Lost Dash Engine Water Temp , Meter = 0 when HOT

[AGB-S3]

Lost Dash Engine Water Temp , Meter = 0 when HOT

Gauge showing taking 'double the time' to warm up
Odd behaviour , started to show temp dropping on M-way
Never indicted more than 90

Now on the way home, M-way gauge dropped to '0'
Heater max temp -normal , no engine lights etc

Assume this is the Temp-sensor , should there be ECU fault code ?

Ideas as to where the sensor is ? is there 'one' that links to the Dash Gauge ??

Tnx-Graham

 

[MPH]

Lost Dash Engine Water Temp , Meter = 0 when HOT

Gauge showing taking 'double the time' to warm up
Odd behaviour , started to show temp dropping on M-way
Never indicted more than 90

Now on the way home, M-way gauge dropped to '0'
Heater max temp -normal , no engine lights etc

Assume this is the Temp-sensor , should there be ECU fault code ?

Ideas as to where the sensor is ? is there 'one' that links to the Dash Gauge ??

Tnx-Graham

Graham had similar issues that turned out to be the thermostat!

Sent from my SM-S908B using Tapatalk

 

[AGB-S3]

I thought that at first, but , the Temp stayed at 90 when working , and now, with the dial showing '0' ie not moving off the left side stop -engine is normal temp

Im seeing there are QTY-2 senders on the engine ?

Also had gray/blue smoke after the engine had been ideling for a long time -clear now , could that be the 'choke' thinking its not warmed up?

 

[MPH]

I thought that at first, but , the Temp stayed at 90 when working , and now, with the dial showing '0' ie not moving off the left side stop -engine is normal temp

Im seeing there are QTY-2 senders on the engine ?

Also had gray/blue smoke after the engine had been ideling for a long time -clear now , could that be the 'choke' thinking its not warmed up?

https://webautocats.com/en-gb/etka/audi/a3/201/919400/ sensor part numbers locations etc

 

[s3mad_dude]

I experienced similar on my 8L last year.

I replaced the temp sensor (green thing in the coolant flange) and it made no difference. My car would get up to 90 after a long time but then start dropping. Turned out to be the thermostat in the end.

I’d replace thermostat and temp sensor if I were you at the same time. Might also be worth renewing the coolant flange on the side of the engine block if it’s not been done before. The seal goes eventually and the part isn’t expensive. Make sure you’ve got some spare jubilees clips on hand before you start that job though.

 

[AGB-S3]

Ok , On the run back from the shops , everything looked normal , for now , The sender is probably the original, The flange was exchanged for Alloy casting last year, with new Stat , Engine temps look ok with the gauge reading 'zero'
New sender to fit at the end of the week- could change the two ..
Tnx-Graham

 

[<tuffty/>]

the temp sensor is a dual sensor setup so one for the ECU and one for the dash... not unusual for one or other to fail and for the ecu to see a different temp to what you see on dash

You can check this in vcds but its a common enough fault and a cheap enough sensor to replace

<tuffty/>

 

[AGB-S3]

Dual - That explains the 4 pins then ? hows it configured, is the probe separate to the collar or something ..?

The socket shroud was black , the new one is green, was probably the original ?

New thermostat and new sender , first tesco run this morning, cold idle [13c] about 1300 rpm and engine up to full temp 5 mins or so running ,

was the thermostat u/s ? hard to say, but, running speed / air con did alter the dash temp, as was going to the shop -changed both with Audi parts,

Tnx-G