Engine 'Flaring' between gear changes.Argggh.

I have a brand new Barina/Aveo with the E-Tech II 16V engine (1.6ltr) and the engine flares between gear changes that is - to change gear- foot off accelerator , clutch in and the engine revs go up before going down , the amount of revs increase is directly proportional to the revs at the time of commencing changing :- ie. 3000 revs prior to change the revs will rise to 3300 before deacreasing , this makes changing an absolute PITA at times as the syncro's get loaded up and obviously this makes the change more difficult with second often finding 4th and third prefering 5th.
I've taken the car back to the dealers with a defect notice , they have tested the car and say that nothing is wrong and that the flaring is a "characteristic" of the car and that "all this model do it".
Wonderfull --I can look forward to prematurely worn synchros , gearbox , clutch and driveline components if I can't get this fixed--what a delight'.
My response to this nonsense is that I have farting characteristic if I drink to much beer and eat chilli but that dosen't make it alright in company and just because many others are similarly affected dosen't make it right for them either.
Has anyone else experianced this condition with thier cars when new/or not with any Aveo model atall - particularly the ones with the E-Tech II 16V 1.6ltr engine ?

Howzit,

I have the 1.5 SOHC and mine does the same thing from day one! Nothing to worry about, as far as I know all of them do it!

Will do some research and get back to you on why they do this...

how fast are you pushing in the pedal? our cars are drive by wire, and hydraulic clutches. so there is a delay in throttle response and the clutch acts quickly..

im not saying you are doing it wrong, but its two variables that would allow this to happen..

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Originally Posted by petrified.rabbit

how fast are you pushing in the pedal? our cars are drive by wire, and hydraulic clutches. so there is a delay in throttle response and the clutch acts quickly..

im not saying you are doing it wrong, but its two variables that would allow this to happen..

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No matter how slowly , or quickly for that matter , I change it still does it.
My first thought was that it is another "improvemnt' drive by wire idiosynchrosy however this one is appears to be drive by cable-(I think) however if it is drive by wire then the lag may be rectified by a vist to an auto sparks who knows what he's doing----and that might by like searching for a yeti-- :lol:
I'm thinking Stepper motor , TPS , AFM , just because they don't throw a fault code dosen't mean they're actualy working correctly but it can become an expensive (and often futile) excercise to play the "lets replace the sensors game".

http://img513.imageshack.us/img513/9...kengine.th.jpg
clik pic to enlarge

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Originally Posted by Fusion racingSA

Howzit,
I have the 1.5 SOHC and mine does the same thing from day one! Nothing to worry about, as far as I know all of them do it!
Will do some research and get back to you on why they do this...

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Thanks for that it's like having an itch I can't scratch that only starts when I drive the car. aaaaarrrrrrrrgh

http://img513.imageshack.us/img513/9...kengine.th.jpg
clik to enlarge

Drive by wire ????????????

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Originally Posted by BASHO

Drive by wire ????????????

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no

There is a nut (turnable by a small allen key) at the throttle body which hold the throttle opened at a slight angle when throttle is released fully. If that nut is too high, meaning the throttle open too much when throttle is fully released, it will cause this whinning of engine when clutch it. Becos too much air rush in. The closing of the throttle plate is stopped by the nut.

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Originally Posted by xiaogary

There is a nut (turnable by a small allen key) at the throttle body which hold the throttle opened at a slight angle when throttle is released fully. If that nut is too high, meaning the throttle open too much when throttle is fully released, it will cause this whinning of engine when clutch it. Becos too much air rush in. The closing of the throttle plate is stopped by the nut.

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That nut is to adjust the idle, if the car is idling fine, adjusting it won't fix the issue he has.

Could it be the O2 sensor? I've had problems with the engine revving up and down in neutral before and that fixed it...

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Originally Posted by MetroAveo

Could it be the O2 sensor? I've had problems with the engine revving up and down in neutral before and that fixed it...

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The symtoms you describe could also be , and usualy is , the intake AFM (air flow meter) so it's easy to see that when no sensors are out far enough to throw up a fault code or a CEL (check engine light) the problem becomes a bit harder to pin down , it could be :--

*Intake AFM (air flow meter).
*stepper motor.
*TPS (throttle position sensor).
*02 sensor/s.
*Flywheel position sensor.
*Intake vacuum sensor --(whose name I don't know).
*And if they all (GM Holden Barinas, AVEO8s) do it--inacurate basic throttle opperation programing.

Where no cel/mil warning light is present you would think that an accredited GM workshop/dealership would have someone with enough experiance to diagnose the problem--in this instance--obviously not. :evil:

I have given GM/Holden a defect notice along with notice that I will hold them liable for all damage requiring replacement or repair to consumeables not covered by warranty --ie clutch--etc along with all other normal warranty items which may be affected by this in event of premature wear and in perpetuity , this will now also include charges for my time and consumeables (stationery,secretarial time etc) expendeded attending to this matter.
GM/Holden are stating that this is a "characteristic" of this vehicle (Barina TK09 -I think Aveo8) the one with the E-TECH II 16V engine in it.
Be warned "CHARICTERISTIC" = a GMism for fault we won't / can't fix .
It is not a huge issue to me --just a fault which should be rectified.

What you are concern with the rpm is call progressive shifting. keeps the rpm so the rpm match the rotation of the wheels. Not like the old autos where you ram the gears in shifting into higher gear. if you learn to use the progressive shifting you will have a smoother ride when shifting to higher gear.

I mean the nut is blocking the throttle plate from closing completely. So after he remove his leg from throttle clutch in, plate never close completely, some air manage to go in, so explaining the flaring.

I knew it becos I purposely did this with my 285 degree camshafts to make sure engine doesnt dies when I clutch in due to low vacuum (which is a problem with high cams). It makes the engine flares when clutch in.

Mine intermittently does a similar thing. When I press in the clutch, the engine revs don't fall as they should. I drove a Focus which did the same thing. When I drove the Versa, the responsiveness was excellent and the revs fell immediately when the clutch was pressed in.

I don't know why it does this, but it doesn't always do it. Sometimes it's worse than other times. It definitely feels like the clutch is wearing faster than it should, and I think this might be partly why. My Lancer did the same thing and the clutch also seemed to wear faster than other cars.

I don't see any advantage to having the engine rev longer after you press the clutch in. When you shift into the next gear up, the revs will be lower, not higher... so it doesn't make any sense at all to keep the revs higher after clutch pressed in.

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Originally Posted by xiaogary

I mean the nut is blocking the throttle plate from closing completely. So after he remove his leg from throttle clutch in, plate never close completely, some air manage to go in, so explaining the flaring.

I knew it becos I purposely did this with my 285 degree camshafts to make sure engine doesnt dies when I clutch in due to low vacuum (which is a problem with high cams). It makes the engine flares when clutch in.

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On EFI engines, the throttle plate does NOT control the idle of the engine. It's controlled by the IACV. Unless you max out the IACV, the throttle plate will not control anything. If you close that plate completely, it can damage both the plate and the throttle body. That screw is not there to adjust the engine's idle, (this can only be done electronically, that I know of), it's there to maintain a degree of adjust-ability while components are assembled to keep manufacturing costs lower (precision manufacturing is more expensive, and would reflect in the cost of the vehicle/replacement parts).

Your surging problem (OP) is more than likely a slow IACV or a slow throttle stepper motor. If you don't have decent mileage built up, the issue will likely cure with time. If you're over 10,000 miles by now, I'd probably check further into it.

There is never a call to replace sensors randomly - this is what service garages do - they throw your money at the problem until it's fixed. Proper diagnosis of automotive malfunction went out the window with the advent of OBD systems. Get yourself a multi-meter and the specifications to test the sensors, and be a real mechanic.