Daf 105 cooling problem

I’ve got a problem with a 105 no cooling down once its got hot ,am not worried about it getting hot as its only doing it loaded on a climb ,in the garage we blocked the front of the rad to make it get hot and we had it plugged in so it was showing the temp we got it upto 100 degrees and the fan kicked into the higher speed as it should happy days then the fan slowed down to its normal speed as the temp came back down . the auto Elec said that the ecu is still asking for the higher speed but the fans not giving it ,all fingers now point to the viscous coupling ,now here’s where it went wrong the temp started to climb again as we wanted it to ,it got to 100 .then 101 then 103 degrees and nothing the fan wouldn’t speed up ,the ecu should be telling it again to kick in but it didn’t do anything other than spin at its normal speed we’ve tested the loom it appears ok changed the temp sensor on the off side of the engine and the vicious coupling appears to be working and its only a month old ,any ideas as am vor again til I can get it sorted.

Is the viscuous coupling is getting adequate airflow? Did you block off the radiator completely or leave a hole in line with the coupling? Are the fins of the radiator choked with leaves, mud, oil and dirt between it and the intercooler?

Have you physically checked the fan wiring loom where it comes out of the rubber support tube?

Wiring has been checked and it working intermittently it just would not kick in to a higher speed the 2nd time when it was supposed to as the temp increased,its more a case of the temp was high over 100 degrees according to the computer diagnostics and it didnt send a signal to the viscous. on the road it was in death valley and the temp was in the red but then pulled up the m66 no problem just over a half on the gauge I hope its not the ecu.

xf105’s have a bad habit of getting clogged up inbetween the radiators restricting airflow through thus affecting cooling down, get the rad and intercooler out at give them a good clean, as for the fan it will probably be the fan it’s self

Iirc you can see up between the rad and cooler from underneath with a decent torch, the CF models do the same and a good clean with a pressure washer cleans them out nicely, note do not get to close with lance and only spray from directly in front not sideways in the slightest bit as you will fold the cooling fins over, will take some time if you have a/c.

Have CF, a while back started running hotter than normal, I always look for the simple things first, upon testing the thermostat found it to be faulty, problem solved.
Hope this helps :smiley:

robwil:
Have CF, a while back started running hotter than normal, I always look for the simple things first, upon testing the thermostat found it to be faulty, problem solved.
Hope this helps :smiley:

interesting …as the thrmoststes are bullet proof but I dare say there is always one …I will add NEVER RUN a DAF WITH NO THERMOSTATE as you will BOIL UP …Removing it opens up a bypass which prevents proper circulation and causes overheating

norb:

robwil:
Have CF, a while back started running hotter than normal, I always look for the simple things first, upon testing the thermostat found it to be faulty, problem solved.
Hope this helps :smiley:

interesting …as the thrmoststes are bullet proof but I dare say there is always one …I will add NEVER RUN a DAF WITH NO THERMOSTATE as you will BOIL UP …Removing it opens up a bypass which prevents proper circulation and causes overheating

is there not a gauze filter in the water jacket somewhere that gets clogged up and restricts water flow norb?

scotstrucker:

norb:

robwil:
Have CF, a while back started running hotter than normal, I always look for the simple things first, upon testing the thermostat found it to be faulty, problem solved.
Hope this helps :smiley:

interesting …as the thrmoststes are bullet proof but I dare say there is always one …I will add NEVER RUN a DAF WITH NO THERMOSTATE as you will BOIL UP …Removing it opens up a bypass which prevents proper circulation and causes overheating

is there not a gauze filter in the water jacket somewhere that gets clogged up and restricts water flow norb?

Theres two gauze jobbies, one on the oil cooler module with large allen key bung at the top and needs a decent hook to remove it (careful as the other allen key bung is some sort of pressure relief valve) as it caused low oil pressure problems due to oil getting to hot, then Daf changed their minds and wanted them refitted again!
Then theres one the front of the motor which is a real ■■■■■■ to remove and is meant to be done on the Y4 service.

DAVIE,can check the operation of the fan hub

Trickydick:

scotstrucker:

norb:

robwil:
Have CF, a while back started running hotter than normal, I always look for the simple things first, upon testing the thermostat found it to be faulty, problem solved.
Hope this helps :smiley:

interesting …as the thrmoststes are bullet proof but I dare say there is always one …I will add NEVER RUN a DAF WITH NO THERMOSTATE as you will BOIL UP …Removing it opens up a bypass which prevents proper circulation and causes overheating

is there not a gauze filter in the water jacket somewhere that gets clogged up and restricts water flow norb?

Theres two gauze jobbies, one on the oil cooler module with large allen key bung at the top and needs a decent hook to remove it (careful as the other allen key bung is some sort of pressure relief valve) as it caused low oil pressure problems due to oil getting to hot, then Daf changed their minds and wanted them refitted again!
Then theres one the front of the motor which is a real ■■■■■■ to remove and is meant to be done on the Y4 service.

There is a filter in the oil module that should be removed on first xs but that throws up oil pressure issues .Again correct DAF remove it ,fit it ,remove it lol…There isn’t a water filter on uk motors ,I know the states use them ,but not I the uk

There is a filter in the oil module that should be removed on first xs but that throws up oil pressure issues .Again correct DAF remove it ,fit it ,remove it lol…There isn’t a water filter on uk motors ,I know the states use them ,but not I the uk
[/quote]
Have you done any of the gauzes on the front of the MX12 engines? I left Daf just as they started doing them, gutted I was!

Norb if you do facebook its well worth joining the diesel mechanics forum, Paccar are having some serious issues with engines over in the USA some MX13 arent making a couple of hundred kilometres before totally seizing up, some sort of oil pump/pick up issue?
There was another post where all the paccar engined motors had to be disabled so they could not be started as directed by Paccar and another one where they were doing engine swaps, all the seized and none seized ones had to go back to Paccar still sealed up.
Its a good read as their trucks/running gear seem to be in the dark ages but their engines are the same as ours bang up to date, they still reckon drum brakes are the bees knees :grimacing:
Its like going back 20 years over here.

Trickydick:
There is a filter in the oil module that should be removed on first xs but that throws up oil pressure issues .Again correct DAF remove it ,fit it ,remove it lol…There isn’t a water filter on uk motors ,I know the states use them ,but not I the uk

Have you done any of the gauzes on the front of the MX12 engines? I left Daf just as they started doing them, gutted I was!

Norb if you do facebook its well worth joining the diesel mechanics forum, Paccar are having some serious issues with engines over in the USA some MX13 arent making a couple of hundred kilometres before totally seizing up, some sort of oil pump/pick up issue?
There was another post where all the paccar engined motors had to be disabled so they could not be started as directed by Paccar and another one where they were doing engine swaps, all the seized and none seized ones had to go back to Paccar still sealed up.
Its a good read as their trucks/running gear seem to be in the dark ages but their engines are the same as ours bang up to date, they still reckon drum brakes are the bees knees :grimacing:
Its like going back 20 years over here.
[/quote]
I’m in the fortunate position where I don’t do servicing …Though I have never seen a filter and I cant find one on parts rapido …We definitely don’t have the issue the yanks are having ,May be the Mexicans aren’t building the engines very well for the American market ,Trump wont be happy :smiley: :smiley: :smiley: …Ive heard they are behind the times

norb:

Trickydick:

norb:
There is a filter in the oil module that should be removed on first xs but that throws up oil pressure issues .Again correct DAF remove it ,fit it ,remove it lol…There isn’t a water filter on uk motors ,I know the states use them ,but not I the uk

Have you done any of the gauzes on the front of the MX12 engines? I left Daf just as they started doing them, gutted I was!

Norb if you do facebook its well worth joining the diesel mechanics forum, Paccar are having some serious issues with engines over in the USA some MX13 arent making a couple of hundred kilometres before totally seizing up, some sort of oil pump/pick up issue?
There was another post where all the paccar engined motors had to be disabled so they could not be started as directed by Paccar and another one where they were doing engine swaps, all the seized and none seized ones had to go back to Paccar still sealed up.
Its a good read as their trucks/running gear seem to be in the dark ages but their engines are the same as ours bang up to date, they still reckon drum brakes are the bees knees :grimacing:
Its like going back 20 years over here.

I’m in the fortunate position where I don’t do servicing …Though I have never seen a filter and I cant find one on parts rapido …We definitely don’t have the issue the yanks are having ,May be the Mexicans aren’t building the engines very well for the American market ,Trump wont be happy :smiley: :smiley: :smiley: …Ive heard they are behind the times

I will see my mate in the next week or two as hes still there and will ask him to get me one of the front gauzes.
I can remember the arguments we had as we all said theres not one in the front of the engine, then someone worked it out and it was uh oh!
I did have one but threw it away its about 4 inches long and has a large female hex for an allen key either 17 or 19mm.

Amazingly I text mate and he must have been looking at the bulletin as he came straight back with the part numbers!
It screws into the bottom of the water pump housing and part nos are 2110990 which was 18533601
If you find it on rapido can you post up an image as Ive not seen it myself?

Should it even kick in at that low temperature ? Volvos and Scanias are set to somewhere around 110-115 celsius.

Why would a viscous coupling be connected to the ECU?
Viscous couplings use a bi metalic strip fastened to the front of the fan hub that senses the temperature of the air coming out of the radiator matrix.As it expands it allows silicon oil into what is really a fluid flywheel to drive the fan.
The “filter” on the cooling system is a dosing unit that allows the slow escape of DCA (diesel coolant addative ) into the cooling system at a controlled rate to stop electrolosis of the liners due to the coolant becoming acidic.It keeps the ph of the coolant slightly alkaline.It doesnt filter anything.

Bking:
Why would a viscous coupling be connected to the ECU?
Viscous couplings use a bi metalic strip fastened to the front of the fan hub that senses the temperature of the air coming out of the radiator matrix.As it expands it allows silicon oil into what is really a fluid flywheel to drive the fan.
The “filter” on the cooling system is a dosing unit that allows the slow escape of DCA (diesel coolant addative ) into the cooling system at a controlled rate to stop electrolosis of the liners due to the coolant becoming acidic.It keeps the ph of the coolant slightly alkaline.It doesnt filter anything.

I think you will find the viscous fan hub is a std unit that reports its speed back to the engine ecu and the ecu can ask the fan to lock up when needed.
On the daf they went from the std non elec hub to the elec version in approx late 2007 on the CF so assume the XF is the same?
Ive repaired a few of the looms and Iirc there are 4 wires

Never seen a daf fitted with a coolant filter but Im sure I have seen it in the parts book as an option, what I was talking about is coolant gauzes on the MX12 engine of which there are two, one everyone knows about and the second thats very well hidden.

Trickydick:

Bking:
Why would a viscous coupling be connected to the ECU?
Viscous couplings use a bi metalic strip fastened to the front of the fan hub that senses the temperature of the air coming out of the radiator matrix.As it expands it allows silicon oil into what is really a fluid flywheel to drive the fan.
The “filter” on the cooling system is a dosing unit that allows the slow escape of DCA (diesel coolant addative ) into the cooling system at a controlled rate to stop electrolosis of the liners due to the coolant becoming acidic.It keeps the ph of the coolant slightly alkaline.It doesnt filter anything.

I think you will find the viscous fan hub is a std unit that reports its speed back to the engine ecu and the ecu can ask the fan to lock up when needed.
On the daf they went from the std non elec hub to the elec version in approx late 2007 on the CF so assume the XF is the same?
Ive repaired a few of the looms and Iirc there are 4 wires

Never seen a daf fitted with a coolant filter but Im sure I have seen it in the parts book as an option, what I was talking about is coolant gauzes on the MX12 engine of which there are two, one everyone knows about and the second thats very well hidden.