Automatic Observations

[hortonds]

Having owned the Rover 75 for four years I'm astounded that it's taken me so long to find this out.

I've driven many automatics in my time ... usually if you need to get up to speed quickly on a motorway from a slip road: You put your foot hard on the accelerator, it drops gears, accelerates to close to the red line, goes up a gear and accelerates again etc.

In my Rover this works if you press the pedal about 3/4 of the way to the floor. But ... if I floor it then it changes down, accelerates to just before the red line and ... stays in that lower gear until I slacken off the accelerator and then goes up a gear.

Am I missing something?

[steve-45]

Are you in normal or sport mode ?

[hortonds]

Tried in in Normal AND sports mode ... same thing

[flying_pig]

At the end of accelerator pedal travel theres a kick down switch if you keep your foot down itll stay in lowest possible gear

[frankson]

If you want it to change up a gear slacken your foot off the throttle a bit.

[SD1too]

Originally Posted by flying_pig

At the end of accelerator pedal travel theres a kick down switch ...

Are you sure about that Mike? On a 75/ZT with ECU-controlled automatic transmission?

Originally Posted by hortonds

... if I floor it then it changes down, accelerates to just before the red line and ... stays in that lower gear until I slacken off the accelerator and then goes up a gear.

I think you have a problem David. Begin by carrying out a comprehensive engine service because an out-of-tune engine can have a dramatic effect upon the operation of an automatic gearbox.

Simon

[mileshawk56]

Blimey Simon Ive just said the same to Peter(scorpio) and honestly I wasn't peeping over your shoulder. Chris S

[hortonds]

Thanks for the reply SD1 ...
It seems to be running just fine, Diesel and no black smoke etc ... so before I go to any expense I'd like to know if it's "meant" to do this or if it's my car playing up.

[slovcan]

Originally Posted by hortonds

Thanks for the reply SD1 ...
It seems to be running just fine, Diesel and no black smoke etc ... so before I go to any expense I'd like to know if it's "meant" to do this or if it's my car playing up.

All the automatics I have driven - American, Japanese & German - have acted the same as each other. You use "Kickdown" for hard acceleration. Depending on your speed, it will downshift a gear at ~3/4 throttle or maybe a couple of gears at full throttle, foot buried in the carpet mode. In all cases you can induce an upshift by easing up on the throttle a bit. Or, in all cases you can keep your foot firmly on the floor and it will upshift automatically. This usually happens before redline - I would say on average 300-400 RPM below in the lower gears and sometimes 500-800 RPM shifting from 3 to 4 or 4 to 5.

I think something is not right in your case. Modern transmissions are computer controlled based on sensor inputs. The computer sends signals to the solenoids in the transmission that activate and trigger the shifts. Failed solenoids are a common ailment these days and are usually pretty easily accessible for replacement without major surgery - usually just dropping the pan and, sometimes, the valve body.

BUT, yours will shift, so I am doubtful of a bad solenoid, but not ruling it out. That leaves a sensor or transmission computer, maybe. Have you had regular transmission fluid changes done? This is essential even though some manufacturers say they are lifetime filled and sealed. That just ensures the transmission lasts through the 100,000 mile warranty. It does nothing good for the long term owner.

We'll need to do some research on your symptoms.

Edit: I had a think about it and now think it could well be a failing solenoid.

Cheers,
Glenn

[hortonds]

Many thanks Slovcan,
No ... I doubt in all of the 250,000 miles it hasn't had a single gearbox oil change ... maybe time