Coolant flow path?

[dpd]

Hi all, a technical question about coolant path on the L300.
This is for the purpose of WVO system install, but I think it is of general interest too.

I'm wondering about the direction of coolant flow in the hoses coming from the small front radiator. From that little radiator, one goes to the engine block, on the passenger side on a big banjo bolt. The other goes to a metal pipe that winds around the engine to the driver's side, maybe to the front heater? This is how it appears anyway!

Is the coolant coming OUT of the engine block here and up front, or is it coming from the little front radiator, TO the engine? I want to know which line is hotter...

Thanks!

[FalcoColumbarius]

http://www.delica.ca/forum/l-300-coolin ... -7336.html

[dpd]

Thanks! I have studied this already and it's not enough to answer my question. Several diagrams point to the 'heater hose' connection that I have seen. But either I am missing something in the doc, or have too sketchy of an understanding of the engine (doubtless).

What confuses me in the manual, is that the engine has 2 main ports for coolant. One is the heater port, the other is the 'outlet'. Intuitively it seems like the 'heater' connection would be taking coolant OUT of the engine, to the heater, and that's what makes the heater...have heat. On the other hand, the words 'outlet connection' imply that coolant is flowing out of THAT one.

So... which direction is the coolant on the 'heater' connection going in? I still can't figure it out.

[FalcoColumbarius]

Hmm.... Okay, at a guess based on what they taught me in skool (very traumatising I might add): Heat rises. If this is the case then I would presume that the hot water would come out of the hot engine at the top of the rad and cooled down as it is drawn through the radiator by the water pump, then fed back into the engine. So.... I am about to make a presumptuous leap and assume that you are driving an L300 Delica with a 4D56T engine in it. If this is the case then it stands to reason that you have a duel heater system, one heating the cockpit and one heating the cabin (front & back). That means you should have 10.2 litres of coolant in your system because it will be feeding the two heaters; ergo there must be access to those two heaters for the water to go. Considering that everything so far is operating on a to and fro basis ~ then I would imagine that both heater systems are going to have two hoses bringing to and taking from the respective heater.

How are we doing so far? One thing I ought to remind you, DPD, I am a painter. The diesel mechanic façade is generated by an active interest in my wagon. Here is what I have been referring to:

• http://www.delica.ca/manuals/L-300%20Ma ... Manual.pdf (11A-6-1)
• The Cooling System link that I posted earlier.
• http://auto.howstuffworks.com/cooling-system8.htm

Falco.

[dpd]

Thanks Falco. I have a 4d56 (no T) and no rear heater system, otherwise what you say fits. I know where the 2 hoses for the front heater are... and I suppose I can figure out which hose is carrying hotter water, by starting up the van and touching both to see which gets hotter first :) I know a few people here are curious about which hose is which so I'll post the result.

It doesn't make TOO much difference for the average WVO install, because the coolant ports on hotfoxes and heated fuel filters tend to be bidirectional. But in my case, I have inserted a brass T for a temperature sensor, and I'd rather get the temp as it's GOING TO the heated fuel filter and hotfox. On -30 days, the return line after all that heating might take a looooong time to get up to operating temp, even though the fuel in the TurboFyner filter is already warm. Driving on WVO in Edmonton this might make a serious difference in switchover times. There's no point gauging the coolant temp AFTER it has gone through all the WVO appliances, heater, radiator etc... it might never show the coolant temp going INTO the appliances, know what I mean? It might not make so much of a difference to WVO systems in more moderate climates.

[FalcoColumbarius]

I'm sorry DPD, I assumed you were driving a Delica. What kind of L300 are you driving? Is this a JDM model? So you have a 4D56 without a turbocharger?

Cheers!

Falco.

[dpd]

OK full story :) I guess I should have started with this!

I have a Delica, on L300 chassis. Same trim, 4WD. But the model variant is a P25V, work van edition: no rear heater or ventilation, no stock audio except the 4 inch speakers in the front, manual trans. It is a factory camper conversion with full Reimo pop top w/bed, fridge, stove, sink, convertible back seat with table, similar to a rigged out westfalia. 4D56 engine with no turbo, but the power and economy are still decent.

So I think the only difference in the cooling system, from a p25w/p35w is that the hoses at the heater connection don't split off to a rear heater. Apart from that, the drivetrain and engine are identical to a typical Delica, as far as I know.

I suppose I could also just temporarily stick a section of clear hose in the coolant path and that would tell me once and for all which way it's going!

[FalcoColumbarius]

Wow. A P25V ~ that is rare. I have some reference to it in my owner's manual but I would have to dig as up to now I have been looking for W info. Out of curiosity, do you have the same size radiator as a W designation L300? I am just thinking that without the extra 1.4 litres of coolant travelling the extra cooling distance, maybe the rad would be bigger?

[dpd]

I think it's the same. I'm only going by pics of other peoples' engine compartments, but just about everything is identical.

[after oil]

off topic: do you have photos posted of your reimo?

[dpd]

These photos are as-of-buying it 3 years ago. Since then I have made tons of improvements, including laminate floors and custom curtains. But no recent photos unfortunately! It sleeps 5 comfortably, 2 up and 3 down.

Notice the webasto air heater.... aw yeah!

http://www.fwalive.ualberta.ca/~dpd/delica/

[mararmeisto]

These photos are as-of-buying it 3 years ago. Since then I have made tons of improvements, including laminate floors and custom curtains. But no recent photos unfortunately! It sleeps 5 comfortably, 2 up and 3 down.

Notice the webasto air heater.... aw yeah!

http://www.fwalive.ualberta.ca/~dpd/delica/

Thread hijack - very cool. Could you post a thread with new pictures of your mods? There aren't too many of these Reimo-vans out there.

[after oil]

i remember those photos from when the deli was for sale i think. i know for sure i have seen those very photos. i check the auctions all the time for reimos!

[dpd]

I need to clean it up from being my toolshed, then I'll post pics. I really like this camper, when the wvo is finally working it will be the ultimate vehicle!

[dpd]

For those who care... I did a very informal test. Started up the van, put the throttle lock on, and held on to both hoses. The 'heater' hose coming out of the block got warm quite a bit faster than the other. So if you're looking for a place for a temperature probe, and to take the most heat out to a WVO component, then that's the one to use. As my WVO pickup and turbofyner don't care which port is which, it was mostly just to know where to put the sensor to get the most accurate coolant temperature out of the block.