Hi Everyone,
So here's a long story short. I have a mk2 Punto 1.2 16v sporting.

The exhaust looks like it is causing the airbox to melt. I changed the bottom half of the airbox that contains the filter thinking it was caused by a recent overheating issue I had but its now melting the new airbox.

Connected to the ECU and it reads P0340 camshaft position sensor error code, cleared it but it comes back when the engine is started. I changed the camshaft sensor for a new one and still has the fault. There doesn't seem to be faulty wiring with that sensor.
Also has a P1135 pre cat sensor error.

Does anyone know what is causing the airbox to melt and how to rectify the camshaft position sensor error?

Much appreciated!

codes are a guide not the law
although you give some information you dont give all so im going to go for blocked cat causing excessive underbonnet temperature and error codes

oh and welcome

Has it recently had a timing belt done? OR work related to timing, such as water pump or a tensioner?

As there tend to be 1 of 3 things i've seen beent he cause

1 - the timing is out, and the car is telling you that
2 - the Wiring is damaged, since you've overheated, could be the wiring has too!
3 - the sensor at fault

since you've done 3 already, i'd be inclined to just check the wiring from sensor to ecu

Unless you've had timing work done, then that needs checking first with the proper tools! No tipex here im affraid

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P1135 = "Oxygen sensor heater resistance Bank 1 (Pre-cat)".

2 tests i'd be doing

Pin 3 and 4 - Autodata states resistance between 4 and 11 Ohms - sensors disconnected - this will tell you if the heater coil is going over resistive, or open circuit
Pin 4 and Earth - Check at Car wiring loom to the sensor (NOT THE SENSORS WIRING) - Disconnected - Should see 11v - 14v With ignition on, however i'd wanna see battery voltage or very near battery voltage

Ziggy

Ziggy

I had a melted air box on mine.

Its easy to fix.
Just find a exhaust heat shield to cut up or use a oven roasting tray..
Cut a square off it ..shape it to cover the lower part of the air box and fasten it on with some
10mm nuts and bolts..
Mines been fine since.. saves buying another air box that I'd guess would just melt again anyhow.

Re the timing issue'
The phase sensor. Sees tdc on initial start up..so if timing is out
It will keep doing it.

Timing on these can be out 3 ways.. it couid be out on the inlet cam.
Get hold of a set of timing tools and see if both camshafts will lock off..

Do you understand what I mean..
If not just give us a shout and I will explain further..

Ziggy122 said:

Has it recently had a timing belt done? OR work related to timing, such as water pump or a tensioner?

As there tend to be 1 of 3 things i've seen beent he cause

1 - the timing is out, and the car is telling you that
2 - the Wiring is damaged, since you've overheated, could be the wiring has too!
3 - the sensor at fault

since you've done 3 already, i'd be inclined to just check the wiring from sensor to ecu

Unless you've had timing work done, then that needs checking first with the proper tools! No tipex here im affraid

-------------

P1135 = "Oxygen sensor heater resistance Bank 1 (Pre-cat)".

2 tests i'd be doing

Pin 3 and 4 - Autodata states resistance between 4 and 11 Ohms - sensors disconnected - this will tell you if the heater coil is going over resistive, or open circuit
Pin 4 and Earth - Check at Car wiring loom to the sensor (NOT THE SENSORS WIRING) - Disconnected - Should see 11v - 14v With ignition on, however i'd wanna see battery voltage or very near battery voltage

Ziggy

Ziggy

Click to expand...

Thanks Ziggy. I've checked the Lambda sensor and wiring.
Pins 3 and 4 = 10.5Ohms
Sensor disconnected then probed Pin 4 to Earth on ECU wiring side with ignition on = 13V which was pretty much battery voltage.

The timing belt looks pretty tight so I don't think it's slipping but I could be wrong. I'm stumped. I've called a local garage and booked it in for Monday.

I will take the CAT of tomorrow and have a look. Is it easy to tell if it is blocked?

Just becUse the belt is still tensioned doesnt mean the timing is out if any work on it was done which u havent answered


Ziggy

No body listens on here Ziggy..

Ziggy122 said:

Just becUse the belt is still tensioned doesnt mean the timing is out if any work on it was done which u havent answered


Ziggy

Click to expand...

No work was done on the timing recently. I've had the car for about 6 months or so.

Oh and Oldhammer, people don't listen.

Did the car come with Engine management light on when you first bought it.

oldhammer said:

Did the car come with Engine management light on when you first bought it.

Click to expand...

No it didn't.
These faults should have triggered the light.
Sooo using the FiatECUscan I did an instrument panel test and the engine management light did not come on.

Seems a bit suspicious. Do these fail? Can the lights be "turned off" by someone trying to hide the fault?
I'm going to take the panel off and have a look.

Hi,

The lights on the dash are actually SMD (led) and cannot easily be removed, and I've never personally known one "go" of its own accord. A common trick though is to put some black tape over the SMD on the board.

The dash does a self test on startup, and if a SMD was faulty, it would say "LED fail" in the display where your mileage is.

To me, it says that whoever sold you this car couldn't solve the problem your having and simply taped over the SMD for the EML. Tut tut.

Alan

Bumblebee1 said:

No it didn't.
These faults should have triggered the light.
Sooo using the FiatECUscan I did an instrument panel test and the engine management light did not come on.

Seems a bit suspicious. Do these fail? Can the lights be "turned off" by someone trying to hide the fault?
I'm going to take the panel off and have a look.

Click to expand...

Right OK..

What you need to do is ..check the timing..
My guess is its out..
You can use ..small socket extension bars to use as locking tools
One wouid have to be cut down tho to be able to lock off the inlet cam.

If your in Manchester I've got a set of locking tool's.

oldhammer said:

Right OK..

What you need to do is ..check the timing..
My guess is its out..
You can use ..small socket extension bars to use as locking tools
One wouid have to be cut down tho to be able to lock off the inlet cam.

If your in Manchester I've got a set of locking tool's.

Click to expand...

Thanks. I used to live in Manchester but that doesn't help!
I don't have the time yet check the timing as I am away for a few days.

a1ant said:

Hi,

The lights on the dash are actually SMD (led) and cannot easily be removed, and I've never personally known one "go" of its own accord. A common trick though is to put some black tape over the SMD on the board.

The dash does a self test on startup, and if a SMD was faulty, it would say "LED fail" in the display where your mileage is.

To me, it says that whoever sold you this car couldn't solve the problem your having and simply taped over the SMD for the EML. Tut tut.

Alan

Click to expand...

The weapon of choice for concealment was black permanent marker.
Used nail varnish and a flathead screw driver to get it off.
Disappointing...

It gets better. Now I can hear a high pitch ringing noise when above 35-40mph.
First Fiat and probably the last. Anybody want to buy it?

Bumblebee1 said:

It gets better. Now I can hear a high pitch ringing noise when above 35-40mph.
First Fiat and probably the last. Anybody want to buy it?

Click to expand...

hi
buy a vw polo
they give no problems at all
then again neighbour put heres in for repair yesterday for mot
£600 for mot, new rim and new cat apparently
cars eh

(Now I can hear a high pitch ringing noise when above 35-40mph.)

from what area of car?


why get rid?
just have it sorted.. it will work out cheaper than buying another car.

my punto was a p.i.t.a to start with but now everythings sorted on it its prooved to be a very reliable car,

faults with cars are nowadays fault of the last owner scrimping and scraping
not the fault of the car,

good and bad in all makes.

OK been away for a few days and I'm back now. The high pitch ringing sounded like from the front of the car / engine bay area. I don't hear it all the time. Another thing I noticed was that the oil level was practically empty, strange since it had an oil change a not too long ago. I looked underneath the car and there's a slow oil leak that's leaking on top of the gearbox which is why I didn't notice it on the floor after it being parked. I topped it up with but the ringing continued. I haven't heard it for a couple days now.
I still have the camshaft position sensor error and pre cat lambda error so still need to check the timing.