Ranger Mods

Recently my Redarc Low Coolant Alarm has been giving inconsistent and unaccountable alarms, this occurs on the flat as well as on uphill and downhill slopes. I've checked the coolant levels and the radiator has been full has anyone has similar issues ? I've included a photo of my sensor installation on the Koyorad radiator, its essentially a 3 mm piece of alloy welded to the top of the radiator and tapped 1/8" NPT to take the Redarc sensor, measured with a vernier depth gauge the stainless steel tip of the sensor is a good 14 mm inside the radiator coolant.
As you may recall I used to have a 3 mm dia. stainless steel wire probe in the pressure cap of the expansion tank which worked very well as the Redarc sensor but after several adverse comments I reverted to using the OE Redarc sensor and had it fitted into the Koyorad Radiator.

For the past 6 odd moths its worked very well and only recently has had this intermittent alarm. Any ideas as to what the issue may be ?

By the way the pump in the photo is what I use to extract all the air from the coolant system, I run it from the radiator air vent port to the expansion tank and leave it running until there are no more air bubbles being circulated or drawn out of the radiator.

Can't help you, I use an Engine Guard

If it has only started playing up since you had the radiator out there may be air around the sensor. Loosen the sensor woud bleed any air.

Bala1 wrote: ↑Fri Feb 04, 2022 2:17 pm If it has only started playing up since you had the radiator out there may be air around the sensor. Loosen the sensor woud bleed any air.

Yes, that was the first thing I did, and there was no air - all I got for my troubles was scalding hot coolant spurting out under 20 psi pressure.
Just a thought, my coolant is a 50/50 mixture of Ford OAT concentrate and as per the Ford instructions it's mixed with 50% demineralised water. Could it be that without the "mineral" content the coolant is less likely to carry a small sensing current and so causes the sensor to think that there is no coolant present ?
I'm grasping for answers here

RossPat wrote: ↑Fri Feb 04, 2022 12:38 pm Can't help you, I use an Engine Guard

It's the same beast under a different brand. I looked at the Engine Guard supplied by Berrima Diesel and it works in exactly the same way, the ICU possibly even comes out of the same Korean or Chinese factory. There was no difference in price to speak of either.
I only went with the Redarc low coolant sensor as that's the brand I've stuck by and its paid off. When a few too many corrugations in WA destroyed my Redarc 1000 watt inverter, ( it had an ominous "death rattle" inside it ) and despite it being 18 months out of warranty they exchanged it for a brand new one free of charge and with an extended 2 year warranty. It does pay to establish some relationships.

My Engine Guard is external, I don't want anything that requires entering water.

I will ask again,

Did it only start playing up since you had the radiator out?

Being you mention relationships and warranties, have you contacted the manufacturer for support?

saeb wrote: ↑Sat Feb 05, 2022 6:24 pm Being you mention relationships and warranties, have you contacted the manufacturer for support?

Good morning Stuart,

Yes, they did supply a new sensor probe at a discounted cost and I have since connected an earth cable from the radiator frame to the car chassis to ensure a good earth conductivity as well as replacing the entire connecting cable from the sensor to the alarm unit - just in case there was a break in the wire or poor connections at either end.

They, (Redarc), have asked that I take it to their nominated local auto electrician to check it out for them but who unfortunately is unable to assist me at this time due to him being tested positive to Covid 19 and he's in self isolation until the 14th of this month -- before he can be re-tested.
Hopefully he will then return a negative result and can return to work.
I guess I'll just need to be patient and wait until hes fully recovered and has worked his way through his back-log of outstanding work before he can fit me in for an inspection.

Thank you for your interest.

Bala1 wrote: ↑Sat Feb 05, 2022 6:12 pm I will ask again,

Did it only start playing up since you had the radiator out?

No, the first occasion the alarm went off was in August 2021 on the Tanami Road the morning after we camped up at the Tilmouth Roadhouse. It's a flat bitumen section from the roadhouse to Alice Springs and for no reason it went off, I pulled over and unscrewed the sensor and all that came out was coolant - no air at all.

The previous two days we had driven down the Tanami Road from Halls Creek to the Tilmouth Roadhouse via the Wolfe Creek Crater , in all 1685 kilometres of in places very badly corrugated clay topped track. The final 235 kilometres from the indigenous community at Yeundumu to Alice Springs is bitumen so I was surprised that it sounded on this flat and smooth surface rather than the corrugated tracks we had driven on the previous two days.

Since then it has gone off at odd times, on the flat, up and down hill and there have been no signs of there being any coolant loss and inspections I carried out by loosening the sensor there has been no air locks in the radiator. Its very odd.
I only removed the radiator because the people who installed it snapped off the radiator fan cowl clips because they didn't allow for it being 6 mm wider that the OE unit.

RossPat wrote: ↑Sat Feb 05, 2022 11:22 am My Engine Guard is external, I don't want anything that requires entering water.

That's interesting Ross, the "Engine Guard" that Berrima Diesel sent to me online had a probe to sense the coolant . The "kit" included a short machined alloy section to go into the top hose - this housed the sensor.

I mine has the wires exiting the left hand side
It mounts on a small ledge on the right of the steering and the wire fits neatly
https://engineguard.com.au/product/engi ... ensor-kit/

RossPat wrote: ↑Sun Feb 06, 2022 11:43 am 20211219_104622.jpg

Interesting, if there is no probe with this unit into the coolant how does it sense a loss of fluid ?

Many years ago when I was consulting I hired a magnetic water flow meter to determine how much water was being lost on a commercial air conditioning system through various leaks but that was a large unit so how does this work ?

It doesn't go into coolant, as I said previously I don't want to go into water.
It bolts onto the cylinder head near the front
My car runs from 88 to 92deg
That is 80deg externally
My guard is set for an alarm @ 90 which in reality is around 100, well and truly safe

RossPat wrote: ↑Sun Feb 06, 2022 2:14 pm It doesn't go into coolant, as I said previously I don't want to go into water.
It bolts onto the cylinder head near the front
My car runs from 88 to 92deg
That is 80deg externally
My guard is set for an alarm @ 90 which in reality is around 100, well and truly safe

Okay, but from my automotive engineering experience simply sensing temperatures seldom relates to the coolant capacity. Mine engine also runs at 88*C but will on long hill climbs rise to 95*C - you can still get these range of readings even if there is no coolant flowing ( due to a leak ) so be aware of that and please be cautious.
The biggest hurdle to fitting a coolant probe with the OE radiator is the crappy plastic header I accept that and as you can recall I even went as far as fitting my original in the header tank can. It worked but there could have been some "over pressure venting" issues so I changed the location of the probe to a tapping on the alloy header of the Koyorad radiator.

I think I've found the cause of the issue.
When the Koyorad radiator was originally installed the "mechanics" did two stupid things, one was they never allowed for the extra width of the Koyorad and broke the clips off the fan shroud by trying to force it onto the side bracket clips and ended up using fabric duct tape to hold it into position instead of ovalizing the top mounting holes in the plastic side brackets so that the brackets sat flush with the rear face of the Koyorad.
This I've done with a second hand fan shroud and second hand side brackets and the shroud clips slotted into the side brackets perfectly.

Secondly.
For some unknown reason on the plastic radiator header tank they cut back the spud that is part of the 6 mm air vent line connection to the tank. Just why they did this I do not know as they reused the elbow Ford fitting off the plastic vent line. The result of this is however that the vent line does not correctly seal - the elbow fitting has two grey coloured tabs that when pressed in release the line but the line must lock into the rear of the fitting to become correctly sealed.
For some time this seems to have sealed but maybe due to my work on replacing the radiator brackets its no longer sealing.

I came by this as before I changed the side brackets I noticed that there was a level of coolant inside a small internal compartment inside the header tank that the vent line connects to and for some time - since the alarm has been playing up in fact - this small compartment fluid was well above the main container coolant level and this has no longer been the case.

I'm collecting a brand new header tank on Monday from the local Ford dealership and once its fitted I'll let the forum and you Ross and Stuart know if this is/was the cause of the alarm going off due to air bubbles and is the solution but it again confirms my belief that 90% of so called mechanics these days are just grease monkeys and are never to be trusted on your vehicle to do a job properly.

In any case I will take the existing tank back to show them and to ask just why they cut the spud off.

If you're a mechanical engineer why didnt you fit your own radiator initially, to avoid alleged grease monkeys?

Lincolnland wrote: ↑Sat Feb 26, 2022 5:12 pm If you're a mechanical engineer why didnt you fit your own radiator initially, to avoid alleged grease monkeys?

I should have expected this sort of comment from you but the answer is easy, 13/02/2017 a nurse drove head on into the car I was driving putting me into hospital for a tad under 4 months with a shattered spine, after the operation to replace all the disc pads and insert three titanium rods to hold it all together I grew 1.5 cm and a deep dislike of air bags,
in total :-
17 rib fractures
L5 - S1 discs replaced with a synthetic cement
Compound fractures to both knees
Compound fractures to both ankles.
Sternum split in 3 places.
Broken right arm humerus bone
Broken left leg tibia bone
4 teeth dislodged out of the upper jaw

The problem has been fixed !!!!
As I suspected the radiator vent line wasn't sealing on the spigot that had been cut back, as I said, just why this was cut is totally beyond me.
I attach photos of the vent line and the old tank with the spigot, on close inspection it would appear that some sort of sealant had been put on the spigot to cause it to seal.
This is the first time since I replace the radiator fan cowl and the side brackets that the vent line chamber in the header tank has been filled with coolant - a sure sign that there is no air in the top of the radiator and a run up the local hills produced no alarms so this man is once again a happy one, even if it did cost me $145 for a new header tank and OE vent line so I could use the press-on connections from it simply because I suspect that the old connection would have been ruined internally with what appeared to be some sort of silicon sealant .

Okay, I'm just clearing up old questions that I have asked.

I have FINALLY found the cause and it had nothing to do with the radiator.

There is a 10mm OD hose that goes from the top of the thermostat housing to the header tank. Inside the plastic spud on the thermostat housing is cast a brass ferule which in turn has a 1.5mm orifice.
This orifice is to allow the cylinder block to vent and air or steam back to the header tank - the coolant system highest point.
On my engine this had become blocked by a small grain of what appears to be casting sand. I had purchased a new complete thermostat housing - and I surgically dismantled the OE unit. I only found the problem blocked orifice when I stripped down the top end of the motor having been told the head gasket had blown - it hadnt !!!
So, be aware, if the 1.5mm orifice is opened up too much by-pass will occur preventing the thermostat from correctly modulating the coolant temperature, if its blocked or paertially closed the block cannot correctly vent and boom, you have an overheated engine block. When it occured on mine it "dragged" two pistons ( 2 & 3 ) and in doing so badly scoring the lower portion of their bores, a new "short motor" is now on order.
The engine runs fine apart from a ticking sound caused by the two offending pistons but I can live with that in the short term. Its louder on load and is almost inaudible if the engine is just rolling.
The compression rates have been tested and are good the injectors have been serviced and checked and the glow plugs tested, and the Redarc coolant sensor in the Koyorad now works with the radiator now full for the first time since it was installed.