How many coolant sensors?????

[aki508]

Hi guys i have a seat ibiza tdi sport 130pd. Recently the coolant light flashes and beeps at me, Ive changed the one on the gearbox end but the fault still happens. Am i missing another one somewhere?

There isnt one on the coolant bottle so im totally stumped as to whats going on. Any help would be appreciated.

Oh and the coolant level is fine!

 

[Viking]

There should be a level sensor in the coolant top up bottle. It's 2 wires sitting in the level where the coolant should be, and they corrode up and give misleading level readings. The ECU thinks the level is low and flashes up the coolant light.

Carefully and gently scrape the wires with a small screwdriver and it should clear the problem.

 

[aki508]

Ive had a look and there are no wires or cables going into the top up bottle. There are only the two main coolant pipes and thats it.

Totally stumped!!

 

[glynnd]

Take the top off and you will see them.
Easy way round it is to overfil slightly, but only use G12 coolant.
Mine did it especially when cold in the mornings ie frost!
The overfill stopped it straight away.
Glynn

 

[aki508]

mine doesnt have sensors in the bottle. the only things connected to the bottle are the two coolant pipes for the feed and return and thats it.

 

[aki508]

dont suppose anyone can shed any light on my problem? my coolant bottle definatley does not have any sensors on. So where does the dash board get the coolant level from and constantly put the stupid red light on?

Its had a brand new temperature sensor on at the end of the block bear the gear box and its made no diference at all.

Its so so frustrating!

 

[Viking]

What year is your car?

 

[aki508]

Its a 52 seat ibiza tdi sport 130pd

 

[Viking]

Well, ETKA is showing the coolant bottle as having the connector fitted for the level sensor, and the part number for the bottle is the same as other models which do have the sensor fitted.

Can you see a part number on the bottle so I can cross reference it? Maybe someone put a non standard bottle on at some point and linked the wires with a resistor, and now that link is failing for some reason.

Look around the area for a loose plug which would clip onto the bottle and see if that's there. The sensor mount is in the top half of the bottle and enters the bottle at a 45deg angle.

 

[aki508]

ive just dropped my car of at the garage for a service and totally forgot to check the part number.

Its the standard coolant bottle which does have a connector for a plug but i can honestly never recall seeing a plug ever connected to it.

What would help is if anyone who has a seat ibiza 130 tdi sport to check under their bonnet for me!! I dont know anyone who owns one like mine to be fair!

 

[Viking]

It's a standard engine across the VAG range, and they all have the same coolant bottle and sensor system fitted. The plug should be somewhere close by to the connector and might've just fell off.

 

[aki508]

very strange!! Ill have a look as soon as i get the car back from the garage tomorrow. If the plug is off youd expect to have the light and the beeps come on straight away but there is always a delay sometimes straight away and sometimes 10mins after driving?

 

[Viking]

See, there's a fix some people used to do to prevent a known problem some time ago. The coolant bottles used to leak where the sensor is fitted into the bottle, and coolant used to weep out under pressure. The connector being clipped on with a watertight seal meant that the coolant had nowhere to go and used to creep down the wires and into the electrical system, and it went everywhere there was a wire to go down. Google "Coolant migration" if you want to find out more. People used to disconnect the plug and fit a certain resistor across the wires to fool the ecu into thinking the level was okay. With no plug connected there was no change of the electrics being filled with coolant. Maybe this was done at some point and the resistor is now failing.

 

[aki508]

sorry to re-open this again.

Im basically still having the same problem. Now i know for a fact that the coolant bottle does not have or need a connector fitted. The Seat garage has confirmed it and ive also had a look at another car thye exact same spec as mine and it doesnt have one either. Im still getting the 3 warning beeps and the flashing red light. Ive done everything ive thought of and am still totaly stumped.

Are there anymore temp sensors that have a nock on effect to the coolant reading on the dash and give the warning sounds? Its very intermittent, sometimes happens as soon as i turn the engine on and sometimes after a couple of hours of driving. To be quite honest its driving me mad

Any help would be very appreciated.

 

[Toxic]

get someone with VAGCOM to see if there is any error codes flagged up on the car. at least then it may give you an indication of what is the fault. you may also have a coolant sensor above the Oil filter housing have a look at all your water pipes and where they enter the engine block you have have a sensor there.

 

[muddyboots]

I don't have my Ibiza anymore so can't check, but I'm 99% sure mine didn't have a sensor in the coolant bottle either.

I'd suggest you need someone with vag-com to read off the exact faults that are being recorded. Clear the faults first so there's no others to mislead you, then trigger the faults/warning beeps as usual, then go back in with vag-com and read what faults are flagged up.

Could be a dodgy temperature sensor...

 

[aki508]

Ive had it plugged into vag com before and no faults came on even when the beeps started. Ive changed the sensor at the left hand side of the block too but still it beeps!

I know where the dash board gets its temp from but where does it get its coolant level from?

 

[aki508]

Ive had it plugged into vag com before and no faults came on even when the beeps started. Ive changed the sensor at the left hand side of the block too but still it beeps!

I know where the dash board gets its temp from but where does it get its coolant level from?

sorry its not on the left of the block, its the one on the right just above the gearbox.

 

[Muttley]

If there is no level sensor in the tank, then your car doesn't have coolant level sensing. The header tank is the only free surface in the cooling system so you can't put a level sensor anywhere else.

The only coolant sensor you have is the one you have already changed. It has two sensors in the one housing, one (G2) feeding the dashboard and a separate one (G62) feeding the ECU.

Flash+beeps is the dashboard warning of a coolant problem. Not necessarily level, just a problem, a reading out of spec.

If you see no faults with VAG-com, then the ECU must be seeing reliable data. Perhaps VAG-com doesn't test the sensor feeding the dashboard, just the one feeding the ECU?

One thing you might try is cleaning the connector to the sensor unit. Spray with electrical contact cleaner, plug and unplug several times to try to wipe the contact surfaces clean.

Otherwise it might be time for a new sensor assembly - but I'd like to know if VAG-com can detect faults in the G2 sensor, because that's where your faults most likely lie.

 

[aki508]

Brilliant stuff. Thankyou very much for the comprahensive reply. The first thing i think ill do is clear all fault codes and try re-creating the fault.

Ill completely flush my engine through with fresh water and then put new coolant in and clean the sensor and check the plug!

Im sure ive had vag com on before when the dash board has been beeping and no fault codes have come up. Its wierd and very annoying!!

the two sensors, g2 and g62, are they two sensors in the main temp sensor?