Hi,
My car has lost silly amounts of performance and the MPG has gone high,
it also has a stupidly loud squealing from the engine bay (i think)

I have changed lots to fix the squeal but it persists

Cambelt
Tensioner Bearing
Checked alternator by disconecting it
Waterpump
Drivebelt
Lambda Sensor
Oil
Injector Cleaner

as from my other posts regarding this issue i was wondering could it be the catalytic converter.

The car will squeal when in neutral so it cant be the clutch, however i have recently had my front downpipe changed which could have upset the cat hence the losss of stupid amounts of performance + Squeal.

I would prefer to fix the fault my self but just cant diagnose it i will be disconnecting the cat tomorrow to see if she still squeals in neutral without it.

Please if anybody knows if a cat can scream and make u lose performance shed some light on this most annoying problem.

Kind Regards
phil

if you did not use a fiat part for the exhaust you may lose some power it's always best to buy original before the cat

the squealing will be your clutch release bearing they can make a noise in neutral does it alter as you push and release the clutch

I dont believe the noise does alter, when the clutch is dipped the noise will persist, i can control the pitch by the amount of revs i have one it.

could possibly be an air leak on the inlet i assume you have checked al the exhaust components for leaks as that was your main theory

the cat won't cause the sqealing..period...and the downpipe is probs fine. A colapsed cat will kill performance but this seems unlikly.

Is this an OBD car (ie two lambda or one??)

Does it squeal when moving AND stationary? ie. is is speed or rev related?

Can you record the sound so we have a better idea?



Kristian

its got one lambda and the noise will sound when the car is stationary however it is much louder when the car is moving the car will only squeal when reved. eg. i could roll down a hill at 50 without my foot on the accelerator and the noise owuldnt be there but as soon as i touch the peddle it will squea same with if the clutch is dipped.

Thanks

philmoore said:

its got one lambda and the noise will sound when the car is stationary however it is much louder when the car is moving the car will only squeal when reved. eg. i could roll down a hill at 50 without my foot on the accelerator and the noise owuldnt be there but as soon as i touch the peddle it will squea same with if the clutch is dipped.

Thanks

Click to expand...

evaporative loss control valves can become stuck open and cause this to happen does it sound like its coming from the front right hand side of the car

yea the sound is front right, how is this fixed and how hard / expensive is it to fix.

Thanks

well it depends if it's faulty or not as i said it's most likely an air leak

it could be a massive air leak through the brake servo these make a cracking good sound when they go

have you had loss of braking power at low rpm

basically you need to disconnect the blue evaporative loss hose from the manifold and block the hole were it attaches with your finger

then have someone start the car and rev it to see if it goes away

then try disconnecting the brake servo hose and blocking the hole into the manifold

after these 2 there is not a right lot that could lose so much power and gain a noise

if you take of the servo pipe without blocking the hole the engine will not run at all due to the massive air leak just to give you an idea of what these things are capable of

if you need to know what and were these 2 items are just post back on here and I may counger up some photos

Just unplug the charcoal cannister solenoid to check. It will trigger an EM light, but it should turn off after, and will run fine However you may need to get your code cleared so don't count me on it.

Not sure where it is on the Punto's, I think its on the drivers side, in the engine bay. Look for a pipe that possibly come out of the wing, into a device witha connector, and then a pipe out the other end.

Cheers,

Kristian

/edit - took a while writing that post didn't mean to duplicate stuff

kritip said:

Just unplug the charcoal cannister solenoid to check. It will trigger an EM light, but it should turn off after, and will run fine However you may need to get your code cleared so don't count me on it.

Not sure where it is on the Punto's, I think its on the drivers side, in the engine bay. Look for a pipe that possibly come out of the wing, into a device witha connector, and then a pipe out the other end.

Cheers,

Kristian

/edit - took a while writing that post didn't mean to duplicate stuff

Click to expand...

don't do this

if the valve is faulty in such a way that it is leaking air and stuck open un plugging it will make no difference besides bringing on the em light

this procedure would only be useful when diagnosing an electrical reason why it was permanently open if it was electrically opened and not faulty itself it would not make a noise

it is located at the front of the car unless you have a turbo or sporting 1.6 whereas it is inside the right wing it may also be in the wing on models with power steering as to me it looks like it may be were the pump want's to go

we are trying to find a posible air leak so it's more useful to disconnect various vacuum controlled or fed items to see if the noise stops

If you could get some images of where these hoses are that would be much appreciated, i know where the blue one is as for the others i will have to root around will it say in the manual.

Thanks

here is were the vacume pipe enters the brake servo
the round thing that looks like a saucer with a pipe hanging down out of it
this can be simply pulled out of here then blocked with your finger wile someone starts the car that will tell you if the servo is faulty if the noise stops



the pipe here with the yellow clip on is were the servo pipe enters the inlet manifold



here is the charcoal canister



the ruber pipe with the yellow clip onto the canister is the vent from fuel tank

the small blue pipe is from the canister to the valve then from there to the inlet manifold
and of course the wiring to the valve

this valve is normally activated at high speeds or high engine rpm's with low throttle angles to purge the canister of fuel vapour if this valve becomes damaged it can result in a permanent air leak after the throttle causing posible lack of power and the noise you here

but the same can be said for the servo these have a large diaphragm in them that when split can also make a noise as air rushes through it into the manifold

if you squash the rubber pipe in between the canister valve and the blue pipe to inlet this will isolate this part

Well i know that i dont have any lack of braking so would that point towards the charcole canister which end of them do i disconnect the blue one going into the canister ? i got confused lol.

Thanks for taking the time to take the pics.

philmoore said:

Well i know that i dont have any lack of braking so would that point towards the charcole canister which end of them do i disconnect the blue one going into the canister ? i got confused lol.

Thanks for taking the time to take the pics.

Click to expand...

just squash or kink the rubber piece between the electro valve and the blue pipe going to the manifold this will stop any air flow through it

if he noise stops then that's your answer

the best way to absolutely check the brake servo is to run the engine for a few seconds then turn off come back an hour later and press the brake a few times it should go from soft to hard after one or 2 presses my car holds it's brake servo vacuum for days on end

if not then you'll have to look else were for the noise but it definitely sounds air leak related

did the lack of power and the noise start at relatively the same time

there is one more pipe you could check that would alter power but no necessarily make a noise

its coming from the same union as the brake servo pipe does and it goes up under the plastic cover on the bulkhead to the map sensor

Yea i think power loss then noise but was within a day or two of each other
so squash the pipe that goes to the inlet manifold, if it is this how do i fix it

Is this the rubber piece

yea that one

if it does stop making the noise when you do this simply replace the valve there not expensive from fiat and you just need a few simple tools to do it

it's best not to try and bypass this system as you will end up with a canister full of highly flammable gas in the engine bay and no means to purge it

you could always pop to a local scrappy and get one there is a punto in ken allens morcambe

Is the valve the black thing that the pipe goes into or do i replace the whole canister, thanks very much for your help .

yea the valve is the separate piece on top

So if i press that tube and the noise persists do i will check the other pipes, will the squeal be made by the valve or could air leak as it goes into the inlet manifold.

If the valve was faulty would that make my fuel consumption go up because the cat coulnt work properly ?

Also the valve is what is leaking air? therefore loss of performance?

THanks again been a bit help