Mike Floutier

Good news, it's fixed!

I took it to my mechanic who listened as I simulated the noise and he said; "lower arm rear (No. 2) bush, I can feel it knocking here".

So I bought the bush but couldn't remove the old one from the carrier bracket so I bought a new carrier bracket thinking it would slip in fairly easily - haha.

Ended up taking the two new parts to said mechanic for him to press in - he only wanted a bottle, good chap that he is.

So I have just fitted the bracket/bush and as you can imagine I was a little nervous when simulating the problem but highly rewarded by a smooth, silent response when mounting a kerb at 90 degs. This compared with the previous gun-shot noise I was getting.

The puzzle remained as to what was actually causing the noise (in view of the negative result to the balsa wood test - above) but hey, what do I care!

The real clue that had me keeping this bush as the no. 1 suspect was the fact that the noise would change according to the steering position. If you study the geometry of the lower arm together with the change in direction of the forces acting on it that follow steering changes it's easy to see that on one lock the force on the No. 2 bush is at maximum and on the other lock it is nearly zero.

Many thanks to everyone, especially Luke, for your encouragement, as usual I'm not sure I would have got this far or saved as much money without your help.

Kind regards,

Mike

Thanks Luke,

Well I've got somewhere in terms of eliminating things:

1. The balsa wood test was negative - it was slightly compressed but NOT broken and the noise was the same (no damping by the balsa)

2. I tried setting the absorber damping to max on the offending side (instead of min) but this made no difference.

3. I removed the ARB/Sway bar link BUT the noise remained.

This afternoon I'm taking it to my favourite mechanic and see what he says - after all he was the first one to point it out when he was listening to my bearings.

Will let you know....

Regards,

Mike

Thanks Luke, quite a few people have suggested the sway bar links but the noise is so substantial (a real heavy knock) I've tended to dismiss it.

The other reason for not suspecting the links is that the noise is greatly increased under braking and I don't think they would be affected so dramatically.

I recently tried to remove the lower ball joint assembly (to see if I could). When putting some force on the bar to undo the joint's nut I noticed that the rear portion of the lower arm moved very close to the suspension subframe - Remember they are only 1/4 inch apart at rest.

My feeling is that, if the No. 2 bush is so slack as to allow this movement with just this effort, then the force of braking must bring those two parts so close together that any vibration - whether it be a pothole, a kerb, my previous warped disc or just a bumpy road - will inevitably result in the lower arm knocking/hammering/vibrating against the subframe.

I love your idea about the bullet cam Luke but my balsa wood arrived in the post this morning so I will be using that.

Will let you know how it goes.

Regards,

Mike

Interesting that you should mention the strut FG, I assume you have air-ride since you mention it leaking.

As you may know from another thread, I am fixing a problem with my air-ride suspension at the moment. A fault had caused it to default to a failsafe position of max height and max damper hardness. As a temporary solution I pulled the 20amp air-ride fuse and manually adjusted the ride height to normal and the absorber damping to minimum.

I am wondering if the minimum damper setting is contributing to this noise. I've thought about it though and it doesn't add up as eg. it would affect both sides and not just the left.

My money is still on the No. 2 lower arm bush simply because - a) it looks rotten and has a lot of movement, and B) When driving slowly at a kerb the noise increases slightly on a small right lock but disappears on a left lock. If you look at the geometry of the left arm you can see that right lock increases the force acting on the No. 2 bush whereas left lock moves the force away from the No. 2 bush but towards the No. 1 bush. This would explain this change in the clonking symptom.

Does this hypothesis make sense?

Also, you may have seen in reveiws of this model that they mention "unseemly clonking on encountering large potholes". Well I've looked closely at the No. 2 bush area of the lower arm and the design means that there is only a 1/4 inch gap between the lower arm itself and the suspension sub-frame it's bolted to. Not sure but it looks very easy for a small amount of movement here to produce clonking - especially with a worn bush.

My plan is to insert a suitable piece of hard balsa wood into this gap and go back to driving the car gently against a kerb. I will observe, 1. What happens to the clonking, and 2. what happens to the balsa wood.

"Another fine theory", I hear my wife saying - hehe

Thanks VB,

The truth is that I still don't really have a firm pointer towards diagnosing the cause of the clonking.

However, I'm encouraged by your advice and since this ball joint takes the entire burden of the road's undulations before sharing it with the rest of the suspension, I have decided is that (since I intend keeping the car for a further 200k miles +) it makes sense to replace it as I will probably have to replace it sometime anyway, so why not now?

As ever I will keep you posted.

Kind regards,

Mike

I'm still struggling with this so I'd like to post a little more on the symptoms so perhaps someone can help me track down the culprit. I've read all there is on the sites on these suspension noises and so far I've heard that every single part can cause the problem so please hear what the symptoms are and help me think through how this is happening.

OK, apart from a general increase in road noise being transmitted into the body what I have is this:

A.

1. A loud heavy knock/clunk - coming from the left front.

2. In normal driving I get this when going over a pot-hole.

3. To get a better idea I purposely drove the car at 90 degrees into a kerbstone (4 1/2 inches high) VERY slowly. This reproduced the hard knock sound perfectly. (only on the left wheel - if I did it to the right it was fine).

4. I then did the same thing but with the steering wheel turned one revolution left and then right. ie. tire approaches kerb at 90 degs. (rather than car approaches....). With the right turn the noise is slightly worse. With the left turn the noise disappears. I repeated this several times to be sure.

B.

1. Driving over a corrugated surface eg. cobblestones it's very noisy.

2. When doing this, if I brake, the noise is greatly amplified.

So, what do you think it is and why? Bear in mind the car has done 230k miles.

Thanks

Mike

Thanks Jon, I did wonder about the sway bar links. I've changed the sway bar bushes but they old ones were in perfect contition so I guess I forgot about the links.

I'll have to give them a wiggle and see how much movement there is, being in England the left side is on the bumpy side of the road so I'd expect them to go first.

Will let you know how it goes.

Regards,

Mike

Ok, having ordered the discs I have a few days to wait so I couldn't help tinkering. I removed the knuckle and hub from the lower arm to get a good play with the lower ball joint and track rod ball joint - both seem perfectly tight and full of grease.

Having re-checked the other bushes, I reassembled and decided to to find a suitable pot-hole to experiment with. Since I have a lot of noise (banging and bumping and general road noise) coming from the left front I thought I'd try the pot-hole at very low speed - thus ruling out the discs and tires.

It was obviously the wrong shape of pot-hole because it behaved fine on both sides. Now because I KNOW there is a problem with the left front suspension I thought I'd try driving the car very slowly into a kerb stone at 90 degrees (they are only about 4 inches high over here so not as crazy as it may sound). I was immediately rewarded as the left side would yield a gun-shot whereas the right hand side behaved perfectly.

Now which part of the suspension is causing this do you think?

With this noise I'm expecting to find something loose or a bush decomposing but it all looks fine to me.

I think I'll get my technician to have a look, he's supposed to good with suspension issues.

Will let you know how it goes.

Regards,

Mike

Thanks Landar,

I've had a chat with a local technician who says it definitely sounds like the discs. He says that it's not worth paying any attention to the disc runout reading in his experience when the symptoms are like this.

What I'm going to do to confirm this is to buy new Lexus discs and see what happens - I'll have to replace them sometime anyway so if the problem is still there with the new discs I can go back to the drawing board.

Will let you know how it goes, it will certainly be interesting if (within spec.) discs are causing this severe vibration.

Kind regards,

Mike

PS. I think the old discs (like the tires) were cheapo ones so maybe this is a lesson for me.

Ok first a bit of background. The car is 8 years old with 225,000 miles on the clock. No work done on suspension/steering except a new nearside hub/steering knuckle a few days ago. Oh, I also just replaced the anti-roll bar (sway?) bushes a few days ago. All the bushing and joints are original. Had 4 new cheap tires fitted about a week ago. I've checked the rotors for runout and they are both below 0.02mm (ie. within spec.)

The symptoms are:

1. A steady vibration felt through the seat and steering wheel at all speeds - it seems to make me feel sick/nauseous.

2. When braking, this vibration increases markedly and at some speeds sounds like a machine gun - varies a lot according to speed (when braking)

3. This vibration is felt and seen in the steering wheel BUT NOT at all through the brake pedal.

4. I'm getting a lot of noise into the car through the front suspension - eg. bumps and small pot-holes, especially at low speed, are very noisy.

5. I checked the radial runout on the new tires and got around 1.5mm (0.06"). Very obviously mishapen on visual inspection when spinning.

I've put a bar on all the bushes to check for movement but don't see any. The EXCEPTION is the rear bush on the lower arm which is very easy to push and has lots of movement (is this normal?)

I'm a bit stuck to know what to do next.

I wonder if it may be the combination of the mishapen tires and the soft lower suspension arm rear bushing causing the whole thing to vibrate (made worse by braking) but I don't really have a clue.

Can anyone throw any light on this?

Many thanks.

Mike

Ok, I didn't fancy taking out the rear seats and rear trim tray etc, etc to get at the absorber damping actuators so I decided to try out adjusting them by applying battery voltage to the relevant pins on the air-sus ECU plugs.

This worked well. I tested the idea on the fronts first as I knew that I would be able to verify the results by removing the actuator and checking it's new position. Having done that successfully I did the rears and was rewarded by a very observable change in the ride damping - ie. SMOOOOOTH.

So, I have the ride height and damping back to where I want it BUT there are two problems:

1. No anti-dive/squat/roll etc. I can live with that as I'm a very gentle driver, and

2. I have to leave the air-sus 20A fuse out because if I put it in,(I'm guessing) the ECU will again respond to whatever problem it's sensing, that presumably still exists, and simply undo all the manual adjustments I've made - ie. the ride height will skyrocket and the dampers will default to superhard. Problem with leaving the fuse out is that it stops the ECU sending signals to the headlight levelling ECU so no headlight levelling.

I guess I could always do the same thing and adjust the headlights manually to a satisfactory position and pull the fuse on that system as well - to hopefully get rid of that irritating dashboard warning.

Finally I'm left with trying to find the problem that triggered the ECU to default to the "failsafe" settings. What have I left to check that could be causing it? There are two things I suspect in the air-sus ciruits, 1. connector deterioration and 2. water ingress.

However, on the plus side, many parts are ruled out of the equation as by now I've done a lot of testing. The following components and associated circuits are ok - ie. have been tested for continuity in their complete circuits and have been tested in operation.

1. Compressor - works ok but I'm wondering about the terminals RM+ & RM- at the ECU and Compressor. They monitor the current flow to the compressor watching for abnormalities.

2. Exhaust valve - works fine.

3. Ride height control valves - all 4 let air in and out and remain closed when they should.

4. Absorber damping actuators - all 4 work fine.

5. Ride height sensors - another slightly grey area; all 4 sensors have been test and work ok. The circuit for the front sensors has continuity but I've yet been able to test the rear as the wiring diagram doesn't make sense and so I will have to resort to physically checking the relevant wiring for color-coding

So this leaves me with several possible areas that I've not even considered yet:

1. Skid control ECU input - surely if the Skid Control was bad then wouldn't it report itself, I don't know?

2. Steering sensor.

3. Absorber control switch.

4. Ride height control switch.

5. 2 seperate inputs from engine and ECT ECU.

So these along with previously mentioned:

6. Compressor monitoring circuit.

7. Rear ride height control sensor wiring.

When I was looking for the exhaust valve connector, (to test the exhaust valve) I unplugged it and water streamed out of the end of it's wiring's protective plastic shield. I think this water gets in when the valeting service squirt their high pressure water at the front of the car. It must hose in through the hood grille and somehow find it's way into the plastic shielding. Because the compressor monitoring wiring must be in this area too, I think I will start there.

Will let you know how it goes.

Kind regards,

Mike

Ok, back from church and flushed with yesterday's success I decide to have a go at the absorber damping as it's still just as hard as when the rear rose up like a dragster.

The front actuators came off in a few minutes and all the resistances were fine. I then twiddled it to see what it was set to currently and out of the 9 settings 1= soft, 9 = hard it was on 9, no wonder it was so hard.

Any I twiddled it back to 3 and lo and behold it's back to nice soft suspension. Ten minute job.

Now for the rears. I think that will take longer as they say that you have to remove the seats etc first. Maybe I'll leave that for next week.

This is wonderful progress, thank you Lord! And thank you guys for being there. I'd never attempt this stuff without the Forum.

Regards,

Mike

Ok, I'm starting to make progress here.

Main thing is that I've finally found the Short Connector - for some reason it doesn't change sides with the ECU from RHD to LHD, that threw me. Anyway, I found it on top of my drivers junction box (passenger J/B for all you LHDers).

I did the shorting as described in the manual and soon had the ride height levels back to normal.

Not only is this a relief but it proves that the height level control valves are all working and also the compressor and the exhaust valve.

Before rejoining the short connector I once again pulled the air-sus 20A fuse to avoid the same thing happening again.

Ok, as I said, it's a relief to be back at the right height. However, I had expected that the very hard ride that I was also experiencing would also go away - NOT the case.

If you remember, we agreed that a logical "failsafe" response to a failed sensor/(circuit) would be to default to maximum ride height so as to cope with varying loads etc. However, if you think this through further, it also follows that, to avoid problems with rolling, squatting, bouncing etc, (ie. something the system is design to do), the "failsafe" response would also have to include ramping the absorber damping up to maximum. This may well acount for the remaining hard ride.

My next plan is to try to:

a) Find out what the absorber damping is currently set to, and

B) Manually soften the setting - presumably by applying battery voltage to the actuators in reverse order to the hardening sequence specified in the manual.

Finally I need to discover what is causing this "failsafe" scenario to operate and remedy it so I can return to automatic control.

As usual, any ideas are welcomed.

Regards,

Mike

Many thanks CuriousB, I can't tell you what a relief it is to talk to a thinking person about this.

1. I agree about concentrating on the rear but will test the front sensors in high and low positions (on car) to establish that they (and the other bits involved) work ok - ie. the front rises and falls.

2. You mentioned the air valve servos being stuck open. Good point but since there are 2, one for each side, they wouldn't have both failed simultaneously.

3. I see what you are saying about the POT. what I've done is to set the POT link rods in extreme HIGH and then LOW positions and restarted the car each time. There was no response so it seems the POTS are ok. HOWEVER, I want to check the voltage at the suspension ECU and the continuity of the relevant wiring as the sensor CIRCUITS seem to be implicated (as you agree). My problem is that I can't locate the ECU even with the help of the manual - do you know how to find it?

Also I would mention that the only problems I have had with this car have been caused by electrical connectors needing cleaning (throttle position sensor AND igntion coil) so I'm cleaning every connector I come across.

4. I agree that the high rear position is most likely a "failsafe" response by the ECU to a lack of sensor input - it would be the only rational response.

I plan to test the exhaust valve as soon as I can get a connector for it (can't access the contacts without one, it's to remote).

I also interested to know if there are seperate air valves for filling and venting the shocks or whether the same one performs both functions - if there is only one for both then we know it works as the shocks are being filled but not vented. The lack of venting could be the exhaust valve (as mentioned).

I do need to get access to the ECU though and this is my main help request at this stage.

Many thanks for reading all this and for all your thoughts.

Kind regards,

Mike

PS I should also mention that I've now disabled the system by pulling out the 20A fuse in the driver's side junction box. This stops the compressor from continuing to overload the rear shocks BUT it also shows that the whole system has no leaks as it's been dieconnected for a couple of days now.

Later on... I checked the wiring diagram for the height control valves and there is only one valve for each strut that obviously handles both inflation and deflation. Therefore if it can inflate (which it can) then it can deflate, thus ruling out the height control valve circuit.

My 2002 LS430 has always behaved well and has reached 225,000 miles.

However a few days ago without warning the rear of the car rose up leaving a good 6 - 8 inch gap between the tire and wheel arch - same on both sides; the front stayed where it was. The dashboard message was "Height Hi" and the red warning triangle came on. The ride became bouncy and bumpy.

I read all the forum reports on this. It seems fairly common and the usual outcome is that one of the height sensors has to be changed (a $400 potentiometer - often 2 or more!!)

I removed both rear sensors and tested them. They were both fine - indeed they were spotlessly clean inside. I also tried the connecting links in high and low positions (on the car) but there was no response.

The compressor still works but I have now disabled it by removing the 20A fuse as it would still try to fill the system occaisonally causing the ride to become even worse and eventually some air being blown off via what I assume is a safety valve (not sure if it's in the struts, guess it must be)

I'm not sure how to proceed. Can anyone help me with this?

Regards,

Mike

Hi all,

I've had my engine light on for a while now because of PO1651 and I'd like to do something about it as:

1. It doesn't look good to my customers - I'm a professional driver, and

2. If the valve is open when it shouldn't be - ie. all the time the way I drive - this may be why I'm getting poorer gas mileage.

So far, both the problems I've had on this 200,000 mile car have been solved by cleaning up the relevant multiplug (throttle pedal position sensor & ignition coil).

According to the manual, I need to do quite a bit of dismantling to remove this VSV. I'm wondering if it's possible to get at the multiplug without all this dismantling. Does anyone know or has anyone got any experience of this problem?

Kind regards,

Mike

Thanks, I'm looking forward to doing it - it's always fun doing stuff for the first time.

Thanks DC!

Thanks guys,

Ok, I did that and hey presto they are now undone!!

Next questions:

1. Do you need a special "gun" to fill with new fluid or can it be done just using the bottle it comes in, and

2. What is the recommended fluid?

Many thanks,

Mike

Thanks DC, I've just got to find out what PB blaster is now, I've not heard of it over here - lol!

Mike

Hi,

I want to change my diff. fluid but I can't get the drain/fill plugs to undo. I could simply put more pressure on the already long bar that I'm using but I'm concerned about damaging something.

What should I do to get them undone?

1. Should I heat them?

2. Am I likely to do any damage by increasing the pressure on the bar I'm using?

Help!!!

Kind regards,

Mike

Thanks everyone,

I think I'll just order a new bulb cos it's so old.

Will let you know how it goes.

THanks again

Mike

Hi Jim,

Looking at http://www.toyodiy.com/parts/p_E_2002_LEXU...EAGKW_8101.html it seems that in addition to the bulb there is thing called a "light control computer" (this ties up with the manual). I presume this includes all the gubbins - ie. ballast, relays etc - as it costs over 500 euros.

I think what I'll do first of all is switch the bulbs around to see if the problem moves over. If it does then it must be the bulb and I can just change it. If the problem remains on spite of switching then it is probably the light control computer.

Hopefully it's the bulb - it has done 186,000 miles and I always drive with the lights on so it may well just be the bulb.

Will post how I get on.

Thanks again.

Mike

Thanks Jim,

I have heard of "Ballast" but can see no mention of it in the manual. Where is it located?

Thanks

Mike

Hi,

I've just noticed that one of my xenon headlamp bulbs goes off after about 2 minutes driving.

If I switch the headlights off and on again it lights up again but goes off again after 2 minutes, and so on.

Any idea what's happening and how to fix it?

Thanks.

Mike