Hi All,

My Missus 500C with dualogic has a(nother) possible issue. It drives fine and there is nothing noticeable other than the pump priming noise when you open the drivers door goes on ALOT longer. before it would run for like 3 seconds now it is closer to 10, it also makes the noise while driving more often. I assume it is something to do with the dualogic system as it often makes the noise after changing gear. Is it about to go bang?

There’s probably nothing wrong - pump priming time when the door is opened depends on how much pressure remains from the last time the pump ran. After a few hours it’s normal to have the pump run at least seven seconds. The pump runs to charge up pressure against the accumulator (a gas-filled sphere). Running for a shorter time than previously (ie the pressure reaching the limit sooner) would be a bad sign, as that would mean the accumulator had lost some of its gas charge.

It’s normal for the pump to run after a gearchange.

If you are particularly concerned, you might like to check the Dualogic fluid level (CS Speed fluid) in the reservoir underneath the foil heat shield. Four 10mm nuts secure the heat shield; there is little space to move it, but with an LED torch you should be able to see the level in the reservoir. There are small arrows/lines moulded into the plastic near the ‘neck’ about 2/3rds up the tank; there may also be a green paint line.

If the fluid was very low then pressure could take longer to build, but I doubt you would have sufficient fluid to perform gearhanges if that was the case.

-Alex

The fluid level should only be checked once the system is depressurised. It's not really a check and top up reservoir for the average user.
You can do this using the multiscan software or by disconnecting the pump and running through the gears in the most basic sense

chris red said:

Hi All,

My Missus 500C with dualogic has a(nother) possible issue. It drives fine and there is nothing noticeable other than the pump priming noise when you open the drivers door goes on ALOT longer. before it would run for like 3 seconds now it is closer to 10, it also makes the noise while driving more often. I assume it is something to do with the dualogic system as it often makes the noise after changing gear. Is it about to go bang?

Click to expand...

Doesn't sound right to me. The unit when new, the pump should run for around 5 seconds when opening the door and if you are stationary, it should be capable of around 4 gear changes before the pump activates - So N to 1, 1 to N, N to R, R to 1 (pump may activate here), 1 to N (or here).
There will be a margin or tolerance to be fair, so 5 to 7 seconds is acceptable. 10 seconds of pump priming on opening the door would to me seem at the upper limit.

I don't know the mileage of the car, but it may be that the accumulator or motor is now past it's best. You could also remove the battery and tray and look with a touch for any leaks!

If there are no visible leaks, then really it could go on like this for many 10 thousands miles before the motor gives up... but the pump motor will be wearing at twice the rate it needs to be

I suppose it depends on how old the car is and how many miles it has done. If your gonna tell me the car is 9 years old with 80K miles on the clock... with no leaks then it is probably just the natural progression of wear. If the car is 2 or 3 years old, then have it checked out.

The other thing that crosses my mind, is the age of the car battery and it's state of charge?
For example, a poor battery or a battery with a poor state of charge will exhibit a lower voltage, particularly when left over night.
Lower voltage means the pump motor doesn't spin as quickly and takes longer to prime the gearbox.
This wouldn't be the case when the engine is running though, as assuming the alternator is charging correctly the voltage will be lifted, even on a poor battery.

So perhaps remove the battery and battery tray - charge the battery up - and check for leaks with a touch while the tray is removed

The car is 8 year old with a 63,000 I think on it. The battery is originally, but Seems absolutely fine, no trouble starting the car. I've told her to keep an eye on it and any trouble changing gear or anything let me know ASAP. I have to rip half the car apart to replace/fix the heaterbox at some point so I'll have a look at it all then.