Just wondering

rstoll · 07-17-2002, 03:18 PM

Now that most all of us have upgraded to the pressure fed tensioners. Has anyone out there ever had a first hand experience with whacked valves due to a collapsed tensioner?? I say this because no one has ever said, "I upgraded to the pressure fed tensioners after a failure. Mine were 16 yrs old when I changed them.

Wayne 962 · Wayne 962's Garage

From our experience here at Pelican, customers either have them work properly when starting the car, or not. The ones who did not, did not follow our instructions for priming them, however.

I have not heard first-hand of anyone who has had bent valves from a pressure-fed tensioner. Still, there are many posts on this topic debating this issue. I still recommend them (in the new book too) for all Porsche engines that can accept the upgrade kit (1968 or so, I can't remember from the Mediteranean...)

-Wayne

rstoll · 07-17-2002, 04:10 PM

No, I am asking about the original tensioners failing before the upgrade.

cegerer · cegerer's Garage

One of my original tensioners failed on my old 73T (car was 9 years old with 90k miles at the time). What a racket that made! At the time, I didn't know what it was and drove slowly back home and then 10-15 miles to my mechanic the next day!!!! Didn't damage a thing, somehow.

-- Curt

pwd72s · 07-17-2002, 04:45 PM

I switched to the pressure fed ones some years ago, after years of chain tensioner paranoia...and the mechanic who did the change for me at that time, late 80's, did NOT do the priming in a bucket of oil thing. (This is not the mechanic I trust most today, guys.) But, guess I was among the lucky. No problems so far. I'd think problems would have shown up by now?

Early_S_Man · 07-17-2002, 04:47 PM

Robert,

I think most of the tales about engine damage are myths! It seems that most failures make enough racket that the owner notices and curtails driving until he/she finds out what might be making the noise ... and gets them replaced! End of story ... nothing dramatic, except for that chill up the spine that the 'chain dragging out of a trashcan' noise causes!

One of mine failed at 48K miles, but it only took about five seconds of that racket for me to kill the engine ... and it was never run again until the 'turbo' tensioners and new ramps were installed! No damage!

turbo dave · turbo dave's Garage

Here's a question for you all: if I remember right, Roland Kunz was recommending the 930 tensionners for early cars, rather than the oil-fed. Any opinions on this?

Thanks

pwd72s · 07-17-2002, 05:08 PM

Damned good question Dave. But since I already committed to the oil pumpers, I don't have an answer.

rstoll · 07-17-2002, 05:21 PM

Yeah Warren, that's about what I am reading lately. When mine made the death rattle it was actually due to a broken (missing) chain ramp. I also installed my pressure fed tensioners without any priming. They pumped up immediately on startup. Been running them for over a year now with no problems.
I read a piece recently, I think in Pano, about early 911 owners carrying an extra set of tensioners on long trips, knowing they may have to make a roadside change. Didn't sound like the instant catastrophe that we have been imagining. You hear the tensioner fail, you pull over and change it. I was under the impression when the tensioner failed, the valves were bent.
Glad to have the pressure feds anyway.

nostatic · nostatic's Garage

It's funny how things become lore. It would be interesting to know the real data involved in this one. For instance, how many actual tensioner failures were there, and of those, how many people just kept driving along until the valves bent. My guess is it didn't take too many failures to become the stuff of legend..."change to oil-fed or surely perish!"

Maybe it's time for a poll

pwd72s · 07-17-2002, 05:47 PM

Nostatic? You could be right..only once in my "old fart" history did I actually witness a failure of an early tensioner. But believe me, it made enough of an impression that the paranoia remanis...the poor victim was barely past warranty.

Early_S_Man · 07-17-2002, 06:34 PM

Robert,

Well, that sounds like a worthwhile addition to my 'spares' inventory for vacation trips, what you might call a 'retrograde' tensioner kit ... the 'turbo' tensioners with collars had only 12K on them, and can be milled down to fit the double-bushing carriers, old covers, gaskets, new 'old' oil lines & hardware, pluis muffler gaskets ... ought to fit in a medium pizza box!

rstoll · 07-17-2002, 06:47 PM

Yeah, those Porsche tensioners might be hard to find on a road trip, not to mention costly. I remember a few years back while camping in the Ozarks. We were packing up to come home and the alternator wiring on the Volvo fryed on startup. We were the last people leaving the campsite. I had my GE toolbox in the trunk with spade terminals and wire. Rebuilt the harness on the mountainside. Park ranger gave me a jump start. I told him I hoped the alternator was ok. He said I hope so, they can't even "spell" Volvo up in these parts. My patchwork held up for another 2 years.