Xantia FDV hiss/power loss!

[cc101]

Hi all, meant to post this a while ago! When driving along normally I feel a slight dip in power as if the engine is braking, this only happens when you hear the FDV hiss, I presume this could be a load on the pump? Any suggestions as to whether this is normal, it's been doing it as far back as I can remember.

Cheers, Chris.

[Mandrake]

The only sinker Xantia I've ever driven (1993 1.9TD) exhibited the same behaviour - a slight hiss from the FDV whenever the pressure regulator switched to "cut-in" mode to top up the pressure in the hydraulic system, and a significant dip in revs, at least at idle.

Whether its "normal" I can't say. The old single output 6 piston pumps in the sinkers draw a lot of horse power from the engine when the pressure regulator cuts in as you have 6 pistons supplying the pressure regulator.

On the later 6+2 pumps only 2 pistons supply the pressure regulator so the load increase is much smaller (1/3 as much) when the pressure regulator cuts in and is barely noticeable. I would say what you notice is just a quirk of the design in a sinker.

[cc101]

Thanks Si, did the balljoints and driveshaft gaitors yesterday, my 5' scaffold pole came in handy!

Chris.