active suspentioon on Q45

[capital Q]

i have a 91 Q45a it has 74,000 miles on i bought it w/@62,000 miles on it. its in great shape,but it doesnt take a bump or pothole well at all.i did a diagnostic on it(by flipping the N-H button back&forth 10X's) which came up as "all clear".i also measured the clearance according to the manual from center of axle to top of wheelwell and that seems tobe within specs.so then i emptied everthing out of the car measured it started it measured fliped it to H measured it and found that the car is actually higher when it is shut off than when it is turned on.is that normal? it came to me as a surprise. i thought it would have been the other way around. one other thing that happened last summer(this only happened 7or8 times)-on hot days if i drove for longer than50miles the active suspention would shut down-the dash light would come on and it felt like someone installed tires from a Big-Wheel on to the car.if anyone has any ideas on this problem i would greatly appreciate it. thanks, andy

[PalmerWMD]

Andy:With the "a's the shock towers lose their nitrogen charge after a while.The dealer will charge lots of $$ to fix this (cant blame 'em parts are expensive) but one member "texasoil" has a recharge ,method that has saved members tons of $$.

He is our resident "a" expert, if he doesn't find this post soon , you can go thru our members archive and email him.

Fred...

[texasoil]

Send me an email and I will send you back a few tips and things to look for. Sounds like you have flat accumulators (normal age/use cause it). Might also have low oil level in reservoir, which will trigger light.

[Q45tech]

On a used car [over 60k-75k] [especially a 12-13 year old one] the blowby [wear] causes the oil to darken thus necessitating filter changes at 3-4,000 miles......BECAUSE it is hard for owners to accept the 90 days with such low driving mileageUsing anything more expensive than Mobil 1 Synthetic doesn't make economic sense.

Just easier to change everything every 90 days.

A 91 Q45a with only 75k unbelievable?

[capital Q]

Q45tech it only has 74,311 miles on it !

[Q45tech]

What does mileage have to do with anything some of the worst ones I've seen were low mileage units where they were driven 5-6,000 miles per year.........they just couldn't bring themselves to change the engine oil more than once per year......it gelled from short trips not driving the car at least 20 minutes every time it was cranked. Same they never changed the active fluid as it changed color got dirty from seal wear accelerating the wear rates.

Mileage doesn't have much to do with the Nitrogen leakage either - the active system was only warranted for 4 years or 60k which ever came first!!!! If one set for 12 years and was not drive it would be bad also from rubber rot!Most actives did last for 6 years before the most sensitive owners felt the problem burt many didn't complain until it was out of warranty.....Infiniti was pretty good if you bought it new they would exchange the struts till 6 years................but we are speaking of a 12-almost 13 year old car here .....could have been built in mid 90 [a 91].

[Q45tech]

Check out 90-91-92 MB500/600 with the optional air [+ hydro] load level ride system thay all failed long ago.Most of the LS400 with optional air ride have had failure by now, the Lincoln Contenentals, others, all these systems fail and are expensive to repair............the LS400 struts are also $900 each.

Almost no knowlegable used buyer will make even an offer on old lux cars with air/hydro suspensions.