VZ V6 auto problems

[paroharo]

Hi crew, I've got a VZ Equipe wagon, Alloytech 170 with 4-spd auto. Had it from new and always been a great car. It now has 68,000kms and was most recently serviced in December 2008 at approx 62,000kms.
Lately a number of problems are rearing their heads all around the same time so I'm wondering if they're related.
I've checked out the FAQ and checked out all the threads in this section that sound like mine and there are some similar but none quite the same.
So here goes:

1. Service Engine Oil warning - I thought this was an issue but I have since read here that that is a common one that is just a software problem. Does that sound right?

2. Rough idle - once the engine has warmed up it idles rough (only just above 500rpm) in gear and out of gear.

3. In 4th gear, at 1500rpm, doing around 80km/h under load (ie going uphill) there is a hydraulic sounding "banging" or "thudding" that to my untrained ear sounds like the torque converter changing between different stages of lock-up as it strains up the hill. It's fixed by clicking back into 3rd gear or accelerating to get it to kick down to 3rd gear.
Does my torque converter theory sound plausible?

4. When accelerating under partial throttle, the engine seems to "stutter" or pause as it gathers revs. Once the revs build it's OK and if you floor the throttle it doesn't seem to happen. This was initially only happening when the engine was cold but is starting to happen once it's warmed up now too.

I was going to take it back to the dealer where it's still under extended warranty (coming up for 3yrs 9months old) but I don't think I can replicate these problems in the CBD of Adelaide and also by the time I get there the engine will be well and truly warmed up.

Any advice or info anyone could offer would be much appreciated.

Cheers,
Jon

[andyman]

ok to start with i take it the trans oil level is on the max mark after youve driven it around for say 10-15minutes? check it with the engine running, you can also check it cold with the engine running too,

if it isnt, top that up,

hmm does sound a bit torque converter-ish, check the fluid level, then ring the dealer you bought the car from and question them to see what they say, if the problem shows itself mainly when the cars cold, you may have to leave it there overnight if thats possible

[paroharo]

cool, thanks
so you can take the trans dipstick out with the engine running can you?
does it need to be in park or neutral?
I've checked it cold and it's ok but not once it's warmed up.
The reason I wasn't confident in the dealership service dude was cos he wasn't heaps sure over the phone, but if I write out my problem like I have here they might have more of a clue where to start when I take it in..

cheers,
Jon

[andyman]

cool, thanks
so you can take the trans dipstick out with the engine running can you?
does it need to be in park or neutral?
I've checked it cold and it's ok but not once it's warmed up.
The reason I wasn't confident in the dealership service dude was cos he wasn't heaps sure over the phone, but if I write out my problem like I have here they might have more of a clue where to start when I take it in..

cheers,
Jon

yeah to check the level it has to be running, cause if you pull the dipstick out when it turned off all the oil from the cooler, torque converter, inside the box etc, drains back into the sump and raises the level

[paroharo]

After discussing with my colleagues at work and narrowing down the options for the cause, we reckon it might be the throttle body..

The gearbox (inc converter) is fine under all other conditions, and the throttle is steady under the 4th-gear-1500rpm-80kmh-under-load conditions.

If the drive-by-wire throttle is dodgy, it might be sending conflicting signals to the box to kick down when it's loaded up a bit, and may be the reason why the throttle is stuttering under acceleration.

I'll put this to the dealer when I take it in, the best possible thing that could happen is there's a fault code up for the throttle which confirms all I think and it's as simple as that..

[andyman]

After discussing with my colleagues at work and narrowing down the options for the cause, we reckon it might be the throttle body..

The gearbox (inc converter) is fine under all other conditions, and the throttle is steady under the 4th-gear-1500rpm-80kmh-under-load conditions.

If the drive-by-wire throttle is dodgy, it might be sending conflicting signals to the box to kick down when it's loaded up a bit, and may be the reason why the throttle is stuttering under acceleration.

I'll put this to the dealer when I take it in, the best possible thing that could happen is there's a fault code up for the throttle which confirms all I think and it's as simple as that..

hmm if there was an error in the throttle actuator setup, it will set a flashing errors on the dash, and the car will enter safety mode and reduce performance,


they also run 2 actuator circuit so it can compare the two, and know if one is in error aswell,


in saying that though, if im cruising with the transmission in normal shift and the torque converter locked up, and press the pedal down a bit, it tries to use the engine torque instead of dropping back, it tends to make a grumbling noise as it tries to do it, i find if i punch the throttle get it to kick back and then use the power, makes it better