VT V6 auto issue

[slolux]

Ok, before I get flamed I have done some searching about the following problem and was after some advice/ideas.

My wife's VT V6 wagon has an intermittant problem while driving at cruising speeds which seems related to ambient temperature (when its hotter it seems to happen more).

When driving along normally the lockup in the converter will kick in at around 70 - 90 kms/hr, but at times you can feel the converter then unlock (feels like its dropping back a gear) after a few km's. There seems to be no reason that it happens and then the car will be doing around 2500 rpm for the rest of the trip (no doubt using more fuel).

No overtaking or increase/decrease in speed, just seems to happen when it feels like it. It usually sits at about 1700 - 1900 rpm when its behaving itself at 100km/hr.

Am I correct in thinking its the converter or could it be electrical? Roughly how much are we up for if that is the case? I realise that distance diagnosis can be difficult but any input would be appreciated.

Sorry for the long post.

[Ausmartin1]

Don't wish to sound flipant - but it like the old how longs a piece of string... it could be any of:
1) Pressure sensor board on Valve body full of crud / faulty
2) Loose connector / wiring break
3) Solenoid valve / Modulator solenoid valve related fault
4) Any number of seals leaking when hot.
5) Valve seperator plate worn, check ball issues.
6) Etc.

Don't think there us a an easy way to fix it without pulling it apart ...

Simply put, you need an experienced & honest tech to fault find and put it right, plus a number of preventative maintenance items including accumulator seals x3, Item 5 etc.

Or you can learn like I did, buy lots of books and replace in the past lots of bits $$, takes longer may cost the same, but hey I've had fun / hobby doing it - working on auto hydraulics.

If you like being on your back with auto fluid dripping on your head why you sort out all the diferrent size valve body bolts & torque & tighneting sequence! go for it, I always really appreciated all the fine work that is built into a modern auto now. - Don't forget to keeping everything hospital clean when working on it - If in doubt flush everything with new auto fluid, keeping your hands and tools spotless. Special assembly grease is avail to try to hold things in place while you reassemble.

On mine I've fitted all Pinless accuators from Sonnax - minimises leakage and gearbox now has fantastic R-D quicker shift time now when hot.
Also replaced the valve Separatior plate with two new clip in filters @ 40,000Km I was quite supprised at the wear by the check balls on this - guess mainly city driving doesn't help.
Will fit a new sonnax reverse boost valve next time I do a major service.

Wish you the best of luck to get it sorted, it's a very popular transmission you should be able to sort it out and GM trans's are normally really good and up there in reliability for standard 6's, for moded V8 - not 4L60E, So you are in luck already with it being a 6.

Best wishes,

Martin

[slolux]

Don't wish to sound flipant - but it like the old how longs a piece of string... it could be any of:
1) Pressure sensor board on Valve body full of crud / faulty
2) Loose connector / wiring break
3) Solenoid valve / Modulator solenoid valve related fault
4) Any number of seals leaking when hot.
5) Valve seperator plate worn, check ball issues.
6) Etc.

Don't think there us a an easy way to fix it without pulling it apart ...


I thought that this may be the case... I do enjoy fixing stuff so I may give it a go as I have access to a hoist etc.

Although the idea of just putting in a reco box is tempting........and easier in the long run I would think. Less satisfaction though!

Thanks heaps for your reply/ideas....have a good new year

tim