C5 II runnig hot (overheating) when towing

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

User avatar
white exec
Moderating Team
Posts: 7445
Joined: 21 Dec 2015, 12:46
Location: Sayalonga, Malaga, Spain
My Cars: 1996 XM 2.5TD Exclusive hatch RHD
1992 BX19D Millesime hatch LHD
previously 1989 BX19RD, 1998 ZX 1.9D auto, 2001 Xantia 1.8i auto
and lots of Rovers before that: 1935 Ten, 1947 Sixteen, 1960 P5 3-litre, 1966 P6 2000, 1972 P6 2000TC, and 1975 P6B 3500S
x 1752

Re: C5 II runnig hot (overheating) when towing

Post by white exec »

Sounding good. What an arrangement! #-o
Chris
User avatar
EDC5
(Donor 2020)
Posts: 1216
Joined: 01 Jul 2017, 21:48
Location: N. Wales
My Cars: Citroen C5 RHR AM6
x 120

Re: C5 II runnig hot (overheating) when towing

Post by EDC5 »

Very interesting! maybe the ECU can choose to increase the engine operating temp to increase efficiency at low engine loads but allow proper cooling when required.

I've always thought PSA vehicles ran too cold, around 80 or so rather than the 90 or so for virtually every other make I've experienced, so this system would appeal to me, if it does indeed work on that principle.
User avatar
Romzi
Posts: 49
Joined: 10 Dec 2012, 14:40
Location: Slovenia (Ljubljana)
My Cars: C5 break II, 2.0 HDI
x 3

Re: C5 II runnig hot (overheating) when towing

Post by Romzi »

white exec wrote: 30 Aug 2018, 20:42 Sounding good. What an arrangement! #-o

:lol:
The "new" system is very much simplified, and exacly the same unit is used on Peugeot, Ford and Volvo (in fact the "same" engine), some Fiat and Lancia engines, so I assume It's good enough for Citroen too.
User avatar
osx
(Donor 2022)
Posts: 761
Joined: 08 Jun 2013, 20:09
Location: Oxford
Lexia Available: Yes
My Cars: GSA X
BX 1.6
C5 X7 Auto
C5 X7x2 Manual
x 15

Re: C5 II runnig hot (overheating) when towing

Post by osx »

Had the alternator belt snap while i was on the motorway. First i got a battery warning, next faulty handbrake warning and finally power steering warning and service lamp.
C5 X7 Exclusive 2.0 HDi Auto
C5 X7 Exclusive 2.0 HDi Manual
User avatar
Romzi
Posts: 49
Joined: 10 Dec 2012, 14:40
Location: Slovenia (Ljubljana)
My Cars: C5 break II, 2.0 HDI
x 3

Re: C5 II runnig hot (overheating) when towing

Post by Romzi »

Some news about my "frog".
It still doesn't run cool enough when in hot weather and towing.
I discovered that only this type of C5 (2.0 HDI 2004-2007) and some P407's have the same cooling fan arrangement.
Stock fan is only 150W rated power, but allmost any other 2.0 HDI on the planet has at least 350W cooling fan, or even two of them. For examle C5 MK1 2.0 HDI ( only 83kw) has 3-speed 500W stock cooling fan for vecihles with AC and about 350W cooling fan if the has no aircon. Xsara 2.0 HDI has 350W cooling fan.
I just think it's bad design!
Newer and stronger cars also have quite higher power rating of cooling fans.
Some aftermarket cooling fans for may car are also much higher power rated, for examle: https://www.autodoc.co.uk/tyc/10280307
In the other hand, there are cooling fans for MK1, which are much cheaper (without fan control module): https://www.autodoc.co.uk/van-wezel/1279864
The question is, can I somehow fool my car too use the older and simpler design (with use of power resistors) without warning light come on? Is engine ECU aware of the speed of cooling fan or it's just giving commands for speed without feedback about waht is really happening to the fan itself?
Does anybody have and is willling to share cooling fan wiring and logic for may car? It's C5 break 2.0 HDI, year 10/2004.
User avatar
GiveMeABreak
Forum Admin Team
Posts: 37015
Joined: 15 Sep 2015, 19:38
Location: West Wales
My Cars: C3 Aircross SUV HDi Flair Peperoncino Red (The Chili Hornet)
C5 X7 2.0 HDi Exclusive Mativoire Beige (The Golden Hornet)
C3 1.6 HDi Exclusive Aluminium Grey (The Silver Hornet)
C5 MK II 2.0 HDi Exclusive Obsidian Black
C5 MK I 2.0 HDi SX Wicked Red
Xantia S2 2.0 HDi SX Hermes Red
C15 Romahome White
XM 2.0 Turbo Prestige Emerald Green Pearlescent
XM 2.0 Turbo Prestige Polar White
XM 2.0 SX Polar White
CX 20 Polar White
GS 1220 Geranium Red
CX 2.4 Prestige C-Matic Nevada Beige
GS 1000 Cedreat Yellow
x 5648

Re: C5 II runnig hot (overheating) when towing

Post by GiveMeABreak »

Not recommended, because the engine ECU and the cooling system is designed to operate specifically in a certain way with the air conditioning ECU and the sensors to obtain optimum cooling - according to the situation. If you start changing the system you will probably end up affecting other parts of the system which can have undesired consequences.

Back in the MK I days some of the petrol fans were 500 and 450 W fans and the 2.2 had 2 x 150W fans - but as time has moved on with Euro standards getting stricter, they needed to reduce electrical power consumed and consequently fuel consumption / emissions - so they redesigned the cooling systems to work in a different way so that they consume less power. Even the later petrol engines had reduced capacity fans - the petrol versions I mentioned earlier were reduced to 160 watt.

In your case (DW10BTED4 138Bhp, build date 2 October 2004) , the fan is 150 Watt, but from build number 11055 (14 February 2007) they did increase it to 160 Watt.
Please Don't PM Me For Technical Help

Marc
User avatar
Romzi
Posts: 49
Joined: 10 Dec 2012, 14:40
Location: Slovenia (Ljubljana)
My Cars: C5 break II, 2.0 HDI
x 3

Re: C5 II runnig hot (overheating) when towing

Post by Romzi »

In your case (DW10BTED4 138Bhp, build date 2 October 2004) , the fan is 150 Watt, but from build number 11055 (14 February 2007) they did increase it to 160 Watt.
I know that, but newer models are again using more power consuming fans.
Also, C8 with the "same" engine and aprox. same age is also using much more powerful fans.
Isn't that strange?
User avatar
GiveMeABreak
Forum Admin Team
Posts: 37015
Joined: 15 Sep 2015, 19:38
Location: West Wales
My Cars: C3 Aircross SUV HDi Flair Peperoncino Red (The Chili Hornet)
C5 X7 2.0 HDi Exclusive Mativoire Beige (The Golden Hornet)
C3 1.6 HDi Exclusive Aluminium Grey (The Silver Hornet)
C5 MK II 2.0 HDi Exclusive Obsidian Black
C5 MK I 2.0 HDi SX Wicked Red
Xantia S2 2.0 HDi SX Hermes Red
C15 Romahome White
XM 2.0 Turbo Prestige Emerald Green Pearlescent
XM 2.0 Turbo Prestige Polar White
XM 2.0 SX Polar White
CX 20 Polar White
GS 1220 Geranium Red
CX 2.4 Prestige C-Matic Nevada Beige
GS 1000 Cedreat Yellow
x 5648

Re: C5 II runnig hot (overheating) when towing

Post by GiveMeABreak »

No, that's strictly not true. It all depends on year, engine type and size and what options they have, FAP for example.

I have the same engine (albeit a bit later ) and that too has the 160W fan.

Only the bigger engines now have the twin fans like the 2.2, 2.7 and 3.0 diesels using the X7 as an example. Even the 3.0 V6 petrol X7 has a 160 watt single fan.

But the C8 production ended 2010 used a lot of the same engines as the older C5, but because it is a people carrier and likely to have additional rear air conditioning and more equipment and be heavier, it has the additional cooling. Look at the new C4 Picassos - these are the latest engines and they only have 140W single fans, with one having a 200W.
Please Don't PM Me For Technical Help

Marc
User avatar
white exec
Moderating Team
Posts: 7445
Joined: 21 Dec 2015, 12:46
Location: Sayalonga, Malaga, Spain
My Cars: 1996 XM 2.5TD Exclusive hatch RHD
1992 BX19D Millesime hatch LHD
previously 1989 BX19RD, 1998 ZX 1.9D auto, 2001 Xantia 1.8i auto
and lots of Rovers before that: 1935 Ten, 1947 Sixteen, 1960 P5 3-litre, 1966 P6 2000, 1972 P6 2000TC, and 1975 P6B 3500S
x 1752

Re: C5 II runnig hot (overheating) when towing

Post by white exec »

It could be that some attention has been paid to fan motor design, to enable great air flows at reduced current demand: 500W (or even 300W, and certainly 300W × 2) is no joke at 12-14v !

That still leaves Romzi's C5 II seemingly under-cooled for towing, assuming everything else (like thermostat and water pump) is working well. 1 × 150W does seem a bit marginal; cabin heater fan could be more 'powerful'!

Marc, could you post a circuit diagram for the car's cooling arrangement, just out of interest?
Chris
User avatar
GiveMeABreak
Forum Admin Team
Posts: 37015
Joined: 15 Sep 2015, 19:38
Location: West Wales
My Cars: C3 Aircross SUV HDi Flair Peperoncino Red (The Chili Hornet)
C5 X7 2.0 HDi Exclusive Mativoire Beige (The Golden Hornet)
C3 1.6 HDi Exclusive Aluminium Grey (The Silver Hornet)
C5 MK II 2.0 HDi Exclusive Obsidian Black
C5 MK I 2.0 HDi SX Wicked Red
Xantia S2 2.0 HDi SX Hermes Red
C15 Romahome White
XM 2.0 Turbo Prestige Emerald Green Pearlescent
XM 2.0 Turbo Prestige Polar White
XM 2.0 SX Polar White
CX 20 Polar White
GS 1220 Geranium Red
CX 2.4 Prestige C-Matic Nevada Beige
GS 1000 Cedreat Yellow
x 5648

Re: C5 II runnig hot (overheating) when towing

Post by GiveMeABreak »

Sure, give me a minute... Also consider the max. towing weights too - we have another member querying the towing weight - who thought is was a bit low - that can cause overheating of course if exceeding limits.
Please Don't PM Me For Technical Help

Marc
User avatar
GiveMeABreak
Forum Admin Team
Posts: 37015
Joined: 15 Sep 2015, 19:38
Location: West Wales
My Cars: C3 Aircross SUV HDi Flair Peperoncino Red (The Chili Hornet)
C5 X7 2.0 HDi Exclusive Mativoire Beige (The Golden Hornet)
C3 1.6 HDi Exclusive Aluminium Grey (The Silver Hornet)
C5 MK II 2.0 HDi Exclusive Obsidian Black
C5 MK I 2.0 HDi SX Wicked Red
Xantia S2 2.0 HDi SX Hermes Red
C15 Romahome White
XM 2.0 Turbo Prestige Emerald Green Pearlescent
XM 2.0 Turbo Prestige Polar White
XM 2.0 SX Polar White
CX 20 Polar White
GS 1220 Geranium Red
CX 2.4 Prestige C-Matic Nevada Beige
GS 1000 Cedreat Yellow
x 5648

Re: C5 II runnig hot (overheating) when towing

Post by GiveMeABreak »

Here you are, (no Particulate Filter on this model either). Note: For the C5 II with DW10BTED4 with no FAP.

Equipment
1513: Cooling Fan Electronic Mixer Unit

Wires
1590: Fan unit relay power supply
1599B: Fan unit diagnostic info
1540B: fan control 1 (-)
B160: To Maxi Fuse
M153: Earth

Image
Please Don't PM Me For Technical Help

Marc
User avatar
myglaren
Forum Admin Team
Posts: 25370
Joined: 02 Mar 2008, 13:30
Location: Washington
My Cars: Mazda 6
Ooops.
Previously:
2009 Honda Civic :(
C5, C5, Xantia, BX, GS, Visa.
R4, R11TXE, R14, R30TX
x 4889

Re: C5 II runnig hot (overheating) when towing

Post by myglaren »

I wonder if it would be feasible to fit an uprated fan?
Bodgery may be called for.
User avatar
Paul-R
Donor 2023
Posts: 6916
Joined: 07 May 2009, 16:24
Location: Wirral, NW England; Vaucluse 84, France
Lexia Available: Yes
My Cars: 2015 1.6 Blue HDi 120 Peugeot 308 Active SW
2013 2.0 HDi 163 C5 Exclusive Tourer
2003 2.0 HDi 110 C5 Exclusive Estate (Gone)
2001 2.0 HDi 90 Xsara Estate (Gone)
x 1369

Re: C5 II runnig hot (overheating) when towing

Post by Paul-R »

myglaren wrote: 05 Jul 2019, 19:01I wonder if it would be feasible to fit an uprated fan?
Bodgery may be called for.
Feed a heavier duty fan through a fused relay direct to the battery. This will only work if it's single speed though. And there's always the complication that whatever ECU is looking after cooling might measure current pull and a relay coil would be significantly less than a fan motor.

Is there scope for a second fan on the radiator?
As I get older I think a lot about the hereafter - I go into a room and then wonder what I'm here after.

Inside every old person is a young person wondering what the hell happened.

"Trying is the first step towards failure" ~ Homer J Simpson​
User avatar
GiveMeABreak
Forum Admin Team
Posts: 37015
Joined: 15 Sep 2015, 19:38
Location: West Wales
My Cars: C3 Aircross SUV HDi Flair Peperoncino Red (The Chili Hornet)
C5 X7 2.0 HDi Exclusive Mativoire Beige (The Golden Hornet)
C3 1.6 HDi Exclusive Aluminium Grey (The Silver Hornet)
C5 MK II 2.0 HDi Exclusive Obsidian Black
C5 MK I 2.0 HDi SX Wicked Red
Xantia S2 2.0 HDi SX Hermes Red
C15 Romahome White
XM 2.0 Turbo Prestige Emerald Green Pearlescent
XM 2.0 Turbo Prestige Polar White
XM 2.0 SX Polar White
CX 20 Polar White
GS 1220 Geranium Red
CX 2.4 Prestige C-Matic Nevada Beige
GS 1000 Cedreat Yellow
x 5648

Re: C5 II runnig hot (overheating) when towing

Post by GiveMeABreak »

Romzi wrote: 05 Jul 2019, 13:25 Is engine ECU aware of the speed of cooling fan or it's just giving commands for speed without feedback about waht is really happening to the fan itself?
Does anybody have and is willling to share cooling fan wiring and logic for may car? It's C5 break 2.0 HDI, year 10/2004.
To answer your questions:

Wiring Diagram is now up.

As for what is happening:
You have a 2 speed fan on your vehicle (the 3 speed version was fitted to some ES and EW petrol engines).

The engine ECU determines the fan speed based on information from
  • The Engine Coolant Temperature Sensor (1220 on the diagram)
  • The Air Conditioning Circuit pressure measured by sensor
  • The temperature of the Auto Gearbox (where fitted)
The engine ECU controls the slow and fast speeds.

Between 97°C and 105°C, the engine ECU commands the chopper control on a staged basis
If the temperature reaches 105°C, the engine ECU commands the cooling fan to operate at fast speed

As far as the Air conditioning goes a sensor (Aircon Fluid Pressure Sensor 8009). The linear pressure sensor allows the pressure of the cooling circuit to be measured, which enables the engine ECU to control the slow or fast speed of the fan unit.
Please Don't PM Me For Technical Help

Marc
User avatar
GiveMeABreak
Forum Admin Team
Posts: 37015
Joined: 15 Sep 2015, 19:38
Location: West Wales
My Cars: C3 Aircross SUV HDi Flair Peperoncino Red (The Chili Hornet)
C5 X7 2.0 HDi Exclusive Mativoire Beige (The Golden Hornet)
C3 1.6 HDi Exclusive Aluminium Grey (The Silver Hornet)
C5 MK II 2.0 HDi Exclusive Obsidian Black
C5 MK I 2.0 HDi SX Wicked Red
Xantia S2 2.0 HDi SX Hermes Red
C15 Romahome White
XM 2.0 Turbo Prestige Emerald Green Pearlescent
XM 2.0 Turbo Prestige Polar White
XM 2.0 SX Polar White
CX 20 Polar White
GS 1220 Geranium Red
CX 2.4 Prestige C-Matic Nevada Beige
GS 1000 Cedreat Yellow
x 5648

Re: C5 II runnig hot (overheating) when towing

Post by GiveMeABreak »

Paul-R wrote: 05 Jul 2019, 19:26
myglaren wrote: 05 Jul 2019, 19:01I wonder if it would be feasible to fit an uprated fan?
Bodgery may be called for.
Feed a heavier duty fan through a fused relay direct to the battery. This will only work if it's single speed though. And there's always the complication that whatever ECU is looking after cooling might measure current pull and a relay coil would be significantly less than a fan motor.

Is there scope for a second fan on the radiator?
Single fan only and no room for another fan in the housing, plus this is a twin speed system.
Please Don't PM Me For Technical Help

Marc
Post Reply