FTO Drivers Club, Western Australia

Matyp · Guest

when booting the car a i get a rely loud hissing and serius power loss,
any ideas?

RichardH · Joined: 27 Jan 2003 Posts: 804

Get your head into the engine bay and check all hoses, induction system, etc.

If it makes any kind of a noise when revving it in neutral (ie. no load), you can turn the throttle from the engine side and see if you can pin down where it comes from.

Or, ask a mechanic to get in there and listen as you do it. Someone with a good ear and experience might be able to track it down fast.

Has any work been done in the engine bay lately? Maybe something was knocked "almost" out of place in the area of work, and then disconnected completely under normal driving.

- Rich

Matyp · Guest

no work done on it lately,
Just started doing it and the car is half as fast now.
It is realy realy loud hiss, sounds like air being fored at grate presher threw small space.

appart from the hissing and loos of power there are no other affects on the car

RichardH · Joined: 27 Jan 2003 Posts: 804

Gasket leak? Is it smooth, or a pulsed sound?

Seems to me like it should be going to a garage asap!!

- Rich

Matyp · Guest

Its running smooth, the hiss only happens @ wide open throtl it seems
keeps hissing untill gass is let off. the cars 3 times slower than before it started hissing

RichardH · Joined: 27 Jan 2003 Posts: 804

I wonder if the MAP sensor hose has come off, or something.

Have a look at the back of the engine, at the top. On the rear firewall is a small black box, about the size of 2 matchboxes. There is an electrical plug, and a short black hose. The hose should connect the unit (which is the Manifold Absolute Pressure sensor) to the intake manifold.

If that's come off, not only will it suck in lots of air (and be noisy), but the engine ECU won't be able to calculate its fuel delivery when running open loop (ie. full throttle). It will go into a limp-home mode and use other sensors to fill in the blanks... and be crap to drive!

Does the engine warning lamp illuminate at all? It's in the top left of the dash display. It should turn on for about 5 seconds when you start the car, and then stay off from that point on. A MAP sensor failure would be reported by an ECU error code, and the lamp would light.

Take a look, anyway...

- Rich

matyp · Guest

that hose seems ok, there is no engine waning light.

it sounds like its coming from the middle/back of the car on passanger side but cant be shure as it only happens when moving, not when reving in nutral

RichardH · Joined: 27 Jan 2003 Posts: 804

That's where your throttle body is. Along with vacuum hose, crank case ventilation hose. Get the area checked out, as something certainly sounds like it's come loose and is sucking directly from atmo instead of through the filter.

If you've got an aftermarket pod filter, intake pipe or anything, check it it soundly connected.

- Rich

marke · Posted: Thu Feb 10, 2005 5:21 pm Post subject:

I think the advice here is that if you can't seem to find the problem yourself take it to a mechanic who will be able to sort it out for you Smile

The kind of noise you are hearing will definately be related to a cracked hose or hose not connected properly. The fact that the car is noticably down on power will mean the hose is most likely one that is connecting to a sensor.

If you have had a look and can't find anything, drop into your local mechanic and im sure they will be able to find it within a few minutes.

matyp · Guest

If anyoone is intrested, it was a colapsed cat, it was blocking the exust up coussing it to hiss very loud when the gas was trying to flow threw

Guest · Posted: Thu Feb 10, 2005 9:11 pm Post subject:

RichardH · Joined: 27 Jan 2003 Posts: 804

marke · Posted: Fri Feb 11, 2005 6:34 am Post subject:

I should have spotted this one given I had a cracked flex joint from the downpipes a number of years ago!

doh

Guest · Posted: Sun Feb 20, 2005 10:05 am Post subject:

[Rich wrote]

Does the engine warning lamp illuminate at all? It's in the top left of the dash display. It should turn on for about 5 seconds when you start the car, and then stay off from that point on. A MAP sensor failure would be reported by an ECU error code, and the lamp would light.

How do we fix the problem and what's the damage?

RichardH · Joined: 27 Jan 2003 Posts: 804

Not sure I understand the question.

Have a read of this, in case you haven't found it already...

https://ftowa.allanson.org/html/workshop/workshopart07.html

- Rich