HELP- 997.2 Belt Tensioner!

[flatsixing]

Guys,

 

Was waiting for my son this week in hot weather with the AC running.  As we left our destination and I began to drive away, I heard a loud pop, followed by grinding and squealing.  The battery generator warning light came on and being only 2 miles from home, I shut off the AC and made it to the garage.  Upon inspection, my serpentine belt is fine, but I have an obvious problem with the tensioner.  I have searched this site and the internet for a DIY.  Anyone have anything they can share?

 

I am thinking in need to replace the tensioner completely.  I also, reluctantly, noticed what looks like a sheered bolt.  (pictured)

 

Would appreciate any input!

 

[Loren]

Exact model and year of car please?

[flatsixing]

Loren, we can always count on you.

 

2009 (997.2) Carrera S

VIN WP0AB29979S720649

[Loren]

Let me do some research -- 997.2 had a new engine that has not really shown idler issues (at least not like the 996/997.1 series cars).

[slicky rick]

Yup pics look like the dfi engine. You've sheered the bolt. You need to remove the old bolt via drilling or "easy out" tool. Then replace with a new one. That's it you'll be back on the road in no time. I would think when the belt was replaced the guy who fixed it forced the tensioner idler too much and may have damaged the bolt. Your fortunate it happened that way and not on a long highway when your running at high speeds.

[flatsixing]

Thanks everyone for your reply's. I have been traveling and for whatever reason, have not been getting notifications on your postings. slicky rick, your assessment is correct. The tensioner is no longer in the right position and the tensioner pulley has dropped down to the lower right and wiggles excessively. The hydraulic pulley (red arrow) is the only thing in place right now. The bolt within the 24mm section is loose and can pull out. Something has caused this to suddenly occur. I was sitting stationary with the AC running in 105 temps for about 10 minutes. I wonder if my AC compressor seized? The AC pulley still turns, as do all of the other accessory pulley's. Surprised the belt did not break with this, but something of force caused the bolt holding the water pump housing to the engine block to shear the bolt to the left of the yellow arrow. Can it possibly be that all that needs to be replaced here is a new tensioner??? I see no DIYs on this either...

[RFM]

Check whether the alternator freewheel pulley is not jammed, this causes excessive vibration in the poly V belt which can break off mounting bolts.

 

[flatsixing]

RFM, pulley appears to turn freely.

[flatsixing]

All of my accessory and crankshaft pulley's seem to be in tact.  Wondering, if through some research, the loud pop I heard was the high pressure relief valve of the AC unit.  Can anyone comment on whether or not the tensioner can simply fail on it's own?  Could it be possible this is all I need to replace, and would anyone care to comment on a DIY or if the engine needs to be lowered to accomplish?

 

Thanks in advance!

[JFP in PA]

1 hour ago, flatsixing said:

All of my accessory and crankshaft pulley's seem to be in tact.  Wondering, if through some research, the loud pop I heard was the high pressure relief valve of the AC unit.  Can anyone comment on whether or not the tensioner can simply fail on it's own?  Could it be possible this is all I need to replace, and would anyone care to comment on a DIY or if the engine needs to be lowered to accomplish?

 

Thanks in advance!

 

Yes, like any other bolt or fastener, the tensioner can fail.  It is not a common failure, but it can happen.  Changing it out depends upon how you are equipped, it is difficult to get at without moving the engine due the proximity to the cross member, but I have been told it can be done.

[flatsixing]

Thanks JFP.  Looks like I am going to find out early next week.

[werkswell]

I have a 2009 Carrera S and with 27,000 miles on it the tensioner bolt suddenly sheared off in July (2016). My mechanic replaced the tensioner, belt and bolt but could not determine why it had happened.  All pulleys spun freely. Last week, December, 3000 miles, later the bolt sheared off again!  He confessed that he had used a standard bolt the first time (I was rushing him) and perhaps it was a hardening issue so this time he used an OE bolt from Porsche.  

Not a comforting situation.  I have owned many Porsches and never had this occur although its better than the time the (996) engine blew up as the IMS bearing failed.  FYI removing the broken bolt was "easy" the first time (enough showing to "grab" it) the second time required drilling and an "easy out" so the the exhaust system had to come off as well the rear bumper and even then the engine ad to be lowered just to access the broken bolt.  Once again I no longer trust my Porsche engine.

[JFP in PA]

Let me start by saying we have had a lot of cars similar to yours through the shop, and this is no where near a common issue; and is obviously not even in the same league with losing an IMS bearing.

 

Sometimes even hardened bolts have internal faults that cause them to shear off; Porsche does not require individual bolt testing on all fasteners on these engines.  It is also possible that the original bolt was not torqued properly, or that the replacement was over torqued, but we will never know the answer to that question.  As we do not know what kind of bolt your mechanic used, it is impossible to comment on what happened there.

 

This time, insist that your mechanic obtains the correct part number bolt from Porsche, and installs it to the recommended torque setting.  It is entirely possible that it will not happened again, but you have to start from a known position.

[Oldswede]

It’s not the bolt, the tensioner is frozen = check this = 

997 gen 2 drive belt Tensioner failure . | Porsche 911UK Forum

911UK.COM

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See the image below .. No.1 . T50 bolt that locates it. No.2 the pivot , it looks like a washer but isnt .. its a pivot . No.3 the 30 or 32mm nut you adjust it with , i forget which size off...

 

997 gen 2 drive belt Tensioner failure . | Porsche 911UK Forum

911UK.COM

---

See the image below .. No.1 . T50 bolt that locates it. No.2 the pivot , it looks like a washer but isnt .. its a pivot . No.3 the 30 or 32mm nut you adjust it with , i forget which size off...