Coolant Temperature Sensor replacement on AAZ

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hicksy
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Posts: 223
Joined: 28 Apr 2009, 08:49
80-90 Mem No: 9372
Location: Bexhill on Sea, East Sussex

Coolant Temperature Sensor replacement on AAZ

Post by hicksy »

Hi all,

This is my first techy type question, so Ill make it a quicky!
Using the wonders of 80-90 Wiki, I found the issue with my temperature guage, as ever since I have had my replacement AAZ fitted, the temperature gauge did not read the temperature.

It turns out its a faulty temperature sensor so I bought a replacement. My question(s) are:

1: On fitting the new sensor, should a couple of wraps of PTFE/teflon tape be used on the thread? As its a liquid seal I would say yes but im afraid this will eliminate the grounding suface needed for the sensor to work properly. Please advise.

2: Will I need to re-bleed the system or can I get away with replacing the sensor without allowing too much air in?

Thanks all in advance,

Hicksy
See the resto of Frank, my bug, here: http://www.volkszone.com/VZi/showthread.php?t=666711" onclick="window.open(this.href);return false;

See My Caravelle to Camper self build here: http://forum.club8090.co.uk/viewtopic.php?f=40&t=85063" onclick="window.open(this.href);return false;

hicksy
Registered user
Posts: 223
Joined: 28 Apr 2009, 08:49
80-90 Mem No: 9372
Location: Bexhill on Sea, East Sussex

Re: Coolant Temperature Sensor replacement on AAZ

Post by hicksy »

Evening,

Right, this evenings update with the problem in hand.

I replaced the temperature sensor, without ptfe (as I didnt have any left!) and water dribbled out of the hole. Now in my mind that would have let air in somewhere so I proceeded to remove the spare wheel, and drop the rad a bit to bleed the system.

This worked great as a fair bit of air escaped from the rad so it did its job. Trouble is, the bloody gauge still doesnt read any temp! :shock:

Once again, I removed the sensor lead and put it to earth to check the guage works and it does. Therefore, the only thing I can think of is No43 relay behind the dash. Could it be anything else? Answers on a post card please!

I also noticed as it was getting dark, that my batt light in the dash pod flickers slightly when the engine is on tick over, and, that when I switch my lights on, the green indicator relay lights up briefly.

I think I may have to investigate the earths. Do you concur? And could this tie in with the guage issue? Thanks in advance,

Hicksy
See the resto of Frank, my bug, here: http://www.volkszone.com/VZi/showthread.php?t=666711" onclick="window.open(this.href);return false;

See My Caravelle to Camper self build here: http://forum.club8090.co.uk/viewtopic.php?f=40&t=85063" onclick="window.open(this.href);return false;

hicksy
Registered user
Posts: 223
Joined: 28 Apr 2009, 08:49
80-90 Mem No: 9372
Location: Bexhill on Sea, East Sussex

Re: Coolant Temperature Sensor replacement on AAZ

Post by hicksy »

I have found the fault, and its not the relay, or was it the sensor.

Turns out the coolant hose socket/flange that bolts to the block, where the temperature sensor screws into, is not grounding to the block due to too much sealant in the join, therefore the sensor is not grounding and not completing the circuit.

To repair the fault, without removing the flange, I will run a secondary ground wire from a bolt on the flange, to a bolt on the block.

Thanks all for looking. And if you have a similar issue, I hope this helps
See the resto of Frank, my bug, here: http://www.volkszone.com/VZi/showthread.php?t=666711" onclick="window.open(this.href);return false;

See My Caravelle to Camper self build here: http://forum.club8090.co.uk/viewtopic.php?f=40&t=85063" onclick="window.open(this.href);return false;

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