"hunting" Sound From Engine When Cold Or Hot!

[madon37s]

Hi, My wife has a Yaris D-4D 1.4 T-spirit on a 53 plate.

My question is does anyone know what this "hunting" sound can be? She has had the glow plugs replaced (came up on a diagnostic) which certainly makes the car start more easily and it does seem on the whole a lot more smoother but it still has this "hunting" noise which makes it rev like that aslo!

It still gives great mpg and drives well but it is annoying and obviosly shouldn't be doing this. The man at the garage said it could be something to do with the little vaccuum valve that the accelerator is attached to.

Has anyone had this problem or may know what it is?

Many thanks in advance for all your help.

Paul

[Madasafish]

I suggest you start by cleaning the EGR valve and the associated inlet manifold. It's very likely to be heavily carbonned up. Cheap and easy to do.

If that fails...then it gets more difficult.

[madon37s]

Hi and thanks for quick reply,

Can you tell me where the EGR valve might be on the engine and what it looks like?

[Madasafish]

Open Bonnet.

Look at engine

On RHS, you will see a rusty cylinder about 10cms long x 3cms wide mounted vertically on engine . Attached with two bolts.

[madon37s]

Thanks, will have a look at that first.

[Cyker]

I feel we should sticky this thread

http://www.toyotaownersclub.com/forums/topic/106561-cleaning-your-egr-valve/

[madon37s]

Hi all,

Thanks for all your help, I have taken the egr valve and the throttle boby off and cleaned them both up (there was a hole inside the throttle body that was totally bunged up).

The car now runs sweetly with no hint of hunting whatsoever.

Cheers again everyone.

Regards

[Madasafish]

Glad you are sorted