Technical Ducato 2.8 idTD Temp Gauge and Fan issues.

[GaryGavlaar]

Hi all,

After some words of wisdom on this issue I have if possible?

Like others I've never heard the fans kick in, but what I've also noticed is the temp gauge in the van never hits that half way (90c) mark. Is this normal? It gets close when climbing or under pressure on a hot day, still no fans though.

Fans work under temp 12v load, so fans not seized. So, wondering if there is a temp sensor fault somewhere.

I've looked on eper, and can see what looks like 2 holes in the side of the thermostat for 2 separate sensors, however mine only has one of the holes populated with a sensor, which i think is something like https://coastalmotorhomes.co.uk/fia...lay-coolant-temp-sender-sensor-504127558.html.

The one circled in this picture isn't there, but I also cant see a cable anywhere that would connect to it so could be a red herring

On the two pins of the sensor that is there, when the van is running, I have 14.5v at one and about 9v at the other.

If i short the connectors pins to earth I can see that one connector controls the temp gauge in the dash and the other the water temp warning light. Both seem to work. However shorting either of them still doesn't make the fans kick in. This has me thinking that even if this temp sensor is faulty, this isn't the cause of the fans not kicking in, however it could be the cause of the temp gauge not reaching 90c maybe.

Any words of wisdom or advice on what i can do to try and diagnose the fans issue, would be great.

Cheers all

 

[bugsymike]

Hi all,

After some words of wisdom on this issue I have if possible?

Like others I've never heard the fans kick in, but what I've also noticed is the temp gauge in the van never hits that half way (90c) mark. Is this normal? It gets close when climbing or under pressure on a hot day, still no fans though.

Fans work under temp 12v load, so fans not seized. So, wondering if there is a temp sensor fault somewhere.

I've looked on eper, and can see what looks like 2 holes in the side of the thermostat for 2 separate sensors, however mine only has one of the holes populated with a sensor, which i think is something like https://coastalmotorhomes.co.uk/fia...lay-coolant-temp-sender-sensor-504127558.html.

The one circled in this picture isn't there, but I also cant see a cable anywhere that would connect to it so could be a red herring

View attachment 471152

On the two pins of the sensor that is there, when the van is running, I have 14.5v at one and about 9v at the other.

If i short the connectors pins to earth I can see that one connector controls the temp gauge in the dash and the other the water temp warning light. Both seem to work. However shorting either of them still doesn't make the fans kick in. This has me thinking that even if this temp sensor is faulty, this isn't the cause of the fans not kicking in, however it could be the cause of the temp gauge not reaching 90c maybe.

Any words of wisdom or advice on what i can do to try and diagnose the fans issue, would be great.

Cheers all

Quite possible the thermostat is struck open or opening earlier.
According to my data the thermostat opens at 80 Degrees Centigrade on those engines, so roughly just under the centre of the temp gauge.
Ideally it should reach this within under 10 minutes of driving.
If it does that and no loss of coolant etc. and a good pressure cap on the expansion tank holding pressure it is quite possible the engine never reaches a high enough temp to get the fan to kick in.
If the system is all good as I have described then you can give it a test by putting a board across the front of the radiator and whilst stationary fix the accelerator to around 1500rpm, it doesn't need to be screaming, just enough for the engine to be working a little, then watch the gauge, it probably will not activate the radiator fan until around 3/4 of the way up the temp. gauge.
Don't let it go much above that as a safety margin and keep checking under the bonnet to see if fan cutting in, also incase a water leak develops.
Recently I was running a Citroen van as I described , temp was well within margin, but suddenly I saw a large water leak as a hose at the back of the engine split, so I was glad it happened whilst testing and not on the road as it was a large leak from a very soft hose.
It was a pig to change, but peace of mind when done.

 

[airwave]

Hi all,

After some words of wisdom on this issue I have if possible?

Like others I've never heard the fans kick in, but what I've also noticed is the temp gauge in the van never hits that half way (90c) mark. Is this normal? It gets close when climbing or under pressure on a hot day, still no fans though.

Fans work under temp 12v load, so fans not seized. So, wondering if there is a temp sensor fault somewhere.

I've looked on eper, and can see what looks like 2 holes in the side of the thermostat for 2 separate sensors, however mine only has one of the holes populated with a sensor, which i think is something like https://coastalmotorhomes.co.uk/fia...lay-coolant-temp-sender-sensor-504127558.html.

The one circled in this picture isn't there, but I also cant see a cable anywhere that would connect to it so could be a red herring

View attachment 471152

On the two pins of the sensor that is there, when the van is running, I have 14.5v at one and about 9v at the other.

If i short the connectors pins to earth I can see that one connector controls the temp gauge in the dash and the other the water temp warning light. Both seem to work. However shorting either of them still doesn't make the fans kick in. This has me thinking that even if this temp sensor is faulty, this isn't the cause of the fans not kicking in, however it could be the cause of the temp gauge not reaching 90c maybe.

Any words of wisdom or advice on what i can do to try and diagnose the fans issue, would be great.

Cheers all

Yes , i had exactly the same when i brought my van back in 2016 . Now bearing in mind , my van only has something like 46000 on the clock , half way is about normal . Never heard the fans , never really needed them . Then on one particularly hot day , just outside Hastings in Sussex it changed , it started to climb in traffic . I watched it like a hawk , and waited for the fans to kick in , and yep they never did . So i turned on the heater , and cooled the motor that way . Oh and yes it was hot air coming out , not a false reading . It was then i realised i'd never actually heard the fans operating at all , so i suspected there could be a possible fault . I took a quick look at the camp site where i was staying , but as i neither had any tools or parts it was purely a look to confirm the layout .

Right so that's enough of that , the long and short of it is , i changed the fan thermostat in the radiator . Easy to find inside front nearside bottom of the rad . I hear the fans regularly now , it only has to climb a tad , and bang there's the fan . It's set for something like 88 degrees if i remember correctly . Access to the thermostat is excellent from underneath , unless you have fitted a full belly pan like me (very first thing i brought for my van) , but be warned you will lose most of your coolant . Don't mess around with it , just change it out for a new one , it's literally not worth the hassle . There's two types , i think a black one , and a blue . Idtd you want the blue , it's only for independent activation , you have two and they operate independently . The black has two wires where the blue has three . I can't actually remember what temp ratings they are , but if you need to know , i can find them without many problems .
Now a couple of notes on the coolant , first off there's two types , blue , and pink . You want the pink , don't worry about getting the Fiat recommended stuff , its all about money between Fiat and Petronas . To be frank , it's bloody expensive anyway , just don't ask me how i know . I would also recommend you use distilled water too , for some reason it works better than tap water in a cooling system , cleaner too . I always go a 50/50 mix , but your van , your rules . Just don't forget the winter , and a 50/50 mix will protect you down to some silly temperature like -25 , -30 .
Now finally filling , fairly easy , but be aware there is a breather/bleed vent on the engine firewall . Should be a black plug close to the heater inlet/out let hoses , about mid way across the firewall . Open it to start , and obviously close it when coolant comes out .

Okay Gary .

 

[airwave]

Good evening Mike .

 

[bugsymike]

Good evening Mike .

Just going to drop car back to daughter, I will try and continue conversation later.

 

[airwave]

Just going to drop car back to daughter, I will try and continue conversation later.

Yeah okay mate .

 

[GaryGavlaar]

Yes , i had exactly the same when i brought my van back in 2016 . Now bearing in mind , my van only has something like 46000 on the clock , half way is about normal . Never heard the fans , never really needed them . Then on one particularly hot day , just outside Hastings in Sussex it changed , it started to climb in traffic . I watched it like a hawk , and waited for the fans to kick in , and yep they never did . So i turned on the heater , and cooled the motor that way . Oh and yes it was hot air coming out , not a false reading . It was then i realised i'd never actually heard the fans operating at all , so i suspected there could be a possible fault . I took a quick look at the camp site where i was staying , but as i neither had any tools or parts it was purely a look to confirm the layout .

Right so that's enough of that , the long and short of it is , i changed the fan thermostat in the radiator . Easy to find inside front nearside bottom of the rad . I hear the fans regularly now , it only has to climb a tad , and bang there's the fan . It's set for something like 88 degrees if i remember correctly . Access to the thermostat is excellent from underneath , unless you have fitted a full belly pan like me (very first thing i brought for my van) , but be warned you will lose most of your coolant . Don't mess around with it , just change it out for a new one , it's literally not worth the hassle . There's two types , i think a black one , and a blue . Idtd you want the blue , it's only for independent activation , you have two and they operate independently . The black has two wires where the blue has three . I can't actually remember what temp ratings they are , but if you need to know , i can find them without many problems .
Now a couple of notes on the coolant , first off there's two types , blue , and pink . You want the pink , don't worry about getting the Fiat recommended stuff , its all about money between Fiat and Petronas . To be frank , it's bloody expensive anyway , just don't ask me how i know . I would also recommend you use distilled water too , for some reason it works better than tap water in a cooling system , cleaner too . I always go a 50/50 mix , but your van , your rules . Just don't forget the winter , and a 50/50 mix will protect you down to some silly temperature like -25 , -30 .
Now finally filling , fairly easy , but be aware there is a breather/bleed vent on the engine firewall . Should be a black plug close to the heater inlet/out let hoses , about mid way across the firewall . Open it to start , and obviously close it when coolant comes out .

Okay Gary .

Is that this little thing?

 

[GaryGavlaar]

Quite possible the thermostat is struck open or opening earlier.
According to my data the thermostat opens at 80 Degrees Centigrade on those engines, so roughly just under the centre of the temp gauge.
Ideally it should reach this within under 10 minutes of driving.
If it does that and no loss of coolant etc. and a good pressure cap on the expansion tank holding pressure it is quite possible the engine never reaches a high enough temp to get the fan to kick in.
If the system is all good as I have described then you can give it a test by putting a board across the front of the radiator and whilst stationary fix the accelerator to around 1500rpm, it doesn't need to be screaming, just enough for the engine to be working a little, then watch the gauge, it probably will not activate the radiator fan until around 3/4 of the way up the temp. gauge.
Don't let it go much above that as a safety margin and keep checking under the bonnet to see if fan cutting in, also incase a water leak develops.
Recently I was running a Citroen van as I described , temp was well within margin, but suddenly I saw a large water leak as a hose at the back of the engine split, so I was glad it happened whilst testing and not on the road as it was a large leak from a very soft hose.
It was a pig to change, but peace of mind when done.

Yeah mine never gets to half way. I drove to Whitby this past week and did a few climbs and it gets hot to the point you can smell that hot water smell, but still only just gets to half way, then once the climb is over its back down a couple of notches. Is there anything other than that one pin on the temp sensor on the thermostat that would effect the temp gauge needle? is it a sum/max of multiple sensors by any chance?

I've opened up the little control box on the rad and tested the two relays switch ok when voltage applied. Both good.

I've also placed a jumper cable across the two terminals that are joined when voltage applied, and both fans kick in fine.

Wondering if there is more than one problem here.

 

[airwave]

Is that this little thing?

View attachment 471165

I struggled there , till i realised it was upside down . Yes mate that's the thing and as you can see , it's blue . Your first picture also shows the three wires , they run up to a little black box , on the right hand fan shroud . That's where your relays are .

 

[GaryGavlaar]

I struggled there , till i realised it was upside down . Yes mate that's the thing and as you can see , it's blue . Your first picture also shows the three wires , they run up to a little black box , on the right hand fan shroud . That's where your relays are .

See prev post where I've talked about testing them relays. They seem all good........from my basic testing at least.

 

[airwave]

See prev post where I've talked about testing them relays. They seem all good........from my basic testing at least.

Yeah i noticed you replied to Mike after i posted . He's done a runner right now , but i doubt he will be long . See post 5 .

Personally i wouldn't be to worried about a low temp reading , you may have a cool running engine . I've had two , one in the past , and my current van is another . Bloody cold in the winter , but a boon in the summer . Oh and i'm talking about a small van , not the motorhome . Suzuki ! .

The activation circuit operates on the earth , not positive side of the circuit , i think due to the high currents floating about . So power there or not makes no difference . I've just fitted a manual override to my system , to run alongside the automatic activation , and had to switch to earth . Fuse is something like 30 amps . I believe that's under the bonnet as well , but i can't confirm that .
As for the senders , you actually have two on the Idtd , not quite sure why . I've just done a complete cooling system rebuild , and found them then . Trouble is the new one's are advertised in German , and errr , i can't speak German . Google translate comes up with some weird conversion that don't make sense . I suspect one could be for your gauge , and the other for the warning light , but i can't say for sure . Just don't ask which is which either .

 

[GaryGavlaar]

Yeah i noticed you replied to Mike after i posted . He's done a runner right now , but i doubt he will be long . See post 5 .

Personally i wouldn't be to worried about a low temp reading , you may have a cool running engine . I've had two , one in the past , and my current van is another . Bloody cold in the winter , but a boon in the summer . Oh and i'm talking about a small van , not the motorhome . Suzuki ! .

The activation circuit operates on the earth , not positive side of the circuit , i think due to the high currents floating about . So power there or not makes no difference . I've just fitted a manual override to my system , to run alongside the automatic activation , and had to switch to earth . Fuse is something like 30 amps . I believe that's under the bonnet as well , but i can't confirm that .
As for the senders , you actually have two on the Idtd , not quite sure why . I've just done a complete cooling system rebuild , and found them then . Trouble is the new one's are advertised in German , and errr , i can't speak German . Google translate comes up with some weird conversion that don't make sense . I suspect one could be for your gauge , and the other for the warning light , but i can't say for sure . Just don't ask which is which either .

Two separate sensors you mean? I only seem to have one, but it had two pins, one which controls the temp light and one which controls the temp gauge. This sensor sits in the side of the thermostat housing.

With regards to a cool running engine, where would you expect the temp gauge to be reading when the fans kick in? Or is there no link betrween the gauge and the fans?

Oh and another one... I can't seem to find that bleed screw on the engine firewall, any pointers on what it looks like?

Many thanks for all this info.

 

[bugsymike]

I'm free.
You guys probably are more familar with Ducato wiring than me.
Although similar engines the Iveco Dailys were more my flavour, although I did fit a 1997 2.8iDT 122hp from a Ducato Maxi van in my boat and tweaked the engine to give more power.
Incidentally temp gauge on that ran at normal centre of gauge, I make a thing of having a good thermostat as engines runs more efficiently and quieter and oil stays cleaner longer as less condensation from cold engine.

 

[bugsymike]

Yeah mine never gets to half way. I drove to Whitby this past week and did a few climbs and it gets hot to the point you can smell that hot water smell, but still only just gets to half way, then once the climb is over its back down a couple of notches. Is there anything other than that one pin on the temp sensor on the thermostat that would effect the temp gauge needle? is it a sum/max of multiple sensors by any chance?

I've opened up the little control box on the rad and tested the two relays switch ok when voltage applied. Both good.

I've also placed a jumper cable across the two terminals that are joined when voltage applied, and both fans kick in fine.

Wondering if there is more than one problem here.

As far as I know the actual temp gauge especially on older vehicles is just a single wire to the gauge.
Obviously the fan temp sensor needs to go through the relays for the higher amperage required to activate the fans.

 

[bugsymike]

I even test the thermostats in a saucepan of water with a thermometer to ensure opening at correct temp and closing again as temp drops.

 

[GaryGavlaar]

I just had a thought. I unplugged the radiator fan switch. I joined two of the pins with a small cable and one of the fans kicked in even with the ignition off, so assume fans should even run with ignition off if temp is high. However, when i then tried another two pins, expecting the other fan to kick in, it didn't.

I even test the thermostats in a saucepan of water with a thermometer to ensure opening at correct temp and closing again as temp drops.

Im not familiar with how a thermostat works. Would I need to remove that whole thermostat housing for this, or is it the round bit thats screwed into the housing that you would remove and test in water?

 

[airwave]

Two separate sensors you mean? I only seem to have one, but it had two pins, one which controls the temp light and one which controls the temp gauge. This sensor sits in the side of the thermostat housing.

With regards to a cool running engine, where would you expect the temp gauge to be reading when the fans kick in? Or is there no link betrween the gauge and the fans?

Oh and another one... I can't seem to find that bleed screw on the engine firewall, any pointers on what it looks like?

Many thanks for all this info.

Sorry i'm cooking dinner , i've got an elderly parent here , and it's become a bit beyond her nowadays . I'm slowly taking over the reins , she's 87 , and frankly can't have much longer to go .

Right well on the thermostat housing attached to the engine , there's one on the front , and then round the back is another . It's between the firewall , and thermostat housing . The back one is difficult to get to , but i see it all the time . Chances are it's because i know it's there . I really don't know which is which , i tried to figure it out when i was rebuilding the cooling system couple of years ago .

Cool running engine , well that depends on the motor . My current van barely gets off the peg during the winter , only about quarter of the way during summer . Unless i've got my foot planted . Previous van barely got off the peg , summer or winter . Now a diesel engine gets a bit erratic when it runs hot , they will start using oil , but they run slightly cool to a petrol anyway . If you getting just under half , i would be happy with that .

Now the bleed screw . Look for the heater hoses , and follow to where they pass though the firewall . It should be below those , if i remember correctly it has a cross head screw look , but it quite large .

 

[GaryGavlaar]

Hey don't worry, you do what you need to do. Reply when you have time.

Are these the switches i need?

https://www.onlinecarparts.co.uk/car-brands/spare-parts-fiat/ducato-platform-chassis-230/11845/10434/temperature-switch-radiator-fan.html

 

[airwave]

and one of the fans kicked in even with the ignition off,

It will do , the cooling fans have a permanent supply , they are controlled by the radiator thermostat via a relay . This is why so many people have problems and report a fan still working , or start working after the engine has been turned off . There are numerous threads on exactly that subject on here , with at least 2 new ones a year . It's a very common fault .
I suspect even the secondary circuit has a permanent positive feed , but the earth must be controlled , and this i believe is it's achilles heel . In a normal circuit the positive is switched , if this wire is run to earth , the circuit simply doesn't work , blowing the fuse in the process . Take a controlled earth and switch it , and what happens here should it be run to earth , the circuit will operate , even with the keys in your pocket . I dunno why it's done that way , but the Europeans are not the only ones , America is the same . There must be a reason , i just don't know what it is .

Are these the switches i need?

Yeah that the one , first one , even has the temps listed for ya . See what i mean , at that price they simply ent worth the hassle .

Im not familiar with how a thermostat works.

Basically on the top of the thermostat housing , you should see a domed cover held down with two bolts , sometimes three . Remove those bolts and then the cover . The thermostat is a separate unit underneath , you need to remove that , but here again i never bother . I just sling it and fit a new one , they ent worth the hassle for their price . But i will say this , it's very rare for an actual thermostat to go wrong . It does happen , just i've never actually had one .

Hey don't worry, you do what you need to do.

Thanks mate , i'm actually off work (holiday) at the minute , and yes i do know it's the weekend , but i've got no idea how this is gonna work when i do eventually go back . Being off since mid June , and not due back till September . Think i'm gonna have to work a short week to cover it all . She spends 22 outta 24 hours asleep , even struggles to do the shopping now . I didn't realise it was this serious , but like i said i'm gradually taking over .

 

[Communicator]

I just had a thought. I unplugged the radiator fan switch. I joined two of the pins with a small cable and one of the fans kicked in even with the ignition off, so assume fans should even run with ignition off if temp is high. However, when i then tried another two pins, expecting the other fan to kick in, it didn't.


Im not familiar with how a thermostat works. Would I need to remove that whole thermostat housing for this, or is it the round bit thats screwed into the housing that you would remove and test in water?

Hi Gary,
I have been following your conversation. Mike will have retired to bed, and Airwave is busy. May I help?

1. Shorting the pins. At the first attempt you struck lucky, and shorted the earth connection to pin operating one of the fan relays. At second attempt you may just have connected the negative ends of the two relays together. As you observed nothing would happen. Yes some fans are allowed to run with ignition off, to ensure that a hot engine is cooled sufficiently. Other fan may need ignition on. This different method of connection explains why the contacts of the radiator mounted thermostatic switch are on the negative side of the relay coils.

2. Thermostat operation. It is in fact a temperature operated valve. Modern versions are operated by a wax filled capsule. The wax is mixed so as to melt at the desired temperature. The wax expands as it melts and opens the valve, allowing the coolant to flow from the engine and through the radiator.

To access the thermostat you would have to remove the thermostat housing. The part that screws in on the 2.8idTD is the sensor for the gauge, combined with the thermostatic switch for the warning light. I am puzzled by Airwave's statement that he has two sensors in his thermostat housing. This does apply to my 2.8jtd, where the second sensor is forthe ECU, which controls the fan relays nstead of your radiator mounted switch.

Hope that helps.