Hi all, car has been running abit lumpy lately, got it scanned and is showing that the O2 sensor is faulty causing this, the timing chain seems to be rattling loud also, do these need replacing or can they be tightened? 

1.4 MPI? No, they can't be tightened and there is no tensioner in the design. They are notorious for rattling as the miles mount up, never heard of one snapping though. Nothing you can do apart from live with it or replace it.

 

Regarding the O2 sensors - there are two of them, one fitted before the catalyst and one after it.

Edited 29 February, 20206 yr by TMB

8 minutes ago, TMB said:

1.4 MPI? No, they can't be tightened and there is no tensioner in the design. They are notorious for rattling as the miles mount up, never heard of one snapping though. Nothing you can do apart from live with it or replace it.

 

Regarding the O2 sensors - there are two of them, one fitted before the catalyst and one after it.

Thanks for that TMB, so would the timing chain rattle cause the o2 sensor problem ? 

Not sure which sensor he said just the sensor is showing a fault code 'P0140'

No the chain won't affect the O2 sensors. They rattle but don't usually cause running problems. The code P0140 means it's the 02 sensor after the catalyst. Could be the sensor or its wiring.

37 minutes ago, TMB said:

No the chain won't affect the O2 sensors. They rattle but don't usually cause running problems. The code P0140 means it's the 02 sensor after the catalyst. Could be the sensor or its wiring.

Cheers mate, are the 2 sensors the same ? Just in different positions 

Also is they any common faults with the coolant level dropping every other day, I need to top the fluid up once every 2/3 days as the red temprature light starts flashing, dosnt over head or no creamy stuff in oil ..? 

1 hour ago, LordRodders said:

Also is they any common faults with the coolant level dropping every other day, I need to top the fluid up once every 2/3 days as the red temprature light starts flashing, dosnt over head or no creamy stuff in oil ..? 

 

Textbook head gasket failure. Bad luck.

2 hours ago, LordRodders said:

Also is they any common faults with the coolant level dropping every other day, I need to top the fluid up once every 2/3 days as the red temprature light starts flashing, dosnt over head or no creamy stuff in oil ..? 

 

Check for leakage at the radiator thermoswitch (just above bottom hose connection to radiator). It seems to be a very common fault, and is fixed by simply tightening up the thermoswitch a bit.

8 hours ago, LordRodders said:

Cheers mate, are the 2 sensors the same ? Just in different positions 

 

They are different.

 

Not sure what year your car is but my O2 sensors (2003) are...

 

Pre-catalyst 1K0 998 262 G

 

Post-catalyst 06A 906 262 AJ

13 hours ago, sepulchrave said:

 

Textbook head gasket failure. Bad luck.

What's text book about it ? Only thing it's doing is losing bits of water, not over heating, no mayo in oil etc 

9 hours ago, TMB said:

 

They are different.

 

Not sure what year your car is but my O2 sensors (2003) are...

 

Pre-catalyst 1K0 998 262 G

 

Post-catalyst 06A 906 262 AJ

Thanks! Mine an 2003 also 

3 hours ago, LordRodders said:

What's text book about it ? Only thing it's doing is losing bits of water, not over heating, no mayo in oil etc 

Thanks! Mine an 2003 also 

 

Sorry if I seem hasty but if the 1.4 MPI has an Achilles heel, it's the head gasket, Skoda released a revised and improved head gasket known as a TEMAC gasket to address this problem.

Head gasket failure on the MPI engine generally doesn't do anything except lose water through pressurisation of the cooling system which blows out of the tank cap while being driven.

I'm happy to be wrong in this case but generally MPI losing coolant = HGF.

So you should definitely get it tested rather dithering about looking at every other possible reason first.