Dot Matrix Pressure Warning Message, Does this sound 'normal'?

Hi all

Please bear with me while I explain. When I got my XM (99T V6 24v), about the only thing not working properly was the height control lever. It would only ever go from 'Normal' to half way to High and half way to Low. The car went up and down, I assumed to its extremities. Spoke to a couple of people who know XMs locally and was told the height rod would need greasing at the ends.

After a moment of inspiration tonight, I decided to pop off the trim cover around the lever, gear stick, etc to check all was well. Immediately it was clear that the corrugated rubber gaiter around the height lever was not going down the channels at the end - instead it was curling under itself and then fouling the lever.

Chuffed with my quick, cheap fix, I decided to endulge myself with some full up and down action (I'm still alone in the XM here by the way!!). It finally went right up, then right down, the right up again, then right down again and then... Bleep and a message on the dot matrix saying "Pressure Warning" following by "Brake Pressure Loss". The STOP light on the dash also lit up.

Rather worried I sat wondering what to do - I wondered if it might need some revs to "pump something up". Sure enough, revs went from 750 at idle to a modest 1250-1500 with a light right foot and up she rose!!

Anyway, whilst I realise in daily life, even when checking you might not make it go fully up and down three times on the trot, but is it 'normal' to need to rev the engine a little to keep the hydraulics pumping - or are they completely separate.

Cheers

Keith - carliterature

PS - Now seeing how low it will go I can't get over it - there's barely half an inch of finger space around the front wheel wells! Impressive stuff

I would say that seems normal as the hydraulic pump runs off the engine I get the same message when I go from low to normal

Mine nearly always give a 'low hydraulic pressure' warning when I start from cold and doesn't go off untill I give it some revs, I found after some expermentation that it is in fact low out put from the pump, its not delivering enough fluid at tickover, but its OK in normal driving. If yours is normally OK, its probably as Craig says, the demand for fluid temporaly exceeded the supply.

Peter.N.

Don't forget that dropping the car to low is part of the procedure to depressurise the hydraulics, so you are effectively bleeding off all the fluid back to the reservoir. So it's not really a surprise that you get the HP low warnings if you are doing this in quick succession.

So long as the car is behaving correctly at normal height I'd not worry too much.
Had to do the same panel fix myself in the past, lack of care when refitting the panel by PO or garage.

regards
Dave

Hi Kieth and all .
Ive have the same symptoms on my 2.1 td when going up and down the suspension height range .
The warning always goes out after a few seconds .
Ihave just changed my accumulator sphere after noticing the clicking noise coming from the pressure valve (i think) but i had some strange symptoms before i changed it ,my brakes did not work very well when reversing ,after initial start up,had to stamp on the pedal and the car level seemed to change when waiting in traffic with the foot brake on.The first few times i drove the car after replacing the sphere i got a momentary stop light coming on but it almost immediatley went off ,now its ok.I still seem to get the feeling that the height alters when hanging on the foot brake . All else seems ok The cutting out problem seems to have gone away(THANKS PETER) after you reccomended changing the fuel filter .
M.O.T. soon wish me luck.
Best regards BoB

Hi Carliterature and All

Because the height control lever on my 3.0 V6 did not travel fully either way I was going to go under the car with the WD40 to free off the front and rear height linkages. Then I saw the little gem from Carliterature on the turned in ends on the sliding plastic trim on the height control. Mine was the same and you have saved me the joy of getting the car on axle stands and crawling under the car to spray all the linkages. Just think of the pleasure I would have gained from doing all that and then finding that it did not solve the problem.

Thanks

XMexc

Hi all

I've found since posting that as long as revs are kept to about 1500rpm it's fine - no message or sluggishness at all.

Please to have been of assistance to you XMExc too - probably my first and last self help guide!!

Keith

This post has been edited by carliterature on August 12, 2005 07:54 pm