NoGaBiker

I searched on here and found someone in Cayenne forum complaining of this, and others piling on with "Yeah, me too," but never found a solution or even a definition of the problem.

Just bought a 2002 X50 with 18k miles. All is well except some of the time (50%?) the following happens: insert key, turn to acc prior to firing. a rapid ticking sound, perhaps 3 per second, begins. Sounds like it's coming from behind the right side of the instrument panel. The Cayenne guys all thought their sound was from the PCM, but I don't have that. But if I did, I would probably be thinking it was coming from PCM also, since it's the right side of the panel.

It lasts about 5-7 seconds, no matter what I do -- ie, if you just let it go, or if you go ahead and fire up the car, it still lasts for that period. Then it just quits. Everything works fine. When shutting off, it does it again after shutting off the engine. Same length of time. Doesn't matter if you pull the key out or leave it in ignition for the 5-7 seconds, the sound persists. Then it quits.

Seller has owned it for 3 years, 3000 miles. Said it was doing it, sporadically, when he bought it in. Took it to dealer (dealer's records confirm when I checked.) Dealer said let us take the dash apart and see if we can figure it out. He said that sounded scary so he said nope. Dealer's service record just says "He didn't leave it here long enough for us to diagnose." Both dealer (in talking to me privately) and seller mentioned new panel as being about $3000.

Soooo, after the long intro, just wondering if this has happened to anyone else on here, and more importantly, if the solution was found. Any help greatly appreciated.

By the way, I'm wild about the car! Whew! Just met up with another board member who has had his 2003 for about a year. This is fun stuff.

Macster

My 03 (which does not have PCM or NAV) makes a similar noise upon occasion. I can't really find a pattern other than it appears to most likely to happen after the car has sat a while unused.

Why I think this I do not know but I sort of think it is something related to the heater/vent controls.

What I think is going on is When the key is turned on the auto climate system (even if the unit is not explicitly in auto climate mode which is brings up another bit of confusion which I will attempt to clear up below) attempts to regain the selected settings.

The clicking is the air control flaps being brought back to their prior positions after having lost them over time as vacuum was lost.

As for auto climate... there is the more obvious auto climate mode when Auto is displayed and the snowflake symbol is lit.

But if one turns off the A/C compressor (presses the A/C button and the snowflake symbol goes dark) the system will still attempt to automatically adjust air flow to keep the cabin at the specified temperature.

Only when one manually changes the air fan speed does the unit then enter manual mode.

NoGaBiker

Interesting. I wonder if stabbing the fan speed button while the noise is happening will have any impact on the noise? Also, does yours do this sometimes on shutdown, or only on startup? Mine is at least as likely to do it on shutdown.

NoGaBiker

Okay, another couple data points:

1) HVAC controls have no effect on the sound if operated while it is happening.

2) On startup, the instant the last tick happens, all guages swing up smartly to their proper position. Before that, they had been lying dormant and flaccid down on their pegs, even though the ignition is all the way over to ACC (or whatever the last position before Ignition is called.)

Any thoughts, guage gurus?

Macster

Well, based on (2) above I'd wonder about the ignition switch or possibly a relay that is weak.

The trouble is the symptoms happen so seldom with my car that I really do not have the presence of mind to try various things like working the A/C controls. I do not recall seeing any odd behavior from the gages or the dash lights either. I can't even remember if the noise occurs before I insert the key in the ignition, or occurs once I turn the key to the on position. I believe I hear it after unlocking the door and getting into the car but I get in and insert the key automatically in one fluid motion that I just do not pay that much attention.

All I know is I've heard that ticking noise. Have I heard it from the Boxster? While it too has auto climate control I really can't recall.

My car is in the shop today and tomorrow and when I go to pick up the car if can remember I'll ask the techs if the symptoms rings any bells.

Tytus

Isn't it the fuel pump priming? I find if I don't let the ticking end it takes a second longer to start when cranking and it starts right away if I let the ticking stop. I never gave it much thought until it was brought up.

Tytus

NoGaBiker

Nope, not the pump. As I said above, the car has been in to the dealer and to Motor Werks Racing and neither had any idea without pulling everything apart. I was hoping someone else had experienced the same thing and already pulled everything apart!

Macster

Well, I asked about this noise and the tech reported having not ever heard it.

We talked and he liked my idea it was coming from the AC system but he also pointed out there are a number of relays under the dash above the fuse box cover on the driver's side of the car.

I like this idea a relay could be at fault now even better.

The problem is the noise appears so seldom and I can't know in advance when it will appear. As I'm sure is the case with you most of the time when I get into my car I have things to do and places to go and I'm thinking about many other things than a very very intermittent noise that doesn't appear to be connected with anything serious is way down on my list.

As a result when the noise appears it catches me unprepared.

I note it and try to pick up any clues as to its source but as long as the noise stops, the engine starts and runs ok and there are no other signs of any issues my interest in the noise drops to near zero pretty darn quick.

If the noise appears more often in your car one suggestion would be to if you can reach it put your hand on the relays under the dash and thus be ready to feel if the noise is coming from that area. I would have to think if a relay were making that noise it ought to vibrate some.

I would not tear anything apart.

NoGaBiker

Not a bad idea. It happens, I'd say, 70% of the time, and goes in waves; if it did it once, it will do it again every time you turn the ignition one way or the other sequentially. Then the next time you get in the car it might not do it, two or three times in a row. But then it's back to doing it.

So, it is easy for me to test it. Also, my car is new so its VERY easy for me to stay focused on it. I'll try to feel around and see if anything is vibrating under there, as far as I can reach anyway. The fact that it is perfectly choreographed with the guage movement probably means something to somebody with any knowledge of instrumentation, but that wouldn't be me.

Thanks

Macster

Admittedly while I"m not a gage/instrument expert I have some understanding of how they work. Based on this this behavior does not appear to be directly a gage/instrument problem. It is a common failure to all the gages/instrutments which suggests something electrical in nature.

The gage behavior and other symptoms appear to due to an electrical problem, possibly involving the relay or fuse to the instrument cluster.

If you want carefully inspect the fuse box and the fuses that protect any instrument related circuits. Check the relay box.

You could go so far as to remove the fuses and relays to check for any signs of corroded contacts.

Look for any signs of moisture. While rare a leaking windshield can allow water in and it will of course go to where it can do harm.

rob0001

I guess one of the servo's / relais the from HVAC system. Try to remove fuse D6 and E7 which are for the AC and HVAC system to rule this out

NoGaBiker

Thank you. Good idea. I'll try it.

SSST

I've had this happen. My Bimmer, wife's MB, and my boat all make odd whirring a clicking noises on startup.

I think it is fairly normal for modern cars. I've never given it a second thought.

NoGaBiker

Okay, I haven't tried fuses yet, but I got a new data point.

This morning, while the ticking was ocurring, I tried pushing up on the underside of the gauge pod that holds the fuel level and temp gauges. When I pushed, the noise changed pitch and when I pushed harder it stopped altogether and the needles sprung up. This was repeatable on every instance. Never did pushing up "cure" the problem for subsequent starts or stops, but it stopped the ticking immediately. :dunno:

Pushing up on the adjacent gauge pods (there are five, this is 4th from the left) doesn't stop the process, but I can get a small change in pitch of the ticking. But as mentioned, the needle sticking feature affects all five of the pods. So it looks to be a completely mechanical problem of some sort, wouldn't it seem?

Macster

How the dash is constructed, etc. I can only imagine from the few times I've seen a car dash out and apart.

Barring the mechanical linkages that are present in the heater/AC system afaik there are no mechanical linkages to the dash. It is all electrical/electronic. (For instance years ago the speedo got its "signal" from a cable that ran from the tranny to the back of the speedo. This cable was driven (spun) by a gear drive at the tranny and was used to generate some electrical signal at the speedo to position the needle. Occasionally these cable drives could get noisy.)

I am ignoring the dash's physical attachment to the car and the instrument pod's physical attachment to the dash. Your description of the noise and my experience with the noise in my car does not suggest to me the noise is a rattle due to a loose mounting bracket.

Thus my take is the problem is only "mechanical" in the sense what you did affected an electrical connection.

You have managed to find a way to affect the behavior -- though not improve it -- so you could revisit the dealer or repair shop and present this to them. However, you are still probably faced with a dash R&R which ain't cheap.

I really wish I could offer a rosier picture but unless the problem is a loose electrical connection (or if I'm wrong and some mechanical linkage problem or even a problem with the dash's attachment to the car or the pod's attachment to the dash) you may be facing the cost of a new dash.