hello guys,

i have my xj6 2004 since 2 months now .
i have noticed things someone may help me to understand

at startup sometimes , steering wheel is hard to turn , then i switch off the engine , switch on again and it comes back normal easy to rotate ... very strange.

also my battery seems very low as sometimes i need to keep the key right position for 2 second for something to happen and engine to start .
i have refilled the battery with distilled water but i doubt maybe the battery is to be changed .

thanks if you have some comments or ideas

thierry

 

If your battery is giving you problems, replace it, the longer you wait you will harm one of your modules.
Here the heads up on the power steering system
Jaguar Technical guide:
Servotronic Power Steering


The Servotronic power steering system operates using

a conventional hydraulically operated rack and pinion,

equipped with a rotary valve and added electronics to control

the system’s hydraulics. This system provides the driver with

steering assistance proportional to the vehicle’s speed:

• with full hydraulic power assistance provided at low vehicle

speeds, for example when parking the vehicle, and

• a gradual reduction of hydraulic steering assistance as the

vehicle speed increases, allowing the driver a precise feel

of road contact.

The operating function of the Servotonic system is explained

below:

• Road speed data, as measured by the electronic

speedometer is transmitted to the FEM by the instrument

cluster, via the SCP bus.

• Using the variable assisted power steering (VAPS) curve

data stored within its memory, the FEM calculates the

amount of current needed to supply the VAPS solenoid,

which is an integral part of the Servotonic transducer.

• Based on the amount of current received from the FEM, the

VAPS solenoid controls the hydraulic reaction of the rotary

valve.

• This hydraulic reaction determines the amount of torque

(effort) the driver needs to apply to the steering wheel at

various vehicle speeds.

A further advantage of the Servotronic system is the fact that

the oil pressure and flow are never reduced and can therefore

be utilized immediately in emergencies, where sudden and

unexpected steering corrections become necessary.

The power steering pump is mounted to the engine and

is driven by the accessory drive belt. The pump provides a

constant flow rate of 7.5 liters per minute and has a maximum

pressure of 110 bars. The fluid reservoir incorporates a

10-micron internal filter to ensure cleanliness of the system.

 

George

thanks for this detailed answer.
i will change the battery and see if any improvement.

rgds

thierry

 

hello,

i replaced battery with a new one and problem is gone .
i have put a 95ah duracell maintenance free , perfect

thanks for advise

thierry

 

I'm glad it worked out for you. Thank you for the heads up.
George

 

Just read this thread and I'm hoping there may be a similar issue. I have a 91 XJS in fabulous condition but the steering is giving me some concern. I bought the car a few months ago and I'm just going through it before I register it. The steering system seems to have a flat spot on either end of the travel. It seems to work well and then it becomes much stiffer at the equivalent spots on either side of the neutral position. Seems ok going straight down the road but I wish it had more assistance at very slow speeds. At normal speeds the steering assistance seems to drop right out at the 2/3 position either way. Has a new battery and the fluid level is fine. Decent belt on the reservoir but not great. It is taught though. Any ideas?

 

I would like to confirm I had exactly the same problem with the heavy steering at start up. The battery actually died terminally 2 days later on a cold frosty morning. A new Battery fixed the problem.

 

The power steering on x350 is fluid driven, but is also electrically controlled so it has differing resistance at different speeds, i.e, at low speeds its nice and light, but at higher speeds it tightens up, so if the battery is low, the system doesn't have enough power and the "weight" of the steering isn't assisted. I think that show it works anyway, I have had heavy steering issues when my battery was low too.


As for the XJS, ( love them by the way ), I believe that is old school power steering, just pump, fluid and belt. I would check both ends of the steering rods, the wheel ends can seize up and are a common MOT failure, but sometimes, and especially with age, the ball joints at the rack end of the arm can stiffen up too.