GTS Cam broke
02-05-2012, 12:24 PM
#17
Don't know the answer to that Ali. I think I heard that it was done before he took delivery of the car though.
02-05-2012, 12:40 PM
#19
Archive Gatekeeper
Rennlist Member
Rennlist Member
Bummer, I feel your pain- know what it's like to coast to the side of the road with an unhappy engine....
On the tensioner, how far into the tensioner body is the adjusting screw turned? Just wondering about how tight the belt was- I'm sure the belt tension was in spec but I wonder about the (de)tensioner's ability to (de)tension at high engine temps/rpm.
At least if your engine were a person, I would say that at least he died doing something he loved: 140 mph.
On the tensioner, how far into the tensioner body is the adjusting screw turned? Just wondering about how tight the belt was- I'm sure the belt tension was in spec but I wonder about the (de)tensioner's ability to (de)tension at high engine temps/rpm.
At least if your engine were a person, I would say that at least he died doing something he loved: 140 mph.
02-05-2012, 12:50 PM
#20
Bummer, I feel your pain- know what it's like to coast to the side of the road with an unhappy engine....
On the tensioner, how far into the tensioner body is the adjusting screw turned? Just wondering about how tight the belt was- I'm sure the belt tension was in spec but I wonder about the (de)tensioner's ability to (de)tension at high engine temps/rpm.
At least if your engine were a person, I would say that at least he died doing something he loved: 140 mph.
On the tensioner, how far into the tensioner body is the adjusting screw turned? Just wondering about how tight the belt was- I'm sure the belt tension was in spec but I wonder about the (de)tensioner's ability to (de)tension at high engine temps/rpm.
At least if your engine were a person, I would say that at least he died doing something he loved: 140 mph.
02-05-2012, 01:27 PM
#21
Addict
Rennlist Member
Rennlist Member
Sorry to hear it Richard.
As the others mentioned, bright side is that you now have the cam options.
Sean has the car so at least you know the GTS will be back on the road soon!!
Let us know as things progress!
As the others mentioned, bright side is that you now have the cam options.
Sean has the car so at least you know the GTS will be back on the road soon!!
Let us know as things progress!
02-05-2012, 01:41 PM
#22
Nordschleife Master
Sorry to hear Richard!
I got your email this morning and will respond soon.
When I read your first blurb about the light etc. I instantly thought bet he was running a contitech belt. Sean's post confirmed that.
I got your email this morning and will respond soon.
When I read your first blurb about the light etc. I instantly thought bet he was running a contitech belt. Sean's post confirmed that.
02-05-2012, 01:55 PM
#23
Drifting
Wow, for the few GTS that are out there, it sure seems like they have lots of issues.
I understand Bruce's explanation in post #2 which sounds about right.
RDK/Stick, you are lucky that you were close to Sean and at least the car is in good hands now.
Lets hope that no pistons are cracked and that you can get away with just a valve job and new cams.
The cheap way is to replace the one cam, check for valve damage. You can always do more later, Or do a full top end, valve job and big cams now.
This also depends on how busy Sean is and how long you will have to wait, Oh Ya and a big difference in price.
I think you should use the week to think about it.
I understand Bruce's explanation in post #2 which sounds about right.
RDK/Stick, you are lucky that you were close to Sean and at least the car is in good hands now.
Lets hope that no pistons are cracked and that you can get away with just a valve job and new cams.
The cheap way is to replace the one cam, check for valve damage. You can always do more later, Or do a full top end, valve job and big cams now.
This also depends on how busy Sean is and how long you will have to wait, Oh Ya and a big difference in price.
I think you should use the week to think about it.
77Tony
02-05-2012, 02:37 PM
#26
Rennlist Member
Sorry to read about this- is it my imagination or is it just one tale of woe after another at the moment? Fires, camshaft failures, crashes, white hot cats- crikey- I guess the next round of TBF failures is just around the corner.
We do not usually read of this type of failure on the 32V motors- will be interesting to know if Sean can find the root cause. If I read the photos correctly then the shaft snapped completely at the sprocket line.
Makes one wonder if we are all destined to have a major failure sooner or later when we own these things. Guess we just have to enjoy while we can as I did today.
Richard- hope you are back on the road soon.
Regards
Fred
We do not usually read of this type of failure on the 32V motors- will be interesting to know if Sean can find the root cause. If I read the photos correctly then the shaft snapped completely at the sprocket line.
Makes one wonder if we are all destined to have a major failure sooner or later when we own these things. Guess we just have to enjoy while we can as I did today.
Richard- hope you are back on the road soon.
Regards
Fred
02-05-2012, 03:53 PM
#27
Rennlist Member
Thread Starter
According to the records I got with the car the belt was replaced 1 year and 2000 miles before I got the car. I did have the tension checked as soon as I got it 3 years ago. I remember it was at 4 and the tensioner was loose. The car had 46K on the clock and now has 62K. The belt had 4 years and 16K on it.
02-05-2012, 04:35 PM
#28
Three Wheelin'
Does the records say that the cam gears were taken off by any chance?
There is a possibility that when they did the belt change the mechanic used the cam bolt instead of the big hexagon shaped washer to align the drivers side cam gear for the new belt. If the belt was changed at TDC, the drivers side cam gear should rotate clock wise looking at the front of the engine (not seating at the drivers seat, OK).
To bring it back into position for the new belt you have to rotate it counter clock wise. If he used the cam bolt to rotate the cam gear counter clock wise to bring it back into position, the CCW force could have slightly loosened the bolt. This is of course my experience on a S4 with S4 cams, I know the GTS cam profile is different, but I suspect that they rotate in the same direction once the timing belt is off at TDC.
I experienced this on my S4 when it was my first time working on it or any 928 for that matter. I did not have a big enough wrench to use the big hexagon shaped washer to bring the cam gear into correct position for the new belt, so with a 17 mm socket I used the actual cam bolt to rotate the cam gear CCW. Sure enough the bolt made a tick tick sound, which indicated movement.
There is a possibility that when they did the belt change the mechanic used the cam bolt instead of the big hexagon shaped washer to align the drivers side cam gear for the new belt. If the belt was changed at TDC, the drivers side cam gear should rotate clock wise looking at the front of the engine (not seating at the drivers seat, OK).
To bring it back into position for the new belt you have to rotate it counter clock wise. If he used the cam bolt to rotate the cam gear counter clock wise to bring it back into position, the CCW force could have slightly loosened the bolt. This is of course my experience on a S4 with S4 cams, I know the GTS cam profile is different, but I suspect that they rotate in the same direction once the timing belt is off at TDC.
I experienced this on my S4 when it was my first time working on it or any 928 for that matter. I did not have a big enough wrench to use the big hexagon shaped washer to bring the cam gear into correct position for the new belt, so with a 17 mm socket I used the actual cam bolt to rotate the cam gear CCW. Sure enough the bolt made a tick tick sound, which indicated movement.
02-05-2012, 06:12 PM
#30
Three Wheelin'
everything lined up because the belt didn't jump any tooth. The drivers side exhaust and intake cam stopped rotating after the exhaust cams nose broke, but the drivers side cam gear along with the crank and passenger side valve train kept on rotating with the belt still intact.