Temp sensor location

[Jim D]

This may seem a like a simple question but I the temp gauge on the dash, what does this monitor. Is it the coolant temp?

The needle on my 1.9 td (afn with jx parts), doesn't move but the light does flash when ignition on. The fuel gauge seems to work fine though.

Could this be the sender or the gauge on the dash. I've been reading up about this as much as possible, but it's all new and quite a lot to take in. I would like to get this fixed ASAP as I'm going on holiday to France soon (where hopefully it'll be hot ) and I would like to know how the engine is doing temp wise.

Thanks

James

[Jim D]

Is this what I'm looking for, does coolant pi$$ everywhere if I take it out unprepared like the fool I am.

[VW T25 Feuerwehr]

The wire circled in blue often comes disconnected which means the needle won't work.



Worth a check before taking anything apart

[Jim D]

thanks for the picture, in my picture above it look as though the connector has snapped off.

i wonder if this is the cause. when i took out the sensor just now, coolant pissed out everywhere which scared me so i plugged it back in (rather haphazardly) do i now need to bleed the system as air would have got in? i'm a little worried now.

i've found it really hard to find out the location of the sensor.

it looks as though there was a red wire attached, which leads me to believe it was the right one.

is the only way to replace this by bleeding the coolant out?

it looks as though there was a bleeder air valve above on the pipe, could this be used to to expel any unwanted air so that it doesn't get into the engine?

any advice is welcome...

[slowcoach]

Worth a check before taking anything apart

What the heck are those red pipes man? Cool.

has Anyone got a better pic of the temp sender for this man?

Its one wire, With a spade terminal on the end, which push fits over the sender end, under the red pipe and blue circle in the above pics

[Jim D]

Interesting, i did see two of those opposite each other near where my picture is.

Well if that isn't it, then what on earth is that thing which is broken in my picture? I haven't been able to find anything that looks like that on the Internet.

I am properly stumped, also I did yank it it and now it's a bit messed up and worried it might start leaking unless I get a new one.

Anyone seen anything that looks like that?

Thanks

James

[Oldiebut goodie]

I'm confused - no doubt you are, that pic above isn't even a diesel let alone a AFN!

[Oldiebut goodie]

Just replace the sensor with a new one, if you plug the new one in quick you will lose next to no coolant and air won't get in as the coolant is coming out! You may have to top up the expansion tank a little.

[VW T25 Feuerwehr]

Worth a check before taking anything apart

What the heck are those red pipes man? Cool.
[ /quote]

New silicone hoses from SFS via Brickwerks

I'm confused - no doubt you are, that pic above isn't even a diesel let alone a AFN!

Thought the wire I highlighted was on the AFN aswell?

[Oldiebut goodie]

It's here:

[Oldiebut goodie]

I would replace that plastic coolant flange for a metal one as they don't seem to have a very long life. http://www.brickwerks.co.uk/index.php/t ... alloy.html

[Jim D]

Right, so managed to take out the old sensor and it looks as thought the people who originally changed the engine used an older sensor stuck into the casing of a newer sensor to fit into the correct place. It only had one pin which has snapped off. It looks as though the wire attached to it was brown with a red strip. The was also a red and yellow wire attached to another sensor which I believe it one for the gauge.

How would I attach this to a new sensor as its only one wire and does anyone have any suggestions on what sensor to buy.


Thanks

James

[Oldiebut goodie]

You should have three sensors - two at the rear of the cylinder head on the outlet flange there, one on that flange that you are looking at - replace with one from Brickwerks http://www.brickwerks.co.uk/index.php/t ... ew-in.html along with the metal flange as above. Around £10 for the two so won't break the bank!

I presume that the plastic housing is for one of these http://www.brickwerks.co.uk/index.php/t ... green.html type of sensor. Looks as though you are lucky that you were rooting about there - that looks a right bodge for the sake of spending £10 to fix it correctly.

[Jim D]

Excellent, thank you so much for this information, This is exactly what I'm getting.

I only have one kore question (at the moment ) if you would be so kind, So at the moment, I only have the one yellow and red wire for the sensor. If I get 2 pin, is there the other end (the male part) does this need two wires? I'm sorry if this seems like a dumb question, where would this other wire come from or would I not need it.

Thanks

James

[Oldiebut goodie]

Are your other two sensors connected?
Usually the two pin sensors need two connectors as there is no earth connection via the housing whereas the single pin gets its earth through the metal coolant flange.
From the Wiki ^^^^^ above:

wiring colours / function:

Browns are Earths.

The thickest (10 gauge)red goes from the alternator to the positive on the battery black live with ignition fuel cut of solenoid on the fuel pump.

feed to glow plugs from the glow plug relay is red ( 4 gauge)

white/blue temperature sender for glow plugs

brown/red feed to temperature sensor for the auxiliary pump and the high current side of the aux pump relay (inside junction box comes from glow plug relay)

red/black aux pump relay switching side (comes from glow plug relay)

a red is for auxiliary pump positive side and brown/red for the negative.

T7a = 7 pin round connector in the junction box

T7a 7 Oil pressure switch High revs yellow

T7a 6 Red white is for the auxiliary pump solenoid

T7a 5 W connector on alternator (rev counter) is green on the forward end then red white to the alt

T7a 4 earth

T7a 3 blue/green coolant shortage level sensor

T7a 2 yellow/red coolant temperature sender

T7a 1 blue/black is low pressure oil sensor low revs (note same colours used for reverse lights)

T3/1 black to D connector on alternator (charging light on dash)

I highly recommend replacing that plastic flange with the JX/CS metal one and use the JX single terminal sensor - when I got my 1.9 engine that plastic flange was cracked and leaking as was the oil breather one.