Technical Heater core loop always open on 2002 Ducato 2.8JTD (x230)

[TimMat]

Hi there,

I'm a newbie and trying to get my new-to-me Hymer Camp Swing 644G ready for exploring Lapland this winter. I've purchased a Webasto clone diesel pre start heater and am not sure where to make the cut to plumb it into the heater core to engine block loop. Could someone please advise if this is an 'always open' loop? I'd like to plumb it in near the firewall if possible, for ease of installation and as I plan to use it as a backup parking heater. It does seem to be an open loop (at least judging by touch from startup), but I'm confused as to why both the feed and return pass through the thermo valve housing? Any advice would be much appreciated!

 

[bugsymike]

Hi there,

I'm a newbie and trying to get my new-to-me Hymer Camp Swing 644G ready for exploring Lapland this winter. I've purchased a Webasto clone diesel pre start heater and am not sure where to make the cut to plumb it into the heater core to engine block loop. Could someone please advise if this is an 'always open' loop? I'd like to plumb it in near the firewall if possible, for ease of installation and as I plan to use it as a backup parking heater. It does seem to be an open loop (at least judging by touch from startup), but I'm confused as to why both the feed and return pass through the thermo valve housing? Any advice would be much appreciated!

Double check in case I am wrong , but I think you will find on most modern vehicle the coolant from the engine flows all around the system including the heater matrix/radiator all of the time, with cabin temperature controlled by air flaps.
Two reasons for this, one manufacturers can get away with smaller main radiator as the heater radiator acts as extra capacity and two is that a common source of water leak used to be the control valve/tap that managed the flow around the heater in the old days.
The only thing that is confusing me is you mention both heater pipes pass through the "thermo valve coupling", unless your vehicle has a different set up as maybe due to being sold in colder climate than ours over here.
Perhaps @Communicator can advise?

 

[TimMat]

Double check in case I am wrong , but I think you will find on most modern vehicle the coolant from the engine flows all around the system including the heater matrix/radiator all of the time, with cabin temperature controlled by air flaps.
Two reasons for this, one manufacturers can get away with smaller main radiator as the heater radiator acts as extra capacity and two is that a common source of water leak used to be the control valve/tap that managed the flow around the heater in the old days.
The only thing that is confusing me is you mention both heater pipes pass through the "thermo valve coupling", unless your vehicle has a different set up as maybe due to being sold in colder climate than ours over here.
Perhaps @Communicator can advise?

Thanks for the response. Mine definitely has a thermo valve and the radiator loop does not open till it warms up, and yes, the heater core loop also passes through it - which is what I'm confused about also. It could be a cold climate thing as you suggested, but I would not have thought that the heater loop would have a valve.. so why does the loop go through the thermo housing?!?. Because it's a Hymer, I'm not able to pull up the OEM parts for my VIN, so at odds here. Chat GPT also seems equally confused...

 

[bugsymike]

Thanks for the response. Mine definitely has a thermo valve and the radiator loop does not open till it warms up, and yes, the heater core loop also passes through it - which is what I'm confused about also. It could be a cold climate thing as you suggested, but I would not have thought that the heater loop would have a valve.. so why does the loop go through the thermo housing?!?. Because it's a Hymer, I'm not able to pull up the OEM parts for my VIN, so at odds here. Chat GPT also seems equally confused...

When you say Thermo are you referring to what I would call a thermostat, something normal fitting on most engines. If that is the case then often the plumbing is designed so as engine warms up from cold if you have your hand on the heater pipes going into the bulkhead from the engine you will notice when the thermostat opens and those pipes get hot. You may get more information from that and earlier 2.8 Sofim engines online. I would suggest Iveco Daily, but they are rear wheel drive and the plumbing is slightly different.

 

[TimMat]

When you say Thermo are you referring to what I would call a thermostat, something normal fitting on most engines. If that is the case then often the plumbing is designed so as engine warms up from cold if you have your hand on the heater pipes going into the bulkhead from the engine you will notice when the thermostat opens and those pipes get hot. You may get more information from that and earlier 2.8 Sofim engines online. I would suggest Iveco Daily, but they are rear wheel drive and the plumbing is slightly different.

Yes, sorry I'm Australian and we shorten everything - I'm referring to a thermostatic valve, as per your description. I know there is one to the radiator loop (like nearly all modern vehicles), just not sure if there is a valve on the heater coil loop..

 

[bugsymike]

Yes, sorry I'm Australian and we shorten everything - I'm referring to a thermostatic valve, as per your description. I know there is one to the radiator loop (like nearly all modern vehicles), just not sure if there is a valve on the heater coil loop..

To the best of my knowledge at least in UK Ducatos there is no other valve, my concern was if something was used for the extreme conditions where you are.

 

[Communicator]

I have been and will be busy trying to keep pace with removing autumn leaves and beech mast, when the weather allows." Rain stopped play."

Given the invitation and my curiosity I have been looking into this but as I have not had cause to remove either thermostat or heater, my input is restricted to what I can see, and what I can glean from eLearn.

I have no problem with both heater hoses connecting to the thermostat housing, provided that the thermostat sits between the two connection points.

eLearn for the x244 does mention a tap on the heater assembly, but I translate tap as meaning valve. This suggests that temperature is partly controlled by engine coolant flow rate through the heater matrix. However another part illustrated in eLearn is an air bleed connection at the heater, for bleeding the cooling system/heater. This appears to be inside the cab, and goes to a bleed valve situated where. There is no apparent bleed point on the heater hoses in the engine bay. I would question the wisdom of having an inaccessible bleed valve, if it exists.

Edit
@TimMat, I will add that my vehicle is a 2006 x244 2.8jtd.

 

[bugsymike]

I have been and will be busy trying to keep pace with removing autumn leaves and beech mast, when the weather allows." Rain stopped play."

Given the invitation and my curiosity I have been looking into this but as I have not had cause to remove either thermostat or heater, my input is restricted to what I can see, and what I can glean from eLearn.

I have no problem with both heater hoses connecting to the thermostat housing, provided that the thermostat sits between the two connection points.

eLearn for the x244 does mention a tap on the heater assembly, but I translate tap as meaning valve. This suggests that temperature is partly controlled by engine coolant flow rate through the heater matrix. However another part illustrated in eLearn is an air bleed connection at the heater, for bleeding the cooling system/heater. This appears to be inside the cab, and goes to a bleed valve situated where. There is no apparent bleed point on the heater hoses in the engine bay. I would question the wisdom of having an inaccessible bleed valve, if it exists.

Edit
@TimMat, I will add that my vehicle is a 2006 x244 2.8jtd.

I need to prune my Magnolia but I am having trouble with hip and leg pain at present. Given last year I fell off the ladder doing it I am being cautious.
I think OPs concern is if there is any kind of shut off valve rather rather than an air bleeder as he wants to fit an aftermarket heating system for where he lives, presumably remote controlled from indoors, so when he goes to the vehicle it is lovely and warm and starts instantly.
Less of a problem where I live as any frost on the winscreen I simply wait for the sun to reach and it soon goes away.
From memory it was around six years ago that there was even enough snow in my garden for my daughters to do "snow angels".

 

[Communicator]

Below is what I found in eLearn. I am curious as to where item 5b terminates. The highlighting is mine.

The complete section may be viewed here, but it does relate to the x244 model.

"1. Remove the bands (1a) and (1b) retaining the heater radiator supply and return pipes.2. Undo the bolts fixing the tap.- Open the tap control cable retaining spring.3. Disconnect the tap control cable and remove it.4. Disconnect the heater radiator supply and return pipes and remove the tap.5. Remove the band (5a) and remove the flexible pipe complete with connector for bleeding the cooling system (5b).

 

[bugsymike]

Below is what I found in eLearn. I am curious as to where item 5b terminates. The highlighting is mine.

The complete section may be viewed here, but it does relate to the x244 model.

"1. Remove the bands (1a) and (1b) retaining the heater radiator supply and return pipes.2. Undo the bolts fixing the tap.- Open the tap control cable retaining spring.3. Disconnect the tap control cable and remove it.4. Disconnect the heater radiator supply and return pipes and remove the tap.5. Remove the band (5a) and remove the flexible pipe complete with connector for bleeding the cooling system (5b).
View attachment 475906

So from the sound of that, then it does have a control valve at the heater matrix, this may be a problem then for the OP as he wants to fit that auxillary heater.
Unless he thinks it viable to set that valve permanently open so his auxilary heater will be able to circulate the warm water through the whole system.
Is that valve part in picture on the heater unit inside tha cabin?

 

[Communicator]

So from the sound of that, then it does have a control valve at the heater matrix, this may be a problem then for the OP as he wants to fit that auxillary heater.
Unless he thinks it viable to set that valve permanently open so his auxilary heater will be able to circulate the warm water through the whole system.
Is that valve part in picture on the heater unit inside tha cabin?

Yes. All that I can see in my engine bay is the upper (heater end) of the two rubber hoses. A view of the thermostat housing end would require some dismantling or use of a borescope.

 

[TimMat]

Thank you for this gents. It does however make me even more confused . I did I test today starting the engine from cold and using a laser thermometer. Both the lines from the engine block to the thermostat, and, from the thermostat to the firewall got warm at the same rate and consistently had the same temperature. This would imply that it is infact an open circuit. I'm guessing (hoping) that it is different on the x230?

 

[bugsymike]

Thank you for this gents. It does however make me even more confused . I did I test today starting the engine from cold and using a laser thermometer. Both the lines from the engine block to the thermostat, and, from the thermostat to the firewall got warm at the same rate and consistently had the same temperature. This would imply that it is infact an open circuit. I'm guessing (hoping) that it is different on the x230?

Just to confuse you further Does your vehicle normally warm up quickly and reach the middle of the temp gauge when during normal road use? If not it can mean the engine thermostat is stuck open which can account for pipes warming up equally, but slowly.
What I generally do is start an engine from cold, set the accelerator to around 1500 rpm to warm up quickly for the test using a bar from the seat to the accelerator pedal, then carefully check all the hoses, generally the bottom hose will gradually warm up whilst the top hose stays cold until the thermostat opens and then the top hose and bottom hose plus any others including heater ones should all be equally hot.
I find if the temp gauge reads in the middle the it should be approx. 90 degrees Centigrade, at which point you can only bear your hand on the hose for a short while.
Obviously where you are the climate makes a big difference, but generally engines run most efficiently with temp. gauge in the middle, 90 Degrees Centigrade approx. although I am aware that 2.8 Sofim engines usually run around 80 Degrees Centigrade with a standard thermostat fitted.
If you are not worried about losing the existing coolant , you can test the water flow with a cold engine and switched off by running a water/garden hose into the system.
Note don't make a tight seal as often water masins pressure is far greater than the approx. 15 psi of the coolant system
Another though re your kit, why don't you ask the supplier as they should be the best people to advise you?

 

[TimMat]

Just to confuse you further Does your vehicle normally warm up quickly and reach the middle of the temp gauge when during normal road use? If not it can mean the engine thermostat is stuck open which can account for pipes warming up equally, but slowly.
What I generally do is start an engine from cold, set the accelerator to around 1500 rpm to warm up quickly for the test using a bar from the seat to the accelerator pedal, then carefully check all the hoses, generally the bottom hose will gradually warm up whilst the top hose stays cold until the thermostat opens and then the top hose and bottom hose plus any others including heater ones should all be equally hot.
I find if the temp gauge reads in the middle the it should be approx. 90 degrees Centigrade, at which point you can only bear your hand on the hose for a short while.
Obviously where you are the climate makes a big difference, but generally engines run most efficiently with temp. gauge in the middle, 90 Degrees Centigrade approx. although I am aware that 2.8 Sofim engines usually run around 80 Degrees Centigrade with a standard thermostat fitted.
If you are not worried about losing the existing coolant , you can test the water flow with a cold engine and switched off by running a water/garden hose into the system.
Note don't make a tight seal as often water masins pressure is far greater than the approx. 15 psi of the coolant system
Another though re your kit, why don't you ask the supplier as they should be the best people to advise you?

Thanks mate... It does take a while to warm up here, at least compared to what I'm used to in Australia, but I'm told that's just the antifreeze I did have a moment of panic regarding the thermostat being stuck when I discovered the bottom radiator hose warming up, but as per your description, the top one remained cold till at temp... So from what I understand, that means it's working. You learn something every day!
Unfortunately, all the money I've spent so far getting this bugger cleaned up has left my budget somewhat strained, so I opted for a Chinese clone - not much by way of customer service. I did however find some references to the line always being open in Webasto's install notes for the x230 last night...
At this point I'm 95% certain it's always open, so time to cut it and see. Worst comes to worse and it doesn't work, I'll just need to make another cut in between the thermostat and engine block outlet and tee it in parralel (instead of in series like I'm doing now), which is the prescribed method for vehicles with mixing valves anyway...


Appreciate your response!

 

[jackwhoo]

Post 10
Fit aux heater you want but make sure to have cab lever/knob on full hot when using aux heater-that will put heater matrix loop open.

 

[bugsymike]

Re the antifreeze comments affecting temp it is not something I have noted, I always run 50% antifreeze, what % do you guys run where you are now?
I recall as an apprentice we had a customer whose engine froze and required a new cylinder block due to his argument that no antifreeze needed in Sunny Devon. On completeing the job he was asked if he would have antifreeze now in his new engine. He replied "NO ! Lightening doesn't strike twice". So no helping some people.

 

[jackwhoo]

Re the antifreeze comments affecting temp it is not something I have noted, I always run 50% antifreeze, what % do you guys run where you are now?
I recall as an apprentice we had a customer whose engine froze and required a new cylinder block due to his argument that no antifreeze needed in Sunny Devon. On completeing the job he was asked if he would have antifreeze now in his new engine. He replied "NO ! Lightening doesn't strike twice". So no helping some people.

Im with you Mike using correct coolant does not make the engine run cooler...however it does increase the boiling point of the coolant liquid and decrease the freezing point