Constant High Pitched Noise From Engine...

[Jarty]

Hi there,

I have a high pitched noise coming from my car...all the time (no joke).

I have a 1998 Avensis GS which I've owned for a year without any problems. Today I had some tyres replaced on the car, and had the tracking done at the same time.

Then this evening as I got into the car to leave work, I noticed a high pitched noise. It was only when I got home I realised the noise was coming from my car. The noise didn't go away on turning the engine off and locking the car.

The noise is an electric high pitched noise, sounding as if it it being produced by a buzzer of some sort. I'm guessing that the likely culprits are the horn or the alarm. I'm discounting indicator and warning alarms, as this noise is not audiable in the car's cabin.

After trying to contact my local dealer (too late, all mechanics had gone!), and consulting both the car manual, and this site, I noticed the noise had stopped. About to put it down to 'one of those things', and half an hour later it starts again! Great! Weird and intermittant! Just what I need.

I have resorted to disconnecting the Battery to stop it, and look forward to visiting the dealer on Monday. In the mean time does anyone have any idea what is causing (or even producing) this noise? I know that there is no such thing as a coincidence, and so I'm guessing the the tyre change and tracking may have something to do with it. Any ideas?

Jarty

[Desmond22]

I once had a Honda where the electric fan would come on and off after the car was stopped. Is that any help? :)

[Jarty]

I once had a Honda where the electric fan would come on and off after the car was stopped. Is that any help? :)

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It certainly doesn't sound like the fan, it's more of an electronic tone, like when you get a key stuck down on a computer keyboard.

[Jarty]

Hmmmmm, things just got a little stranger.

I disconnected the Battery on Friday to stop the noise, and reconnected it this afternoon (Sunday) to see if the problem reoccured.

Reconnected the Battery, and no problem, no noise.

Several hours later, the alarm goes off. Now it has been a hot day, and on reconnecting the Battery I did open the electric windows slightly to allow some air to flow through. So put it down to a receipt on the seat being blown around by breeze.

However, the strange thing was, that using the key fob to unlock the car didn't disable the alarm. I kept remotely locking and unlockin the car and alarm just kept going. I kept going for its 28 seconds and then stopped of its own accord, only to start again a few minutes later.

Disconected the battery again, and wondering what surprises are in store when I reconnect it tomorrow.

Why will the remote key fob not disable the alarm? Does it have something to do with me disconnecting the battery? Did having my tracking done make the alarm malfunction? Am I going to get the stock response of 'your alarm needs replacing' from the dealer, only to find that the problems still persist? If I need to replace the alarm then how much will that cost?

Any ideas? Jarty :(

[Mkuk0]

Not sure if this is any help, but when I had the Battery dissed on my wife's old Vectra, on reconnecting I had to plip the remote a few times straight away to 'reset' the alarm. It was some security feature to stop thieves just dissing the Battery and towing the car away, as soon as Battery was reconnected, if you didn't have the plip, the alarm went off.

Check the handbook is my advice, if I get a min, I'll check mine and post back.

[Jarty]

Not sure if this is any help, but when I had the battery dissed on my wife's old Vectra, on reconnecting I had to plip the remote a few times straight away to 'reset' the alarm.

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Hi Mkuk0,

Thanks for your reply.

It was one of the things that I was considering when the alarm went off; as I understand it, the alarm will trigger if there is a fluctuation in current (i.e. someone trying to disconnect the alarm). A certainly checked the manual as well to make sure there was nothing I was doing incorrectly with regards to the Battery or disabling the alarm (an RTFM solution would have been embarrassing indeed!).

I reconnected the Battery this morning with no problems, drove to work and left it in the car park unlocked (alarm disarmed). On returning to the car this evening, the siren was sounding, even though the alarm wasn't set (no flashing indicators, and unable to silence with key fob). Drive home had no problems, but as soon as I turned the engine off the siren came back on. Had an ear splitting minute while I disconnected the Battery.

I spoke to my dealer this morning and they suggested that the siren unit had developed a fault. Apparently the siren unit is separate to the sensor/immobeliser/locking mechanism - hence the lights not flashing, and the siren going off even though the alarm isn't armed.

It's checked in for the dealer to have a look at tomorrow. Imminent large garage bill on the horizon I fear...

Jarty

[ndsblack]

Not sure if this is any help, but when I had the battery dissed on my wife's old Vectra, on reconnecting I had to plip the remote a few times straight away to 'reset' the alarm.

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Hi Mkuk0,

Thanks for your reply.

It was one of the things that I was considering when the alarm went off; as I understand it, the alarm will trigger if there is a fluctuation in current (i.e. someone trying to disconnect the alarm). A certainly checked the manual as well to make sure there was nothing I was doing incorrectly with regards to the Battery or disabling the alarm (an RTFM solution would have been embarrassing indeed!).

I reconnected the Battery this morning with no problems, drove to work and left it in the car park unlocked (alarm disarmed). On returning to the car this evening, the siren was sounding, even though the alarm wasn't set (no flashing indicators, and unable to silence with key fob). Drive home had no problems, but as soon as I turned the engine off the siren came back on. Had an ear splitting minute while I disconnected the Battery.

I spoke to my dealer this morning and they suggested that the siren unit had developed a fault. Apparently the siren unit is separate to the sensor/immobeliser/locking mechanism - hence the lights not flashing, and the siren going off even though the alarm isn't armed.

It's checked in for the dealer to have a look at tomorrow. Imminent large garage bill on the horizon I fear...

Jarty

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Two other possibilities!!

1.The internal battery is unserviceable(my mates BMW went same way)We took siren apart and replaced rechargeable batteries and resoldered connections.

2. The wiring to the siren(to recharge the internalbattery) has bad connections or chaffed.

Check multiblock and wiring routing.

These are wild, but educated possibilities and I hope they help.

Even if it means a process of elimination.(don't think thats spelt right!)

Cheers,

Nick.........

[Jarty]

Two other possibilities!!

1.The internal battery is unserviceable(my mates BMW went same way)We took siren apart and replaced rechargeable batteries and resoldered connections.

2. The wiring to the siren(to recharge the internalbattery) has bad connections or chaffed.

Check multiblock and wiring routing.

These are wild, but educated possibilities and I hope they help.

Even if it means a process of elimination.(don't think thats spelt right!)

  Cheers,

  Nick.........

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Hi Nick,

Thanks for the reply. There's a good chance that the internal Battery has gone in the siren, as the siren doesn't persist when you disconnect the main car Battery (it just goes dead!). Your guess of bad connections to the siren may also be on the money, as all this started after having tyres and tracking done - possible vibrations/shocks in the wheel arch area causing bad connections to loosen perhaps.

Unfortunatley I don't have the time to remove the siren unit myself and try to debug the problem. I'm hoping the dealer's mechanics will check the obvious before suggesting that the siren unit needs replacing.

It's at the dealer right now (!) and I'm waiting to see what they say.

Cheers,

Jarty

[Mkuk0]

Sadly I think you Jest sir, chances are Dealer will suggest replacing rather than check for bad connections within unit, they're lazy sods nowadays!

[buzlby]

Hi There

Might be a bit late for this but I'd remove each of the cars fuses individually to track down the circuit. Then its a case of elimination as to the faulty bit

Takes time, but gives you a chance to clean connections at the same time

What did the dealer say ?

Cheers

[Jarty]

What did the dealer say ?

Hi buzlby,

They didn't inspire a huge amount of confidence. Firstly they got back to me and said that they had decreased the sensitivity of the alarm system, and that should sort out my problem.

I pointed out that in fact the siren was going off even when the alarm was disarmed, so decreasing sensitivity probably wouldn't cure the problem. They said they would get back to me, and then about half an hour later phoned to say that the siren unit needed replacing.

As Mkuk0 pointed out, they don't seem to have debugged the problem, they've probably plugged in their diagnositc computer, seen that it reports that everything is OK and then taken a guess that the siren unit was faulty (but obviously having no clue as to what the fault actually is).

Admittedly, the dealers guess is probably based on quite a lot of experience of alarm faults, so I'm willing to accpt their assessment.

As mentioned before, I don't have the time to remove the unit and debug it myself. I'm being quoted £116 to have it replaced (VAT and labour included), which is probably cheaper than the hours of labour needed to strip down the unit and find the fault.

It's booked in for tomorrow to be done; I think I'll ask them to retain the faulty part so I can have a look myself at a later date.

Here's hoping that it cures the problem.

Jarty