1986 1.6TD JX Coolant Senders

[grenjs]

Evening!

As far as I know there are 3 coolant senders in the cooling system on these engines.

(1) is located in the hose housing on the top/side of the cylinder head [pipe goes to radiator at front].
(2) is on the top side of the coolant hose coming out of the back of the cylinder head [pipe goes to heater].
(3) is on the bottom side of the coolant hose coming out of the back of the cylinder head [pipe goes to heater].

Can anyone tell me exactly what each of these senders control?

I'm guessing sender (2) VW Part: 049 919 501 is for the glow-plug light - e.g. it tell the glow-plug relay how long to heat the plugs for ... but it may serve others purposes - temp gauge?

Had a good search on the forum and in the wiki but can't find anything which helps.

Thanks.

[dave friday]

Found in the "Wiki"..2 and 3 are for temperature gauge and glow plug.so the last one is for the auxiliary water pump.

[grenjs]

Found in the "Wiki"..2 and 3 are for temperature gauge and glow plug.so the last one is for the auxiliary water pump.

Great find. Thanks! I looked and couldn't find it. Can you post me a link to the wiki entry?

[dave friday]

5.4
then a little way down;Diesel cylinder inst senders [including a picture]
Are you having a problem,if so what is it?

[grenjs]

5.4
then a little way down;Diesel cylinder inst senders [including a picture]
Are you having a problem,if so what is it?

Cheers. It's running a little hot, so want to change out the 3 senders, but I am interested to know what each of them do.

[grenjs]

Guessed right for sender 2, but no mention of sender No.1.

[dave friday]

The senders on the heater flange are both the same part and vary from 1200ohms [cold] to 25/50ohms [hot]
The one on the flange on the side of the head is a switch that switches on when/if the water gets to 104deg c !!
Does the rad fan come on?

[grenjs]

The senders on the heater flange are both the same part and vary from 1200ohms [cold] to 25/50ohms [hot]
The one on the flange on the side of the head is a switch that switches on when/if the water gets to 104deg c !!
Does the rad fan come on?

But what does that sender switch on/off?

Re Rad fan - that's my next port of call. The previous owner disconnected the rad fan from the relay (has no relay at present!) and has it wired to an on/off switch on the dash. Probably because the Thermo-switch on the rad failed or it burnt out the relay. So tomorrow it'll be re-wired back to normal.

However, the temp creeps up to quickly for my liking, so starting with the basics by replacing the senders.

Have read about other possibilities such as the voltage regulator on the rear of the temp gauge, but don't want to get too far ahead of myself. Need to understand what the sensors do, re-wire then fan with new switch and take it from there. Wood for the tree approach.



Thanks for pointing me to that picture.

[dave friday]

The switch turns on the auxiliary water pump[should be on the fire wall on the front of the engine compartment]

[grenjs]

The switch turns on the auxiliary water pump[should be on the fire wall on the front of the engine compartment]

Great - thanks. Will be checking that one out too to make sure it's working.

Cheers for the very helpful replies. Think everything is in hand - for the time being!

[syncroandy]

Looks like you're sorted but in case its useful see below copied/pasted from my notes:

VW Transporter 80-92
JX engine temperature sender data
From chassis ref. 24-K-064851

Ref Description Wire colour Sender part number Colour

F95 Thermoswitch for coolant circulation run-on Brown/Red & Brown 251 919 369 F Brown
G27 Sensor for engine temperature (glow plugs) Blue/White & Brown 251 919 501 A, 251 919 501 D Black
G2 Coolant temperature gauge sender Yellow/Red & Brown 251 919 501 A, 251 919 501 D Black

[grenjs]

Looks like you're sorted but in case its useful see below copied/pasted from my notes:

VW Transporter 80-92
JX engine temperature sender data
From chassis ref. 24-K-064851

Ref Description Wire colour Sender part number Colour

F95 Thermoswitch for coolant circulation run-on Brown/Red & Brown 251 919 369 F Brown
G27 Sensor for engine temperature (glow plugs) Blue/White & Brown 251 919 501 A, 251 919 501 D Black
G2 Coolant temperature gauge sender Yellow/Red & Brown 251 919 501 A, 251 919 501 D Black

Thanks for that. Very useful info.