Fuel cooler

twodogs · Sat Oct 03, 2020 12:09 pm

Hi Guys, Has anyone fitted a fuel cooler to a PX3 3.2lt and if so any pics and how you did it...

CatHerder · Wed Oct 07, 2020 4:52 pm

Does it need one?.
I've started monitoring fuel temp this year and haven't seen it hit more than 37C. Do you have some summer data you can share?
Engine performance shouldn't be affected until the fuel temp gets to 75C (but will get very sluggish at 80+C) so I'm not sure how often this scenario will occur.

Iainboyd · Fri Oct 09, 2020 9:25 am

The fuel pump in the tank is a low pressure high volume pump that circulates the fuel through the filter and the mechanical high pressure delivery pump and back to the filter and fuel tank.
It passes through the mechanical fuel pump to not only supply filtered fuel to it but also to cool it. Given that it delivers around 70-90 litres per hour every drop of fuel in the standard 80 litre tank will bet filtered and circulated every hour.
I dont see how even under the most severe conditions the constantly circulating fuel would ever exceed 5 degrees over the ambient road temperature, on say a 45*C day that could reach 70*c on bitumen (at which point the bitumen is melting) but at least 15 degrees lower on dirt. So, like you, I really dont see the need for one.
The worst condition would be a 1/4 full tank and ambient temperatures exceeding 45*C.

CatHerder · Fri Oct 09, 2020 9:49 am

I dont see how even under the most severe conditions the constantly circulating fuel would ever exceed 5 degrees over the ambient road temperature...

Oh, I think it's possible for the fuel to push well into the 70's (C). If you were pressurised to 25000psi then you'd get plenty hot.

The unknown is how much cooling does the fuel system tank and piping provide. We're fortunate that all the hot exhaust stuff is on the other side of the vehicle (exhaust doesn't switch sides), and the cab-tray configuration provides potential for more air circulation underneath vs a wagon. That's why it's unclear to me what the real situation is. If diesel gets hot or has lots of entrapped air, engine performance will suffer so I like this discussion. I am a data person though, so for me I need to measure the issue first to know if there's a problem, and then measure again to know if it gets fixed if a change is made.

twodogs · Fri Oct 09, 2020 11:53 am

OK, I've fitted a PX1 fuel cooler to my PX3 and I'll se how it goes . While I was at Fords earlier with a trans problem the Ford Warranty guy told me to be more worried about the fuel temp if I was towing. It must mean something if he volunteered that info. Apparently they deleted the fuel cooler on the PX1 for what reason???

Iainboyd · Fri Oct 09, 2020 1:23 pm

CatHerder wrote: ↑Fri Oct 09, 2020 9:49 am
I dont see how even under the most severe conditions the constantly circulating fuel would ever exceed 5 degrees over the ambient road temperature...
Oh, I think it's possible for the fuel to push well into the 70's (C). If you were pressurised to 25000psi then you'd get plenty hot.
The unknown is how much cooling does the fuel system tank and piping provide. We're fortunate that all the hot exhaust stuff is on the other side of the vehicle (exhaust doesn't switch sides), and the cab-tray configuration provides potential for more air circulation underneath vs a wagon. That's why it's unclear to me what the real situation is. If diesel gets hot or has lots of entrapped air, engine performance will suffer so I like this discussion. I am a data person though, so for me I need to measure the issue first to know if there's a problem, and then measure again to know if it gets fixed if a change is made.

The highly pressurised fuel -( 25000 psi ) goes into the "common rail" and to the injectors, any excess fuel passes through the relief valve in the FIP is returned into the fuel filter and I agee, the "unknown" is the amount of coooling the pipe system, and the quantity of fuel remaining in the tank provides. It would indeed be interesting to know just how hot the fuel in the common rail gets to. If there was any place to install a cooler that would be the ideal location -- to cool the fuel down before it was injected.
From what data I have in the Ford manual the tank pump only delivers about 20 psi to the 5 micron filter and from there to the FIP from where it is returned, via the top of the fuel filter, back to the fuel tank.
On the Freightliner Argosy B-Double I occassionally drive ( Cummins 15 litre, 6 cylinder ) there is no fuel cooler and the diesel fuel passes through the fuel filters and then through the central ECU to cool it before going to the FIP. It carries 4 off 200 litre alloy fuel tanks.

Fri Oct 09, 2020 10:34 pm

Iainboyd wrote: ↑Fri Oct 09, 2020 1:23 pm
CatHerder wrote: ↑Fri Oct 09, 2020 9:49 am
I dont see how even under the most severe conditions the constantly circulating fuel would ever exceed 5 degrees over the ambient road temperature...
Oh, I think it's possible for the fuel to push well into the 70's (C). If you were pressurised to 25000psi then you'd get plenty hot.
The unknown is how much cooling does the fuel system tank and piping provide. We're fortunate that all the hot exhaust stuff is on the other side of the vehicle (exhaust doesn't switch sides), and the cab-tray configuration provides potential for more air circulation underneath vs a wagon. That's why it's unclear to me what the real situation is. If diesel gets hot or has lots of entrapped air, engine performance will suffer so I like this discussion. I am a data person though, so for me I need to measure the issue first to know if there's a problem, and then measure again to know if it gets fixed if a change is made.
The highly pressurised fuel -( 25000 psi ) goes into the "common rail" and to the injectors, any excess fuel passes through the relief valve in the FIP is returned into the fuel filter and I agee, the "unknown" is the amount of coooling the pipe system, and the quantity of fuel remaining in the tank provides. It would indeed be interesting to know just how hot the fuel in the common rail gets to. If there was any place to install a cooler that would be the ideal location -- to cool the fuel down before it was injected.
From what data I have in the Ford manual the tank pump only delivers about 20 psi to the 5 micron filter and from there to the FIP from where it is returned, via the top of the fuel filter, back to the fuel tank.
On the Freightliner Argosy B-Double I occassionally drive ( Cummins 15 litre, 6 cylinder ) there is no fuel cooler and the diesel fuel passes through the fuel filters and then through the central ECU to cool it before going to the FIP. It carries 4 off 200 litre alloy fuel tanks.

WTF

Iainboyd · Sat Oct 10, 2020 9:03 am

WTF

??

TrueRed · Sat Oct 10, 2020 6:15 pm

Stop start around town for 2 hours on 30c day fuel tank 1/8 full by gauge fuel temp rose to 58c. Filled tank, fuel temp dropped to mid 30s after 5-10 minutes.

Iainboyd · Sun Oct 11, 2020 8:43 am

TrueRed wrote: ↑Sat Oct 10, 2020 6:15 pm Stop start around town for 2 hours on 30c day fuel tank 1/8 full by gauge fuel temp rose to 58c. Filled tank, fuel temp dropped to mid 30s after 5-10 minutes.

If anyone is still interested when I get back from a week of camping at some Darling River station-stays in the north of the state - (Covid-19 R&R) I'll sit down and try to work out exactly how much energy in kilo-joules is needed to heat up a 3/4 full fuel tank , 60 litres, to over 70*C.
My guess is it will be considerable.
I'll work on the parameters of:-

38*Centigrade ambient summer day,
I will assume 50*C reflected heat temperature off the bitumen road surface and
The engine coolant at 89*C and
3/4 full fuel tank with 60 litres of diesel.
Trip duration, 2 hours.

I'll have to fudge the surface cooling factor of the fuel tank surface as zero as most are plastic which is a good insulator and ignore any increase in temperature from the fuel lines.

Mon Oct 12, 2020 2:49 pm

TrueRed wrote: ↑Sat Oct 10, 2020 6:15 pm Stop start around town for 2 hours on 30c day fuel tank 1/8 full by gauge fuel temp rose to 58c. Filled tank, fuel temp dropped to mid 30s after 5-10 minutes.

Did similar driving in same temp with high humidity today.
Highest I saw was 43 but mostly 37 with 120lts of fuel on board.

mark82 · Sat Oct 17, 2020 10:43 am

My ranger went to Limp mode 2 days ago when I try to climb Toowoomba range. No warning light at all. I find the info from the other forum that ranger will be in limp mode and no warning light flashing when fuel temp goes too high( above 85).

I will plug my scanner to monitor the fuel temp when I goto Toowoomba next time, and see if limp mode kicks in again.

Sat Oct 17, 2020 11:26 am

There are many things that can cause limp mode but show nothing.

Sun Oct 18, 2020 8:32 pm

Fuel Temp
Between 75 and 85 is when torque starts to be pulled from the engine, more noticeable between 80 and 85 degrees.
From 85 degrees the engine will not rev past 2000rpm and limits torque across the board to 200nm.

twodogs · Sun Oct 25, 2020 5:38 pm

After I fitted the fuel cooler we just completed a trip up to Tablelands and Ravenshoe with van on .gross weight of 5t. some fairly good hills up there and hot days of about 30 deg. The highest I saw was around 45 deg.FT which I was more than happy with. And fuel consumption was around 13.8 LP 100 .was happy with that as a bloody lot of pulling up that way...

mark82 · Sun Dec 06, 2020 10:55 pm

Went to Toowoomba Twice after last limp mode incident.
Fuel temp max was 47, and no more limp mode have occurred. I have read a old article about common fault of ranger, apparently fuel pump( not the one in the fuel tank) has stuck piston could cause high fuel temp. The fix is ignition off then restart the car.