Hello, i have had my Felicia for over 2 years now, and since then i have had a few problems with it starting, i would go into it and when i tried to start it, it would not light up the glow plug light, after digging around some old posts on the forums i changed the temperature sensor, this fixed the problem for a couple of days but eventually it started doing it all over again, i took it to an eletrician and after him gaving it a look it starts everytime when it's cold, but after being hot it won't start.

Right after i changed the temperature sensor the truck started getting hotter than it did before, climbing over to close to the 110Cº mark and no fan kicking in i have no clue to what else i could do to fix it.

In summary:
New temp sensor, temperature got way hotter and won't start when the engine is hot

New sensor could be faulty, the cheap Chinese ones can go kaput real quick.

You could cross check with a laser thermometer pointed at the top hose that the new sensor is giving correct readings.

The sensor has 2 circuits, 1 supplies temp info to the diesel ECU, the other supplies info for the dashboard temp gauge. One could be malfunctioning whilst the other is working ok.

Also correct me if I'm wrong but doesn't the diesel have a auto activated glow plug system that starts when the drivers door is opened, but cuts out if the door is opened and closed repeatedly to stop the battery being drained of power.

4 minutes ago, R_U_AFA said:

New sensor could be faulty, the cheap Chinese ones can go kaput real quick.

You could cross check with a laser thermometer pointed at the top hose that the new sensor is giving correct readings.

The sensor has 2 circuits, 1 supplies temp info to the diesel ECU, the other supplies info for the dashboard temp gauge. One could be malfunctioning whilst the other is working ok.

Also correct me if I'm wrong but doesn't the diesel have a auto activated glow plug system that starts when the drivers door is opened, but cuts out if the door is opened and closed repeatedly to stop the battery being drained of power.

As for the sensor i am at my 3rd one i don't think they would all be bad.
The wiring for the sensor was all revised 2 times now by an auto eletrician soo that's good too.

The problem is once the truck runs for a while and gets to operating temperature it won't turn the plugs anymore and won't start, this was told to me, as being normal and that the truck should actually still start since it is indeed still hot but it just cranks, if i unplug the temp sensor it forces the plugs they turn on and the truck starts like nothing.

As for the temperature it still raises to about 105 ish and i don't hear the fan kicking in, if i park the truck and let it run at 95º it turns the fan on.

 

11 hours ago, qrylix said:

As for the temperature it still raises to about 105 ish and i don't hear the fan kicking in, if i park the truck and let it run at 95º it turns the fan on.

 

The radiator fan switch is OK?

Connections are tight?

 

Coolants sensors cables and pins checked?

I had a problem in the past with mine.

 

https://imgur.com/f1OlmZj

 

https://imgur.com/IfK1GYb

 

Coolant sensor ''base'' is clear from detritus?

Put your finger inside,check and with a piece of cloth clear the whole area, in the past some powder from a previous additive was causing the dashboard gauge to show false indications.

I have not checked the radiator switch, but everytime i stop the truck it turns on after a few seconds no problem, connections are tight yes.

The coolant sensor was all rewired from new soo that would not be the problem.

Yes the sensor is new, already had 3 installed.

Check with VCDS to see any error codes? 

An ECU restart by yourself maybe will help.

Being the Felly OBD1, do you have any VCDS that i could get to read and clear the codes?

7 minutes ago, qrylix said:

Being the Felly OBD1, do you have any VCDS that i could get to read and clear the codes?

 

Plain OBD is what we have.

Any VW Group repair-store will have a laptop with the programme inside, even an old style error scanner will do for Felicia.

 

Why don't you try an ECU reset by yourself, maybe there is an error kept in the memory and cause you the problem, maybe when erased everything will back to normal.

You can do a reset from the ECU plugs or the battery or from the fuses inside, it's easy.

Having not worked on a diesel, I can't be too much help.

But you could try spraying some easy start gas into the intake when hot cranking without the glow plugs operating situation to see if it will start then.