Have you double checked spark plugs? How old and which are they?
2011 9-3 Aero XWD - acceleration issue
Hello everyone,
I have a 2011 Aero XWD 2.0T (manual gearbox) and I have a weird issue when accelerating and was hoping someone knows something.
The easiest way I can reproduce this is to drive on the highway with the cruise control set at 130kmh (80mph) in 6th gear. At this point I tap the breaks lightly, the cruise control turns off and I slow down to around 110kmh (70mph) and keep the speed constant there. I hit the cruise control switch and the car starts to accelerate normally back to cruise control speed and what happens is that during acceleration I can feel the car shuddering 2-3 times for a brief second with a soft thud sound each time while it gets up to speed.
Best way I can explain the feeling is that it's as if the rear diff engine breaks, as if two parts turning at different speeds are suddenly connected.
The car has had all the fluids changed recently (haldex, rear diff, transfer case, engine, gearbox, etc).
The car also has a stage 1 remap.
This thing happens sometimes, like when trying to accelerate a bit harder while doing something like 60mph in 6th. But if I trash the car around at 3k-4k-5k rpm or more the car works fine, no issues.
Any info is greatly appreciated.
I have a 2011 Aero XWD 2.0T (manual gearbox) and I have a weird issue when accelerating and was hoping someone knows something.
The easiest way I can reproduce this is to drive on the highway with the cruise control set at 130kmh (80mph) in 6th gear. At this point I tap the breaks lightly, the cruise control turns off and I slow down to around 110kmh (70mph) and keep the speed constant there. I hit the cruise control switch and the car starts to accelerate normally back to cruise control speed and what happens is that during acceleration I can feel the car shuddering 2-3 times for a brief second with a soft thud sound each time while it gets up to speed.
Best way I can explain the feeling is that it's as if the rear diff engine breaks, as if two parts turning at different speeds are suddenly connected.
The car has had all the fluids changed recently (haldex, rear diff, transfer case, engine, gearbox, etc).
The car also has a stage 1 remap.
This thing happens sometimes, like when trying to accelerate a bit harder while doing something like 60mph in 6th. But if I trash the car around at 3k-4k-5k rpm or more the car works fine, no issues.
Any info is greatly appreciated.
1 - 14 of 14 Posts
Spark plugs are NGK, can't remember the exact model, and they're less than 6k miles old.
Sorry for the late reply, I had to dig through the service history, they're NGK 5542 PFR6T-10G, they have about 7k miles on them.
I still start with spark plugs, they are cheaper than coils etc.
It could also be the clutch starting to slip. 6th gear pulls are hard on the drivetrain.
Honestly now that you mention this and thinking about how the car feels you might be right, it does feel like two dry surfaces spinning and losing grip.It could also be the clutch starting to slip. 6th gear pulls are hard on the drivetrain.
It's likely that the clutch was getting worn, and when you replaced the plugs, the extra power finally overwhelmed the clutch.Honestly now that you mention this and thinking about how the car feels you might be right, it does feel like two dry surfaces spinning and losing grip.
I personally try to avoid hard any acceleration in 6th gear not just in this car, but any car. I usually downshift to 4th and complete the pass and then shift back in to 6th for cruising.
I went to the garage again today, took the car out for a drive and we've come to the conclusion that the issue is definetly something mechanical (probably because of the increase in torque?).
We reverted the stage 1 remap and now the car is stock again and no more issues. Also I noticed that the slight vibrations I was feeling in the clutch pedal and gear shifter at certain RPMs is gone now.
So I guess it's either a bad remap or the clutch/flywheel can't handle torque increase?
We reverted the stage 1 remap and now the car is stock again and no more issues. Also I noticed that the slight vibrations I was feeling in the clutch pedal and gear shifter at certain RPMs is gone now.
So I guess it's either a bad remap or the clutch/flywheel can't handle torque increase?
Yes, it sounds like the clutch/flywheel can't take the additional power. You will need to upgrade the clutch to accommodate the additional power. I'm not sure how much power the stock clutch can take before it starts slipping.I went to the garage again today, took the car out for a drive and we've come to the conclusion that the issue is definetly something mechanical (probably because of the increase in torque?).
We reverted the stage 1 remap and now the car is stock again and no more issues. Also I noticed that the slight vibrations I was feeling in the clutch pedal and gear shifter at certain RPMs is gone now.
So I guess it's either a bad remap or the clutch/flywheel can't handle torque increase?
In my experience with VWs, the stock clutch is pretty much at capacity with stock power levels. Any tune on those cars will require an upgraded clutch.
It's not the stock clutch and flywheel, from what service history I have from the previous owner he replaced them about 25k miles ago. I don't with what brand but I suspect he got the cheapest he could find.
That could definitely be a factor. In reality though, I haven't been able to find reliable information on how much power the stock clutch can take in either the 2.0 or 2.8 cars.It's not the stock clutch and flywheel, from what service history I have from the previous owner he replaced them about 25k miles ago. I don't with what brand but I suspect he got the cheapest he could find.
Like I said in my experience with VWs, brand new GTIs with stage 1 tunes were able to overwhelm the stock OEM clutch on cars with <10K kms on them. So the previous owner may have went with an OEM clutch, but if it can't handle the additional power from the tune it will slip.
Perhaps a bit early to tell but I had the stage 1 remap done at a different place today and the acceleration issue seems to be gone, the car runs fine and pulls like it should. I think the initial remap I had was done incorrectly and the ECU was hitting some torque limiters (not sure how to explain it better since I'm not familiar with this stuff).
1 - 14 of 14 Posts
SaabCentral Forums
SaabCentral forum the most comprehensive Saab resource on the internet. Join our discussions on the Saab 9-3, Saab 9-5, Saab 900, Saab 9000 and all other Saab models, choose your forum.
Full Forum Listing
Recommended Communities
