drove my 86 930 down to Orlando this weekend for my daughters swim meet, and as I pull into the hotel I hear the classic rattling just off of idle. (Had several fail in early cars) So this morning I go out to the car, crank it up, no noise. After the swim meet I begin the 7hr drive back home, stopped after 2hrs, (no noise), 3.5 hrs (no noise) then after approx 5 hrs heard the rattling just off of idle. Funny thing is it takes a while for it to start making noise. I stopped on the way home at a friends house just to confirm. So I then shut the car down after we both agreed it was the dr side tensioner, and we talked for about an hour, then started it back up for the 30min drive home and no noise the entire way home.

This is my first experience with a pressure fed tensioner failure. Any way to rebuild/ clean? or do i just replace.

Friend was also telling me that Porsche updated the orifice on each of the two oil lines that supply oil to the tensioner to a smaller diameter for better pressure, so I'm wondering if that could help????

[theiceman]

Wow you got balls I gotta give you that . driving a car on a failed tensioner. For the damage that can do don't mess around , just change it along with the ramps.

[theiceman]

Wow you got balls I gotta give you that . driving a car on a failed tensioner. For the damage that can do don't mess around , just change it along with the ramps.

[N11Porsche]

I would not risk, what could be catastrophic engine damage, by driving the car any more. When the tensioner fails the pistons hit the valves $$$$.

The fact that you've driven the car all these hours, with the noise, could mean there is something else wrong?? Until you've taken the cover off and confirmed what it is, I would not drive (or even start) your P-Car.

[Zeke]

Wait, are 930 tensioners and 3.2 pressure fed the same?

[equality72521]

Originally Posted by milt

Wait, are 930 tensioners and 3.2 pressure fed the same?

Yes. I asked the same question and it turns out that the 1984 and up pressure fed (Carrera) tensioners were put on the 930 after a certain date (maybe 1984?). Before that the 930 had the mechanical ones.

[Rot 911]

This is more of a failing tensioner then a failed one as we know what happens when the tensioner completely fails. 4-5 years ago there were a batch of bad carrera tensioners being sold that were prone to failure so it is not unheard of. Just buy a new one and put it in.

[timc]

Originally Posted by Kurt V

This is more of a failing tensioner then a failed one as we know what happens when the tensioner completely fails. 4-5 years ago there were a batch of bad carrera tensioners being sold that were prone to failure so it is not unheard of. Just buy a new one and put it in.

Thanks Kurt.

Yes, I should of stated "failing" as opposed to failed. Over the last 25yrs I've driven many miles with a failing hydraulic tensioner to get back home, not a big deal if you are careful. At this point mine is very intermittent, only showing up after driving the car for long distances, then even at that time it is only a slight rattle just off of idle, then at above 1.5k the engine is just as smooth and quiet as ever. I guess I was just "shocked" at the pressure fed signs of failures, and did not know if these could be cleaned in some manner. I thought tensioner issues were behind me with the pressure feds on my 930.

I was also curious of the orifice "update" that Porsche came out with in the very late 80's to decrease oil flow thru the spray bar, thus increasing pressure to the tensioners. Was not sure if this would have an affect on tensioner performance.

[Tim Polzin]

I had somewhat the same experience. Not really loud, but definately noticable at idle and low RPM and also intermitant. The noise was also on the driver's side. Removing the chain cover, the tensioner was soft for the first couple of mm, then was hard. I replaced it and everything was back to normal.

Tim

[PCA7GGR]

Tim,

I had a similar failure on the driver's side tensioner of my '84. I was advised that the oil-fed tensioners did not collapse completely but that they should be replaced as soon as the partial failure occurs.

[snbush67]

So they do not collapse all the way? Like a built in safety collar? I guess then a partial failure would mean completely failed?

[timc]

Originally Posted by PCA7GGR

Tim,

I had a similar failure on the driver's side tensioner of my '84. I was advised that the oil-fed tensioners did not collapse completely but that they should be replaced as soon as the partial failure occurs.

Yeah, That's what I kind of thought. Some just freak out when you mention tensioner. I was not really concerned about driving the car home, just more shocked at the signs of a pressure fed failure. Put it this way, I was not going to rev the car then all of a sudden close the throttle!!!!

[Porsche-O-Phile]

I wouldn't even start that engine. Replace immediately.

[WERK I]

Take your tensioner covers off and make sure the tensioner(s) are not fully extended. As the chains stretch over time, the useful travel of the tensioner gets used up and the tensioner arm can actually hit the chain case. That may be the noise you are hearing. This will only occur on the driver's side tensioner, I believe.

[911 tweaks]

QUESTION: can the bolt on collars go on the pressure fed tensioners to prevent any collapse of the piston into the tensioner? Basically the best of both worlds... a pressure fed tensioner and WHEN, not IF, the tensioner fails, the collar prevents the piston from going down into the tensioner and all of those lovely issues that jump out then???
Thanks,
Bob

[timc]

So, any advice on updating to the smaller orifice?

[911pcars]

Tim,
Not sure if the smaller orifices in that fitting make that much difference in this area. The oil flow is obviously low (re: small oil supply line), and the designed oil bleed doesn't require a lot of oil volume to maintain the proper slack in the chain system.

Don't thing there's enough piston shaft exposure to clamp on those collars. However, there's a way to prevent total piston collapse on the pressure-fed tensioners by inserting a metal dowel under the piston to restrict the collapse height.

Somewhere in the archives.

Sherwood

[ChrisBennet]

Originally Posted by 911 tweaks

QUESTION: can the bolt on collars go on the pressure fed tensioners to prevent any collapse of the piston into the tensioner? Basically the best of both worlds... a pressure fed tensioner and WHEN, not IF, the tensioner fails, the collar prevents the piston from going down into the tensioner and all of those lovely issues that jump out then???
Thanks,
Bob

You can't use the collars on the pressure fed tensioners but their is a mod you can do to the internals of the tensioner.
-Chris

[cgarr]

Here is the mod, I have done it, very simple:

http://66.236.61.177/showthread.php?t=199819&highlight=tensioner+mod&page=2