Water temp spiking on hills...what to look for

[weeds]

Currently touring NSW and the temp gauge is wanting to rise about 105 degrees on the hills and sits between 90 and 95 on the flat at 100km/hr

First time towing the camper trailer which weighs in at 1200kg, unloaded around the city it seems to sit around 90 degrees

New radiator fitted jan 2011

Low water alarm is not going off

Oh and I have a mechanical temp gauge which has a nice spread 40-120 degrees starting at 7 through to 5 on the face

What should I be checking when I get into armidale????

Backing off on the hills seems to be working and we are in no rush.....

[muddymech]

Viscous fan. Be quick easy place to start.

[Distortion]

My Disco had a similar issue

at 110 fully loaded I would see the temp gauge climb back off to 80/90kph and temp would drop back to normal

Could never get it to happen with no load in/behind the car. The way it was put to me was the radiator was likely partially blocked and the back preasure combine with the high pump rpm was causing cavitation and once that started pumping efficency dropped dramatically. Back off the rpm and cavitation would stop and it would be moving enough coolant again to keep it cool.

Fast forward a couple of months got the radiator flushed and rodded out(40% Blocked) and on another long trip even more heavily loaded there was no sign of the previous issue.

[wrinklearthur]

'Fred' (D1 300TDi man) is doing the same, with the exact same symptoms.
Changed the viscous fan hub over with a second hand one and that was a bit of a improvement.
Still noticed the temperature rising when we went up through Black Charlies Opening on the way to the East Coast last weekend, so the radiator will be removed next to get rodded out.

.

[weeds]

Viscous fan. Be quick easy place to start.

How does one check the viscous fan??

[weeds]

I'm wondering if I need to remove a land rover badge from the grill...

Gave her the once over, no water leaks and level has not moved

I do have an oil leak on the side of the motor....vac pump maybe? Noticed a film of oil on the camper trailer.

Will check viscous fan once armed with the knowledge

[Blknight.aus]

thats not dangerous depending on the cooling mix your using.

the boiling point of plain water at 14psig is 119 degrees

the boiling point of most coolant mixes at atmospheric pressure is about 104-110 (varies with brand and concentrate)

I would be starting with checking out if theres any airflow blockages to the radiator ( I see about 3 a year with the gap between the condensor and the radiator full of mud) the Fan VC, the operation of the thermostat (if its only partially opening you wont get full coolant flow through the radiator), the condition of the radiator (if its restricting flow again you wont get full flow through the radiator)


If fault finding shows it to be a blocked radiator, Dump the coolant, flush the whole cooling system with tap water as best you can, put in a cooling system cleaning/flushing agent and then take it into a shop to have the radiator Rodded/recored as appropriate and tell them that while they have it you would like a new thermostat installed and a pressure flush or back wash (essentially the same thing but it depends on where/who taught the bloke) as you have a cleaning agent in there at the moment (be sure to provide them with the bottle for WHS reasons) Make sure that you have all the details for the vehicle including the type (ethyl-glycol, OAT, HOAT, soluable oil) of coolant that you want to have put into the system.

A word of caution.

If the radiator cores are blocked there is a VERY high chance that the cores of the heater matrix are in the same condition as the radiator. If the bloke doing the rodding complains that they are rotten and this is a sod of a job and damnable landrover parts etc etc you would be wise to have a short section of bypass hose made up to deal with the heater matrix failing.


the quick check for the VC is with the engine cold try to stop it with a bit of cardboard after the engines been idling for about 30 seconds, it should stop quickly, then repeating the test with the engine warm it should chew up the cardboard. You should also check the security of the hub on the drive spindle, if its got any rock in it its US.

[weeds]

A bit of a search tells me I should be able to push the fan around by hand it it should stop pretty much as soon as I take pressure off.....all good

Radiator is clean, condenser has a couple of bugs other than that it looks good as well

Will see how it behaves tomorrow

[weeds]

Oh heater matrix is already bypassed

[Blknight.aus]

A bit of a search tells me I should be able to push the fan around by hand it it should stop pretty much as soon as I take pressure off.....all good



Ummm, not always....

when the fans been sitting the oil pools and fills just one portion of the impeller/turbine drive section giving enough grip to get the initial air flow on start up (picture the vehicle shut down hot facing into a slight breeze, it would only take a minute or 2 for the radiator to cool down and then for the VC to cool down as well giving no drive to the fan on a hot start up)

[wrinklearthur]

I might buy a new viscous fan hub, then I have a old one as a spare.
.

[uninformed]

ok so we are not talking a 20-30c temp change, just 10c when working hard, towing, up hill.....whats to say this isnt normal??

Im pretty confident my truck is in good working order. I did 2 runs to toowoomba the last few weeks. It sits on about 85c and when going up "the Range" it would get to 92c, no load

maybe we are just use to the OEM LR gauge, that is painted on :eek:

[weeds]

105degrees and climbing up cunningham gap.

I'm not overly worried, just never seen it move around like this.

[pop058]

Bigass driving lights blocking air flow ???

[PhilipA]

You wouldn't by any chance have some great big spotlights and /or a winch in front of the grille?
Regards Philip A

[rick130]

Oh heater matrix is already bypassed

IME you need the heater there to give you that little extra cooling capacity, the coolant flows through it all the time, there isn't a valve which turns the flow on and off, only a flap which directs air through the core and into the cabin.
When I by-passed mine it ran a few degrees warmer straight away.

[rick130]

Bigass driving lights blocking air flow ???


You wouldn't by any chance have some great big spotlights and /or a winch in front of the grille?
Regards Philip A


Doesn't seem to make much difference fitted or removed on 300Tdi Deefer.

The air con condenser on the other hand.....

[justinc]

Kelvin,

the rads in these are too small anyway, so anything approaching 20% blockage will cause these symptoms when working hard, even in this cool climate.

JC

[rick130]

Kelvin, my first thought is the viscous clutch too.

I know years ago another Aussie on the old LRE board had a problem with his 300Tdi Deefer o/heating on hills @ 100km/h, someone suggested the fan clutch and I said no way, ram air should be sufficient at that speed.

Guess what, it was the fan clutch.

Defenders have shocking air flow through the engine bay.

If it's original and your upwards of 250,000km now, it might be an idea to replace.
I think I'm on my second or third, I tend to replace them on age as you can't service them like a Nissota.

[rick130]

Kelvin,

the rads in these are too small anyway, so anything approaching 20% blockage will cause these symptoms when working hard, even in this cool climate.

JC

It's surprising how much crud I blew out of the fins two months ago and it looked clean from the front.

Again, the condenser doesn't help here either.

[wrinklearthur]

IME you need the heater there to give you that little extra cooling capacity, the coolant flows through it all the time, there isn't a valve which turns the flow on and off, only a flap which directs air through the core and into the cabin.
When I by-passed mine it ran a few degrees warmer straight away.

Bingo! The matrix must be blocked in 'Fred' as well, as there is only a very moderate heat coming out in comparison with the heater's in our other two 300 TDi's.

Thanks for that.

It makes sense, as the PO of 'Fred" had lots of overheating problems and rubbish from his blown head gasket must got into the coolant and deposited in all of those places.

Didn't some of the Falcons have a three way tap to bypass their heater when the heater wasn't required?
.

[weeds]

Thanks guys.....

Yep two driving lights and a winch

340k on the clock, I have no idea if it's the original fan.....

[mudder110]

yea i had the same replaced my head gasket 100,000ks ago,blew back of no 4 just oil not water,after that towed our camper from cairns to mt isa up through the gulf, was fine on the flats and dirt soon as we hit hills or sand started to get warm, up around 80 opened up the heater and she cooled a bit new it wasent normal had not done it before, put a new radiator in extra cooling row now great pulled a ton and a half up the toowomba range raised a bit but that was a bad gear change allso running a v8 thermostat dont know if that makes a differance seemed like a good idea at the time dont have spotties just a winch i think they are a badly desiend cooling system
allso running full maxi drive conversion,heavy cvs, wrangler muddies,2inch lift,stronger steering arm,heavy bash plate,front diff guard jackable side steeps,warn winch,bigger intercooler,front diff guard,double cardon front shaft,

[justinc]

That is the key, these systems are way too small for heavy hard working Defenders etc in high ambient temps, so the rad that IS there needs to be exemplary.
A bigger more efficient radiator can only help:D

JC

[rick130]

That is the key, these systems are way too small for heavy hard working Defenders etc in high ambient temps, so the rad that IS there needs to be exemplary.
A bigger more efficient radiator can only help:D

JC

I've thought more than once over the years of installing a big oil/air cooler to take some load off the cooling system, as IMO the current oil cooler is massively undersized too.

[justinc]

Certainly rick, in a Defender It would be quite easy to use a County full width radiator, replumb a full width front mount IC and then still retain a seperate engine oil cooler and A/C condenser. Using the extended 110 grille it'll all fit, well mine does I had to move the rad back about 20mm because I have a ginourmous 75mm thick intercooler....but a Tdi doesn't need to be that huge.
Or Just fitting the Td5 rad and intercooler pack will be pretty easy, all the brackets bolt straight in to county v8/ isuzu, and Tdi defenders. You just have to make up a pair of lower rad support plates like the Td5 has . That is how we did the last Isuzu conversion, used the Td5 rad and IC, very minimal mods to plumb it and fit it all up, cooling system is fine using the Tdi expansion bottle and the vehicle weighs in at 3400Kg in touring duty guise, temps seem fine.


JC

[goingbush]

Those huge lights arent going to be helping the situation


I just got home from touring NSW, up to Lightning Ridge via Dubbo, then Bourke, Cobar to Ivanhoe , Mungo & home via Balranald
Only saw one other Defender the whole trip

[camel_landy]

WOAH STOP RIGHT THERE!!!!

None of you have checked the obvious... Is the temp gauge actually giving you the correct information? It may well end up being a blocked rad, etc... But check the simple & cheap stuff first.

Borrow/buy a laser thermometer, go for a drive, reproduce the problem, jump out and measure the temperature. The ideal place will be the thermostat housing.

The reason I say this is that a faulty earth to the engine will make the temperature gauge over sensitive and you'll think that you are overheating when actually you're not.

M

[wrinklearthur]

Borrow/buy a laser thermometer, go for a drive, reproduce the problem, jump out and measure the temperature. The ideal place will be the thermostat housing.

If this hasn't been done already then doing this should be first on the list.


The reason I say this is that a faulty earth to the engine will make the temperature gauge over sensitive and you'll think that you are overheating when actually you're not.

As the engine temperature rises, the temperature sensor allows more current to flow through it, so by removing the wire to the sensor ( open circuit ) when the ignition is in the run position, the gauge shows cold and then by placing a test light ( low impedance ) between the wire that goes back to the temperature gauge and a good earth the gauge then should show a hot reading.
So therefore, poor earthing somewhere between the alternator and the negative terminal on the battery will allow the voltage to rise between the engine block and the battery. This then can show up as a faulty hot reading on the temperature gauge.

Check that the earth straps between the battery to the chassis and the earth strap from the flywheel housing to the chassis are in good condition, not frayed and most important ! where the surfaces are that they are bolted on to, is as clean as, use some conductive grease on the surfaces and everything is then done up tight .

The next earth / current path to check is between the side of the temperature sender body and the engine block. Turn the ignition switch to the run position and on the 300TDi you should hear the fuel cutoff solenoid click once as it engages, then using a multimeter, measure for voltage between the engine block and the body of the sender unit, there should be a reading showing zero volts.

Any voltage reading at the sensor to the engine block, means there is poor current path somewhere between the those two measuring points , so investigate !

This check will not show up an internal fault in the sender however, to determine the condition of a sensor, substitute with a known good or new unit.

.

[weeds]

Thanks guys.....if I was at home I would have access to a laser temp gun........but I'm touring NSW

Re: earth faults I good never get the OEM gauge working right no matter how many earths I ran that why I went to a mechanical gauge no earth from memory. The temp gauge continues to show the temp after you have shut down and removed the key.

We came off the high plains this morning and it's been pretty flat going ranging between 90 and 95

All good reading

[PhilipA]

I was going to make the point that if it was the gauge, then why only overread on hills?LOL Clairvoyant electrics?
From what you have posted , IMHO you probably have a number of factors that add up to cause the overheating problem.
1 Spotlights and winch reducing air input
2 disconnected heater core
3 maybe bad VC
4 maybe partially blocked rad( although AFAIR you said it was new.)
5 maybe bad thermostat.

Perhaps try the cheapest things first.
1 thermostats are so cheap ( if conventional type) that it pays to replace, so it can be eliminated.
2 clean up in front of the radiator( move horns if in the way, and test without the spotlights)

Then you get to the harder stuff!
I have read about Nissan Patrols that the problems can be fixed in some cases on TD42s by just moving stuff.
Another suggestion may be to make up your own tropical grille with some mesh.
Regards Philip A

[wrinklearthur]

Like Philip A said, why should a meter be faulty up hill only? :angel:

When pulling hard a engine produces the most heat, so is your engine making more power therefore more heat, in other words has the pump been tweaked or is the boost set a bit higher than normal?

With 'Fred' I suspect the boost isn't quite right for the pump settings, does anyone else hear 'cricket' noises from under the bonnet when pulling at 2,500RPM? :p

.

[rick130]

WOAH STOP RIGHT THERE!!!!

None of you have checked the obvious... Is the temp gauge actually giving you the correct information? It may well end up being a blocked rad, etc... But check the simple & cheap stuff first.

Borrow/buy a laser thermometer, go for a drive, reproduce the problem, jump out and measure the temperature. The ideal place will be the thermostat housing.

The reason I say this is that a faulty earth to the engine will make the temperature gauge over sensitive and you'll think that you are overheating when actually you're not.

M

It's a mechanical gauge !

[camel_landy]

Like Philip A said, why should a meter be faulty up hill only? :angel:
In the case of the standard sender & gauge on the 300TDi, a faulty earth can make it more sensitive.

The climbing the hill, just adds extra load, which will make the temperature rise... That faulty earth makes it look as though it is overheating!!!

...and before you all start picking holes in it, I'm telling you this from first hand experience!!! Took me sodding ages and cost a small fortune to find that my Defender was 'Overheating' because of a faulty earth!

M

[Defendozer]

In the case of the standard sender & gauge on the 300TDi, a faulty earth can make it more sensitive.

The climbing the hill, just adds extra load, which will make the temperature rise... That faulty earth makes it look as though it is overheating!!!

...and before you all start picking holes in it, I'm telling you this from first hand experience!!! Took me sodding ages and cost a small fortune to find that my Defender was 'Overheating' because of a faulty earth!

M
This is very true! Two of our 300Tdi defenders had the same problem, a bad earth causing the temp gauge to rise on hills.. Also when the lights were turned on or the heater used the temp would go up dramatically. I just ran a new earth from the gauge to the engine, has fixed the problem till I get around to buying a VDO gauge..

[fesm_ndt]

I seen many people recommend replacing the standard gauge with a VDO unit. Anyone got a model number as another item to add to the ebay shopping list?

Also what about the tropical mod and blocking the hole in the header tank as I heard that causes these symptoms, the hole that is?

[wrinklearthur]

Also what about the tropical mod and blocking the hole in the header tank as I heard that causes these symptoms, the hole that is?

Thanks fesm

That was the first time that I had heard of that mod and thanks Mate! I did pounce on that info.
This also explains to me why when I have done reverse flushing of a 300TDi radiator that it hasn't been entirely successful, compared many tractor and truck radiator cores that I have washed rubbish out of.

I found this posting on another forum that does explain that tropical mod.

Ref; Overheating 300tdi - Technical - Cape Land Rover Club News Site (http://www.clrc.co.za/ClubForum/tabid/125/forumid/3/threadid/110/scope/posts/Default.aspx)


If you own a Defender or Disco with the Tdi 300 motor , are you aware of the strange mod introduced by Land Rover to the radiator ? This mod really appears to be an example of the tea girl altering specs , while the engineers were out of the office. If this has caught your eye , read on...

The hot coolant enters the radiator at the top left side and exits at the bottom left side.(as viewed by the driver in the car ). I would expect that the coolant would have to follow a path that spreads its flow over the entire radiator . But no , there is an opening inside the radiator, about the size of a R5 coin, that allows coolant to by pass the main radiator core and flow directly out of the bottom and back to the engine. Over time the radiator core will certainly show a build up of calcium deposits , thereby forcing an ever increasing portion of coolant to by pass the core. Small wonder then that 10 year old Tdi ' s often develop cooling problems.
There are cases reported where this by pass hole is closed up , eliminating overheating problems . Also owners with modified radiators report a slower warm up after start up.

I intennd as a precautionary measure to have my Tdi rad recored and to close up this by pass .

[rick130]

Arthur, if you look down through the bleed hole in the LH tank you can see the (bleed) hole in the divider, it's at least the size of a 10c piece !
It's a common mod to have it blocked when you have the tanks off for rodding, etc.

Crazy......

[rick130]

Fesm, the mechanical gauge which I use is VDO part # 180 077 022.

This has a 1600mm capillary, 40-120*C range and the thermowell supplied with it screws straight into the standard sender spot (1/8"-27NPTF)

[wrinklearthur]

I just ran a new earth from the gauge to the engine, has fixed the problem till I get around to buying a VDO gauge..

Running that earth can be for piece of mind even if there hasn't been any temperature spiking issues, also there is some real doubt that the sender unit can recover to proper working order after being exposed to overheating, when having problems this sender unit should be replaced.

Along with the effect of electrolysis between the engine and those sensors causing stray currents, it is no wonder that people give that Land Rover gauge the flick and look at fitting a VDO gauge.
.

[rick130]

Like Camel Landy, I had temps spiking years ago causing me coniptions !

Once was in a heavy shower of rain on a hot day crossing the range here, the temps went to the max with the stock gauge, it wasn't until I turned the wipers off that they went back to 'normal'.

That was enough for me and crook earths, I just ordered a mechanical gauge the next day and that was probably 8 or 9 years ago.

Problem solved.

[wrinklearthur]

That was enough for me and crook earths, I just ordered a mechanical gauge the next day and that was probably 8 or 9 years ago. Problem solved.

This earthing problem has been a recurring theme in older Land Rovers and it has happen with both Discovery's and Defenders.

Has anyone chased out the actual places where the earthing is bad?

I have read on this forum of the earth point in the dash of a Defender causing other problems as well, due to the earth wiring making improper contact with the body because of paint under the terminal lugs.
.

[rick130]

It was the dash earth on mine, but there were so many stories of the stock gauge not registering, or registering far too slowly when things were array so I ditched it.

[wrinklearthur]

Does anyone know of a instrument binnacle made for the centre top of the dash for Discovery '94 onwards?

[schuy1]

Does anyone know of a instrument binnacle made for the centre top of the dash for Discovery '94 onwards?

I used this 1 on the defender and it works well. It could be a little less bulky IMO but is really solid, being alloy and steel , unlike the plastic 1s! :)
http://www.raptor-engineering.co.uk/discovery-range-rover-console

[URL=http://s1076.photobucket.com/albums/w459/schuy1/?action=view&current=DSCF0162.jpg]https://www.aulro.com/afvb/images/imported/2012/09/298.jpg[/URL

[rick130]

Mud make two plastic ones for the Deefer, not sure if they fit the Disco dash ?

MUDSTUFF.CO.UK, Mini MUD Pod, Land Rover Defender Solutions: West Yorkshire (http://www.mudstuff.co.uk/MUD_pod_mini.shtml)

MUDSTUFF.CO.UK, MUD Dashboard Pod - 'MudPod', Land Rover Defender Solutions: West Yorkshire (http://www.mudstuff.co.uk/MUD_pod.shtml)

[fesm_ndt]

Thanks fesm

That was the first time that I had heard of that mod and thanks Mate! I did pounce on that info.


yep seems everyone who has done it thinks its great. I was thinking of buying a heavy duty radiator from the UK but I am worried this bypass hole would still be in it, so I will try to get a 5 core made in KL.

I read somewhere that the hole, which I also think daft is there to help get air out of the lower tank as the inlet and out let are on the same side (also daft). However given the good reports I think I will just take a little extra time filling and plug the hole (Pinzgauers take forever to fill as there can be loads of air pockets in the system, its just a matter of paitience).

[weeds]

Climbing the range to armidale and the temp is climbing again in the big hills....backing off when the gauge approaches 105.

Gives us more time to take in the scenery.

[fesm_ndt]

Fesm, the mechanical gauge which I use is VDO part # 180 077 022.

This has a 1600mm capillary, 40-120*C range and the thermowell supplied with it screws straight into the standard sender spot (1/8"-27NPTF)

cheers..... I owe, I owe, off to Ebay I go

[wrinklearthur]

Mud make two plastic ones for the Deefer, not sure if they fit the Disco dash ?

MUDSTUFF.CO.UK, Mini MUD Pod, Land Rover Defender Solutions: West Yorkshire (http://www.mudstuff.co.uk/MUD_pod_mini.shtml)

MUDSTUFF.CO.UK, MUD Dashboard Pod - 'MudPod', Land Rover Defender Solutions: West Yorkshire (http://www.mudstuff.co.uk/MUD_pod.shtml)

They do and this is one.

http://www.mudstuff.co.uk/products/MudPod/Discopod%201.jpg

.

[rick130]

yep seems everyone who has done it thinks its great. I was thinking of buying a heavy duty radiator from the UK but I am worried this bypass hole would still be in it, so I will try to get a 5 core made in KL.

I read somewhere that the hole, which I also think daft is there to help get air out of the lower tank as the inlet and out let are on the same side (also daft). However given the good reports I think I will just take a little extra time filling and plug the hole (Pinzgauers take forever to fill as there can be loads of air pockets in the system, its just a matter of paitience).

Dual pass rads have been around forever, all the race cars I ran/worked on used them, we just had small bleeds at the top of the bottom section of the header tank to make sure they were bled.

All L/R would need was a 1/16" hole, but I'm guessing they were concerned they would block up.

The other alternative is a spigot and return back to the main header/fill bottle as the t/stat housing and top of the radiator do.