V8 Owners - help me diagnose this sound

[markuskj]

In the drivers seat (UK) I can sometimes hear the sound of what I can only describe as a pump behind my head, to the right. Very subtle but also very obvious, and not always present.

A really far out question I know but any thoughts welcome!

[toyroom]

Is it an instantaneous sound like a knock or a clunk or is it continuous like a buzz or a whirr? Clunk will be the chassis bolt sleeves loose in the (shrunken with age) wooden bulkhead. Whirring may be PAS pump. Is it LHD?

Or alternative solution: Turn up the stereo volume !!

[markuskj]

lol - loved th last suggestion!

No, RHD car, it is a whizz sound, relatively high pitched. It is possible to forget about it but as it is random I wanted to ensure it was not a component being stressed.

[JK1]

Could be the fuel pump as that would be on the right side just behind your head although I don't think it's usually that loud. Mabye it's on it's way out....hope not.

[lotusse89]

There's a coolant circulation pump there.

Is there also a vacuum pump which runs sometimes to add vacuum to the reservoir for the ABS system?

[snuffy]

You can hear the fuel pump on start up and it makes a clicking sound. Once you have started the engine you should not be able to hear it. The clicks get futher apart until the correct fuel pressure is reached.

You can get a whurring sound from the brake accumulator when driving. I often used to get this. When low pressure is detected the pump will repressurise the system. This noise comes from the front of the car but it' soften har to tell just where a noise is coming from.

HTH

Adrian

S3->Turbo->GT3->Sport 350.... Noble M12-GTO3
www.adrianmugridge.co.uk

[968ant]

I've had a sound that sounds like yours coming from that area last week!! and it turned out to be an air lock in the coolant system!! sounded like a belt was slipping, we (me and me knowledgable uncle) undid the bleed screw at the back of the engine while the engine was off, let the excess air out and woohoo!! all is well again.

hope this helps.

Ant.

[markuskj]

968ant said:

I've had a sound that sounds like yours coming from that area last week!! and it turned out to be an air lock in the coolant system!! sounded like a belt was slipping, we (me and me knowledgable uncle) undid the bleed screw at the back of the engine while the engine was off, let the excess air out and woohoo!! all is well again.

hope this helps.

Ant.

Would that account for the engine taking a while to heat up? This is something I am suffering currently.

Where is the bleed screw?

[968ant]

I'm not sure about the warming up? I think it would depend on how big the air lock is? but like I say I'm not sure about that one, How long does it take to warm up?

Also, the bleed screw is at the back of the engine, if you send me your email address i can send you a diagram.

Kind regards,

Ant.

[e-mail]

[markuskj]

968ant said:

I'm not sure about the warming up? I think it would depend on how big the air lock is? but like I say I'm not sure about that one, How long does it take to warm up?

Also, the bleed screw is at the back of the engine, if you send me your email address i can send you a diagram.

Kind regards,

Ant.

[e-mail]

Cheers Anthony - email address is [e-mail]

The car takes about 20 minutes driving to warm up.

M

[toyroom]

Hang about, is it a V8 or 4 pot ? The bleed screw for the V8 is at the front of the engine.

[toyroom]

Stupid me, it's in the title! In the V8, the bleed screw is a black hex screw in the top of the water manifold at the front of the engine. The idea is to unscrew this with the engine cold and then pour coolant into the reservoir bottle at the back right of the engine bay until it spills from the bleed screw. You then tighten the bleed screw and fill the reservoir bottle to full. Start the engine and go for a drive. The coolant will find its own level by discharging any excess into the bottle in the rear right wheel arch and the level should then stay put forever.