Strange noise on start up

bazz26

Hi folks,

I have noticed on the rare occasion that when I start my car there is a strange sound coming from the engine or starter for about 2 seconds and then it goes away again. Doesn't happen all that often, hard to describe but it sounds like someone dropping a bag of spanners on the floor. It can happen from a cold start or not.

As I said it only lasts for about 1 or 2 seconds when you turn the key the odd time. I'm far from being mechanically minded but I was guessing maybe the tappets might need adjusting but then my understanding is that the tappets are self adjusting these days so more than likely I am wrong here. I did mention it to my mechanic at the last service but in typical fashion he could not replicate the noise at the time.

It doesn't interfer with the car or anything and my mechanic says the car is running fine with no issues but at the same time I would like to find out what it is in the event it is a prelude to something more serious or costly down the road.

BTW the car is a 2003 Toyota Avensis 1.8 VVTi petrol with 150k miles.

Thanks in advance.

mike65

Need to figure out where its coming from so you need someone to crank while you listen, it could be the gear teeth on the starter motor are'nt quite in alignment.

Check this article

THE GRINDING NOISE

At the beginning of this article, I spoke of a grinding noise you get sometimes when you try to start the car. Most often, you can just turn the key off and try again. Sometimes it takes several attempts to get the car to crank. Grinding occurs when the gear teeth of the starter motor and the flywheel ring gear fail to engage. The starter motor powers up and the gears grind against each other. Over time, this erodes the matching surfaces (bevels) on both gears, making the engagement process progressively more difficult. While there may be a mechanical reason for the problem, in many cases something is marginal in the electrical system. For instance, it may be that the solenoid is not getting enough power to solidly place the bendix gear in mesh with the ring gear. In that case, cleaning up the circuit supporting the solenoid will help. Another possibility is that there is a problem with the ground strap, making the circuit sluggish. In that case, working with the ground strap as previously described (or replacing it) will help. Certainly, installing the suggested supplemental wiring will have a positive effect, as it increases the available ground path. If the car usually cranks normally, and occasionally grinds, I would troubleshoot this particular problem in the following order (taking care to use the precautions mentioned in the earlier text).

Clean and tighten the clip lead to the solenoid.

Clean and tighten the Main fusible link (1st gens).

Install the supplemental wiring

Replace ground strap.

I actually replaced a starter motor because of the grinding problem, but it did not go away. As I worked through the above items (trying to solve another problem) the grinding became progressively more rare.

I doubt its a current issue though on a 4 year old car.

Mike.

bazz26

Cheers Mike, yes knowing where exactly it is coming from would narrow it down alright. The thing is it happens so rarely that you cannot always be standing there with the bonnet up and having someone listening for it.