9000 tensioner problem?

We have just replaced the chains in my friends 1996 9000 Aero
Automatic. He is now suffering from a vibration at low revs which
smooths out to be unnoticable up the rev range. The chains were all
adjusted to TDC and the marks on the balance shafts and cams all lined
up, and were still lined up having rotated the engine a few times by
hand before we put the timing cover back on. We put a new water-pump on
and top engine mounts, replaced the two pulleys and belt, and
reconditioned the starter and alternator. I am wondering now about the
belt tensioner and would like to know how this goes bad and the effects
of it doing so please?
Does anyone else have any ideas to work on?
--

Richard Sutherland-Smith
19 Webb Road, Wanganui 5001,
New Zealand

Richard Sutherland-Smith wrote:

We have just replaced the chains in my friends 1996 9000 Aero
Automatic. He is now suffering from a vibration at low revs which
smooths out to be unnoticable up the rev range. The chains were all
adjusted to TDC and the marks on the balance shafts and cams all lined
up, and were still lined up having rotated the engine a few times by
hand before we put the timing cover back on. We put a new water-pump on
and top engine mounts, replaced the two pulleys and belt, and
reconditioned the starter and alternator. I am wondering now about the
belt tensioner and would like to know how this goes bad and the effects
of it doing so please?
Does anyone else have any ideas to work on?

Richard,

My experience is that these engines *normally* tend to vibrate quite a
bit at idle, especially with automatic transmissions when in drive.

If everything smooths out at higher rpm (just above idle) it sounds like
the balance shafts are probably OK. Are you sure that the vibes are
abnormally high?

Have you had an experienced SAAB mechanic look at it?

What sort of upper engine mount bushings did you install? I know from
experience that the urethane "performance" bushings increase the
vibration at idle severely.

BTW, I've never heard of a belt tensioner causing engine vibrations.

-Fred W

I can certainly confirm that my 9000 Aero engine sometimes vibrates a bit at
idle. There is variability of this vibration, which I believe is related to
additional variable load that the Climate control system (AC) presents. At
speed, this additional load is negligible, but may be substantial enough to
be noticeable at idle.

-Dima

"Fred W" <Fred.Wills (AT) SPAMmyrealbox (DOT) com> wrote

Richard Sutherland-Smith wrote:
We have just replaced the chains in my friends 1996 9000 Aero
Automatic. He is now suffering from a vibration at low revs which
smooths out to be unnoticable up the rev range. The chains were all
adjusted to TDC and the marks on the balance shafts and cams all lined
up, and were still lined up having rotated the engine a few times by
hand before we put the timing cover back on. We put a new water-pump on
and top engine mounts, replaced the two pulleys and belt, and
reconditioned the starter and alternator. I am wondering now about the
belt tensioner and would like to know how this goes bad and the effects
of it doing so please?
Does anyone else have any ideas to work on?

Richard,

My experience is that these engines *normally* tend to vibrate quite a bit
at idle, especially with automatic transmissions when in drive.

If everything smooths out at higher rpm (just above idle) it sounds like
the balance shafts are probably OK. Are you sure that the vibes are
abnormally high?

Have you had an experienced SAAB mechanic look at it?

What sort of upper engine mount bushings did you install? I know from
experience that the urethane "performance" bushings increase the vibration
at idle severely.

BTW, I've never heard of a belt tensioner causing engine vibrations.

-Fred W

My only experience with belt tensioner failure on a 9000 was growing noise
followed by a bang and overheating. Don't remember vibration.

Tom L.

"Richard Sutherland-Smith" <richard.ss (AT) clear (DOT) net.nz> wrote

We have just replaced the chains in my friends 1996 9000 Aero
Automatic. He is now suffering from a vibration at low revs which
smooths out to be unnoticable up the rev range. The chains were all
adjusted to TDC and the marks on the balance shafts and cams all lined
up, and were still lined up having rotated the engine a few times by
hand before we put the timing cover back on. We put a new water-pump on
and top engine mounts, replaced the two pulleys and belt, and
reconditioned the starter and alternator. I am wondering now about the
belt tensioner and would like to know how this goes bad and the effects
of it doing so please?
Does anyone else have any ideas to work on?
--

Richard Sutherland-Smith
19 Webb Road, Wanganui 5001,
New Zealand

"Hyperdog" <hyperdog (AT) maine (DOT) rr.com> wrote

My only experience with belt tensioner failure on a 9000 was growing noise
followed by a bang and overheating. Don't remember vibration.

Tom L.

My experience of the serpentine belt going was a bang followed by immediate

loss of power steering......

"Richard Sutherland-Smith" <richard.ss (AT) clear (DOT) net.nz> wrote in message
news:1c32da1c4d.Richard (AT) richard (DOT) ss.clear.net.nz...
We have just replaced the chains in my friends 1996 9000 Aero
Automatic. He is now suffering from a vibration at low revs which
smooths out to be unnoticable up the rev range. The chains were all
adjusted to TDC and the marks on the balance shafts and cams all lined
up, and were still lined up having rotated the engine a few times by
hand before we put the timing cover back on. We put a new water-pump on
and top engine mounts, replaced the two pulleys and belt, and
reconditioned the starter and alternator. I am wondering now about the
belt tensioner and would like to know how this goes bad and the effects
of it doing so please?
Does anyone else have any ideas to work on?
--

Richard Sutherland-Smith
19 Webb Road, Wanganui 5001,
New Zealand


Hi Richard,

my 9000 2.3 FPT had a really nasty vibration from the engine bay at idle for
about a week, which disappeared with application of power.

Took it straight to my local SAAB Specialist, and they couldn't find a
problem. Checked engine mounts, exhaust mounts and bolts, belt pulleys etc
etc.

It went away after a week, never explained it, and nothing has gone pop
since it went away.

Not a great help I know, but I would suggest you let her "bed in" or a few
hundred miles first.

Al