Tensioners for 911 SC. When to replace?

Denis54 · 06-20-2002, 11:29 AM

I have a 911 SC with only 15,000 miles on it. I am the original owner and needless to say I have never used it much. I am just retiring and plan on using my SC a little more. Of course, I want to make sure my car is in perfect condition.

I have asked my mechanic a few rimes in the past about installing the new improved chain tensioners. He always said that it should be done but that there was no rush to install them as my car is still brand new.

What is the general consensus about tensioners? When is the right time to replace them?

island911 · 06-20-2002, 12:18 PM

Wow, a 911 SC with only 15,000 miles on it. wow.
. . and welcome.

To your question, click the link below. (some good stuff)
Chain Tensioners, when do you worry??

Vipergrün · 06-20-2002, 12:37 PM

Denis54,

the car sounds terrific! Welcome! Do you have any pics you can post? We'd love to see it.

As far as the tensioners, you'll probably get a lot of varying answers, but it's a pretty easy job and good insurance.

cheers
-Brad
80SC

chuckr · 06-20-2002, 12:56 PM

I had 160,000 on my 83SC before I put the tensioner upgrade on,
as long as you have the hydra stops on you really do not have to worry ! Good luck with your SC and enjoy it !

Swank911 · Swank911's Garage

I would agree with all those who recommend chaging as soon as possible.

I broke a chain guide and had a tensioner w/ high mileage, so we had them replaced.

In my frugality, had them replaced with stock tensioners. Ff course the F* er of a mechanic I was using at that time, did not explain the difference between the two clearly or fully.

In less than 5K miles, one had failed. Luckily no major damage was done.

I had my new engine put in with less than 8k on a the rebuild and had the carrera tensioners pulled from my 2.4 and placed on the new motor.

speeder · speeder's Garage

It's impossible for anyone to tell you if and when your tensioners might fail, most never do, but they certainly don't wear in a car parked in a garage, which yours has obviously been doing.

There are thousands of SC's with 6-digit miles that have original tensioners, once again total failure of these(930 part#) is very rare, usually IF they do fail the engine just gets REALLY noisy, but total failure is a serious enough thing that most of us have switched to later style(carerra) tensioners. I am going to install them in my SC as part of a partial overhaul this year, approx. 120k miles.

Hope that helped, have fun with it!

Zendalar · 06-20-2002, 01:33 PM

Springs do age if they are compressed, even though the car has not been run a lot.

But on the other hand, thats just my opinion. What would I know

Can't even get my car running well, heh.

rstoll · 06-20-2002, 01:46 PM

I did the upgrade at 130,000 miles. The trick is to change them just before they collapse.

Early_S_Man · 06-20-2002, 01:51 PM

Denis,

You didn't say what year your SC is? The upgraded double-bushing chain-wheel carriers that were fitted to mid-year 1980 models are even more important that the tensioner design itself!

Denis54 · 06-20-2002, 03:14 PM

My car is a 79 SC Coupe. I never heard of upgraded double-bushing chain-wheel carriers. Can you elaborate a bit about them?

I notice that Early_S_Man has a 340S Barracuda. My first car was a brand new 4 speed 340 Dodge Dart GTS. These had a special hi-performance camshaft that was only used in 1968. The idle was pretty rough but the engine produced a lot of power. This was a sister car to the Barracuda. Hope you enjoy yours as much as I enjoyed mine. One of the most fun car I ever had (of course I was 20 back then. That might have helped the fun factor).

Doug E · 06-20-2002, 06:47 PM

Holy cow, only 15k miles? How have you been storing it for all these years?

Replacing the tensioners is kinda like insurance ... you don't know for sure that you needed it until it is too late!

Welcome to the board and have fun on the road.

glenndeweirdt · glenndeweirdt's Garage

Wow, I thought I had a low mileage Sc with 25K on the ODO.
I have yet to replace the tensioners, but I know it needs to be done. Don't forget the popoff valve as well!

hermzz911 · hermzz911's Garage

I replaced mine when my worrying about them failing started to take priority over enjoying a 'spirited' drive.

Peace of mind is a beautiful thing (especially when you're behind the wheel of a 911sc with the tensioner upgrade and popoff valve!).

Just my $.02.

Denis54 · 06-20-2002, 09:00 PM

I have garaged it all the time. Typically over the last 10+ years I have driven 5-6 times a year for a total of 300-500 miles per year. Not a lot but enough to put a smile on my face everyone of those times.

My every day car is a 97 M3. It does everything better than the 911. Nevertheless every time I use the 911 I come back home smiling. I have owned the M3 for 5 1/2 years and will probably replace with something that rides softer. I really need a car with an auto trans. My wife will not even try to learn to drive a manual. When I use her car she is stuck home with an M3 and a 911 in the garage that she cannot use. She has been patient enough.

All this to say that I will now use my 911 probably 2-3000 miles a year. I will put the tensioners on. I do not want to risk anything. I have the chance to own a fantastic car, I will take care of it.

By the way how many hours would a good mechanic need to install the tensioners?

hermzz911 · hermzz911's Garage

You're looking at 4-6 hours of mechanic's time. Kit is about $400- $500, depending on where they get it. There was a previous post here by John Walker regarding what he charges -- I just wished I lived closer to him.

By the way, I have a 528i which my wife loves -- a quiet, yet sporty ride.

911pcars · 06-22-2002, 12:24 PM

Double bushed idler arms first appeared in '81. B. Anderson says tensioner failures were due in part to the early arms binding on the pivot. The wider bearing area on the later arms reduce binding and thus increase tensioner life. Carrera hydraulic tensioners are the latest but the Turbo tensioners seem to hold up fine. Save your money until it starts rattling (which may be a long time from now). The mechanical stops provide cheap insurance.

Regards,
Sherwood Lee
http://members.rennlist.org/911pcars

Wayne 962 · Wayne 962's Garage

I agree (somewhat) with Warren - the newer style, wider idler arms are as important as the chain tensioner upgrade. Porsche early on identified this as one of the causes of tensioner failure. Do not perform the upgrade without these idler arms...

-Wayne

Denis54 · 06-22-2002, 02:00 PM

Are newer style, wider idler arms included in the tensioners upgrade kit? If not, which part number should I be looking at? How much do they cost?

scedmonds · scedmonds's Garage

I had my wrench do this upgrade in March '01, when my '83 SC had 147K on the original engine.

The tensioner upgrade kit was $495 -- labor for this install and the "30K service" was $435 (my invoice doesn't separate labor for the two).

I'd figure $800, though you might end up with some change, there.

As mentioned before in this thread, it's cheap insurance compared to the damage that can happen when the old tensioners go.

Welcome to the board and keep us informed about your renewed love affair with your SC.

Cheers!

C.

island911 · 06-22-2002, 04:35 PM

$800 .. .I don't know I would call that "cheap insurance"
That's about 20% the cost of an SC motor. . .and Roland says he has seen more failures in the updated type (due to oil pressure surges blowing the seals)
I was once convinced these were the way to go. I can't say that after reading Rolands comments. Although, I would update to the wider idler arms.

I'm guessing the wider idler arms are included in the tensioners upgrade kit. .. in which case I'm sure you can find them cheap as take offs from people doing the "upgrade" to 81-83 SC's.