Help Diagnosing my Td5 Cooling issue

[CU55TM Disco]

First thing I did when we purchased our disco late last year, was have the water output from the head moddified to accept a temp probe from the MadMan, and change the thermostat.
I was sold a Britpart thermostat, and and assured from the w/shop that "we always use these ones on customers cars, and never have a problem"

Good enough I though, and off I went.

Now, over the last few months I have been diagnosing some MAF faults, and took a few dumps from my Nanocom, one of the things that was noticed by another member here, was that my coolant temp@ cruise, was sustantially higher than other peoples, read 97 Degrees @ Highway speeds (temp take with nanocom).

SInce then I have changed coolant, and had my madman finally fitted.

MadMan confirms what the Nanocom is saying, and at highway speed, I am getting about 97 Degrees coolant temp. Puttering around town, I might get down to 92, and somewhere in between.

New coolant was Nulon Red, stuck the hose in, and have it as good of a flush as I could.

What I have noticed is, that after a decent drive, long enough to get upto operating temp, and quuickly popping the bonnet when arriving home, is that the outlet from the radiator to the thermostat isnt hot, and the RHS radiator tank is cold to touch, wheres the LHS is untouchable.

So, do I have a crook radiator, and its not flowing coolant from one side to the other, or, do I have a wonky thermostat, that isnt opening at temp? :confused::confused::confused:

I have checked and double checked its orrientation, and am satisfied that its installed with the outlets facing their correct directions. Surely the OEM radiator isnt THAT efficient that it can drop +90 Degree water down to sub 60 degree temps!

The second part of this question, revolves around replacing the thermostat AGAIN, with a genuine one this time, im thinking of going to a PEL500110, 82 Degrees w/Light spring, as the heavy spring jobbies seem to be for cooler climates to get the heater warmed up sooner, correct???

[PhilipA]

My guess is crook thermostat.
I have an 82c standard spec and it runs at 82-85 around town and on highway except on long grades towing.
Regards Philip A

[roverv8]

MadMan confirms what the Nanocom is saying, and at highway speed, I am getting about 97 Degrees coolant temp. Puttering around town, I might get down to 92, and somewhere in between

careful buying aftermarket thermostats just by the part no,
I bought a B***m**h thermostat PEL500110 (supposed to be 82deg)
Fitted to my D2 & had the same running temps as you, pulled the thermostat to find it had 92deg stamped on the inside metal part of the thermostat....
paid top $$ & couldn't get a refund because I had fitted it to my vehicle.
I even e-mailed B***m**h complaining about the thermostat & the running temp but I never received any response from them...
May be the wrong thermostat ended up in the wrong box, i don't know but it ended up Wasted time & money.

Finally found a thermostat on evilbay with the 82 deg on the add

[sierrafery]

When it's really warm outside after a longer drive the thermostat is supposed to be fully open no matter what initial opening temp it has so that's not an issue as long as it's not blocked closed IMO, did you fill and purge the system as in the book with tank raised above the bleed hole?, you must be certain that it's airless first of all, release gently the bleed screw after a longer drive with engine running and if you see bubbles or air bleed it well before you do something else, also for high running temps it's not uncommon that the viscous fan to not lock well then the cooling will be reduced, try to stop it with a rolled newspaped with eengine running when the radiator is hot and if it stops that's a problem too, also the tank's cap must be completely tightened

[discorevy]

Agree it sounds like thermostat, you probably have as you say ,a heavy spring 92 degree one , easy test which I do even with new ones is to put in a pan with a thermometer to check they work ,this can save work later on .
Sierrafery , 92 degree thermostat will result in approx 92-97 coolant temp ( which can go a lot higher towing up hill on a hot day)
82 degree means 82-87 coolant temp which gives more margin
Cheers

[CU55TM Disco]

I will be buying genuine, won't be burnt with a non genuine unit again.

[CaptainJack]

I will be buying genuine, won't be burnt with a non genuine unit again.

Ive got a V8 not a TD5 but recently went through a similar cooling issue.
I bought a 82 deg thermo of ebay - it runs all day now at 87/88deg, but initially i had issues.

What i found it that i installed it according to the diagram in the latest RAVE CD and the diagram has the thermo the wrong way around.

When you but the 82 deg thermos off ebay, they do not have the "PUMP" side marked, so if you follow the rave diagram you will put the wrong side going to the rad.

I did this initially and my temp was running high 90s

Turned it around and dropped straight to 87-88 deg and never moves either highway or idle.

Here's a link to my other post on this

http://www.aulro.com/afvb/discovery-2/216666-hot-v8-post2333247.html#post2333247

[CU55TM Disco]

I've checked and checked and checked again my orientation and I'm 99% sure that it's correct.
I have the little kick-out going to the pump. 92528
I found this pic on the net somewhere, the bypass and pump hoses are getting hot, but the rad pipe is still cold. It's as though the bypass isn't blocking off and the water is just going the easiest way, and not through the radiator.

I'll be gutting the T-stat tonight or tomorrow, and blanking the bypass hose to see what happens, see if I can get some flow through the rad and what sort of temps I get then.

[discorevy]

Gutting it will not tell you much unless you are prepared to drive it pretty hard for half an hour or so to get it to operating temperature
Why not just test it if you are going to remove it anyway?

[roverv8]

I've checked and checked and checked again my orientation and I'm 99% sure that it's correct.
I have the little kick-out going to the pump. 92528
I found this pic on the net somewhere, the bypass and pump hoses are getting hot, but the rad pipe is still cold. It's as though the bypass isn't blocking off and the water is just going the easiest way, and not through the radiator.

I'll be gutting the T-stat tonight or tomorrow, and blanking the bypass hose to see what happens, see if I can get some flow through the rad and what sort of temps I get then.


it sounds more & more like the thermostat is shot & stuck closed, forcing coolant through the bypass, as when the thermostat opens it puts pressure on the bypass valve to close & go through the thermostat

P.S
For the sake of your engine just fit a new thermostat, & double check its installed the right way....

you cannot blank off the bypass either, as in the 1st diagram, the cold coolant comes in through the bypass & out to the pump, as the coolant warms, flowing through the bypass to pump, it heats the thermostat (diagram 2), as the thermostat opens it allows flow from the radiator, and puts pressure to close bypass as in diagram 3.
The bypass is needed to heat the thermostat initially.

[Slunnie]

The thermostat isn't like a regular drop in one thats in the block, its an assembly with inlet/outlet pipes on it that is a part of the coolant hose system. It cant go back in incorrectly as the hoses wouldn't join up.

Just note also, the way it is designed, if the ambient air temp is cold, the thermostat increases the engine temperature by up to 10 degrees to allow for radiating heat from the block etc. It should start to open at 82 degrees and it will be completely open at 96 degrees, but 90% of the flow is hot from the engine and 10% is cold from the radiator. Also at lower revs (<1500rpm) the thermo partly closes and the engine temps will run hotter.

[CU55TM Disco]

The thermostat isn't like a regular drop in one thats in the block, its an assembly with inlet/outlet pipes on it that is a part of the coolant hose system. It cant go back in incorrectly as the hoses wouldn't join up.


There is a thread on here slunnie, with pics, of the thermostat in backwards, infact, i think there is 2! So it can be done :cool:



it sounds more & more like the thermostat is shot & stuck closed, forcing coolant through the bypass,This sounds exactly like whats heppening, i think the only cooling im getting is from the heater core, which is a worry. Not sure how long its been like this, but im going to assume since I thought I was doing the right thing, and changed the thermostat...


you cannot blank off the bypass either, as in the 1st diagramI can if the thermostat housing has no insides! this will force coolant to flow through the radiator, and it will run cold untill my new PEM101020 GENUINE T-Stat turns up!


Why not just test it if you are going to remove it anyway? I will.

[northiam]

The (my) rave Td5 cooling flow diagram on page 26-1-4 shows the thermostat flow bypass differs to your attachment? Yours makes more sense, so the rave must be wrong?
Regards

[sierrafery]

RAVE must be wrong cos it shows like the bypass flow comes against the main flow which has no logic

[CaptainJack]

RAVE must be wrong cos it shows like the bypass flow comes against the main flow which has no logic

Rave is wrong.
See my post here
http://www.aulro.com/afvb/discovery-2/216666-hot-v8-post2333247.html#post2333247

[Disco W.A]

Have you considered that you are trying to fix a problem that does not exist?
I think this is a case of I just got a gauge and I think it runs to hot.
Is it using coolant or down on power?
As Slunnie said and your attachment shows the regulator (thermostat) is not fully open till 96 degrees so you will see that temperature on your gauge.
It does not just open and stay open it will regulate how much coolant flows through the radiator depending on ambient temp and engine load.
If it's plumbed up correctly then its ok. If you want peace of mind get your radiator cleaned out and make sure your fan works correctly.

[CU55TM Disco]

I believe there is a problem,
I have compared my temp results with others, and the general consensus seems to be a TD5 should operate between 85 and 92 degrees during normal driving.

Also, regardless of how the thermostat in the disco works, the radiator should be WARM to touch, not bounding hot on one side, and ambient temp at the other. No radiator would be THAT efficient.

[donh54]

Sure you're not feeling the intercooler one side? :wasntme:

Sent from my HTC One XL using AULRO mobile app

[CaptainJack]

I believe there is a problem,
I have compared my temp results with others, and the general consensus seems to be a TD5 should operate between 85 and 92 degrees during normal driving.

Also, regardless of how the thermostat in the disco works, the radiator should be WARM to touch, not bounding hot on one side, and ambient temp at the other. No radiator would be THAT efficient.

I agree. An if it were me i would be doing a full flush, having the radiator flow checked and at least check the operation of your thermostat in hot water, and replacing thermostat as as just a start.

Problem with these cooling systems is they run with little tolerance, and for peace of mind you need to keep hunting it down until its sorted properly. I had the same with mine (although its a V8) but i spent days trying to sort it all, now i have it runs sweet and im confident it copes under any conditions.

Could be something little like a faulty thermostat, or big like a blocked radiator - at least by eliminating one at a time you will have more confidence in it all once its sorted.

Good luck and keep us posted on your findings.

[CU55TM Disco]

In saying that cap'n jack, tho cooling system must be relatively efficient, if it can effectively cool the engine with only the heater circuit! Which is essentially what's happening in my case.

[CaptainJack]

In saying that cap'n jack, tho cooling system must be relatively efficient, if it can effectively cool the engine with only the heater circuit! Which is essentially what's happening in my case.

Yes i understand what you mean, and i agree, set up correctly these cooling systems should more than cope. Problem is land rover radiators have a history of short lifespans, and when i refer to tolerance i mean they run such high temp thermos, coupled with a completely useless temp gauge in the dash, if something does go wrong, but the time you get a warning it could be all over.

In my system it was running hot, yet at highway speed, it coped so somehow even with a blocked system and a stuffed thermo it still survived.

Just FYI, i came back from a drive no long ago, after you last post i just went out and started by car again - its still hot, and after a few mins running i was feeling the radiator - its even temp all over. Not hotter on one side. Not sure if its different on the TD5 but i would think a rad would be even temp all over not hotter on one side.

With my cooling issue it was a number of things, not just a thermo.

FYI i bought a non gen thermo of roverlord via ebay - was marked 82 deg. My system runs now at 87 all day which is vastly better than with the previous thermo running high 90's

[ramblingboy42]

out in the northern south australian heat a couple of weeks ago grumble ran between 160-190F and at times showed about 198F.

at times it sat just over the 190F for a couple of hours.

I'm not sure what the margins compare like in C-F and I tried to calculate it but got stupid results from the conversion formula.

even at a constant 198F there's room for temperature rise without concern so I'm guessing that 96C is probably quite ok , especially if it's constant.

anyone else add to this?

[roverv8]

198F = 92.2 deg C

[CU55TM Disco]

That's a good temp. Low 90's I'd be happy with. At 96/97 degrees during normal driving, it leaves very little room for extra load whilst towing or fully loaded.

I'm ordering a genuine 82* from the UK this week.

[CU55TM Disco]

Fitted a GENUINE PEL500110.
Cruise temps are about 86*
Idle temps once hot are around 89-90*

Happy chappy.

Tested the BritpArt thermo with boiling water and got a bit of a trickle, compared to the OEM which was a more substantial flow.
Also, the Britpart item, had motorad or similar cast on the side, obviously made by someone else as a generic item.

[CU55TM Disco]

9311093111

The last photo shows that there seems to be an ORing or similar dislodged inside, don't remember seeing that in there when I fitted it!

Perhaps it used to work, and at some point has failed closed, or stuck closed etc.

Bit of a trap for young players! Hopefully the OEM one lasts a little longer!

93112

This is not the listed thermostat for a TD5, but a cooler 82* variant, I think meant for V8s in the USA and TD4 freelanders.

Will monitor the operation and report back with any positives or negatives.

[Roverlord off road spares]

May you should take a reading with a thermal temp laser gun , at the radiator, at the hose s at the thermostat housing ans at the engine and see what temps they all get. An 82 deg thermostat should open at that temp. what happens after that thermostat could be a different scenario. If an engine is running hot after a thermostat has done its job it could be other issues.

[CU55TM Disco]

Trip to Newcastle and back yesterday, between 84 and 86* on the madman.
Saw 90* when stationary for some time.
Much better!

[Mundy]

My temps seem far more variable than those quoted by others here and I am wondering if my 2004 manual Td5's thermostat needs replacing.

My temperature varies depending on outside temp, how fast I go, how steep the terrain is and how loaded I am.

So, the sort of ranges I get are:
1. Around town, ambient 25 deg, speed around 60 to 80kph, not too much stop start, not too loaded, gives me around 88 to 90deg.

2. Open highway, ambient 25, speed 100kph, flat or gentle hills, not loaded gives me 92-93deg

3. Open highway, ambient 35deg, speed 100kph, flat or gentle hills, loaded, gives me 98 to 100deg

4. Open highway, ambient 37deg, speed 100kph, medium grades, loaded, gives me 103deg

Temp measured with a TM2 sensor on back of block.

Also, around town, whilst the control panel temp gauge reaches normal after about 5 minutes, the TM2 sensor shows it not reaching max operating temp for 15 to 20 minutes.

Should I look at replacing the thermostat?

[discorevy]

Short answer , yes replace thermostat
Sounds as if it may be stuck partially closed , hence taking longer than normal to reach operating temp , then restricting flow at operating temp

[ramblingboy42]

I'm not so sure you should be concerned Mundy.

I leave home here and travel up the M1 and it does take me anything up to 10-mins depending on the OAT, for transmission to warm up enough for the torque converter to lock up.

Even on a warm/hot day it still takes about 10km

Sometimes my OEM temp guage doesn't even adopt it's 'neutral' position.

Guage watching sometimes gives niggling thoughts , like my oil pressure when everything is steaming hot out on the open highway it indicates about 25psi or under.

If I watch my temp guage I could get worried too, Like fully loaded all up weight hauling up the Toowoomba range or Cunninghams Gap.

100*c or a bit more is not too hot for lubricated mechanical parts to perform at, as long the cooling system can maintain it without hoses blowing etc.

aircooled VW's run very hot, so do aircooled VM & Deutz diesels.....much higher than a water based cooling system would allow.

you call , if you have cause for alarm and you feel more comfortable change it out.

[robbotd5]

Mundy
I would be more concerned with the actual coolant temp as read from a Nanocom. I have found that there is a 15-20 degree difference between the TM2 and the Nano.
For the record, my D2a hit 103 degrees (Nano) on a short sharp steep climb in second gear towing our 23ft van. But that temp dropped away quickly.
Regards
Robbo

[PhilipA]

1. Around town, ambient 25 deg, speed around 60 to 80kph, not too much stop start, not too loaded, gives me around 88 to 90deg.

2. Open highway, ambient 25, speed 100kph, flat or gentle hills, not loaded gives me 92-93deg

3. Open highway, ambient 35deg, speed 100kph, flat or gentle hills, loaded, gives me 98 to 100deg

4. Open highway, ambient 37deg, speed 100kph, medium grades, loaded, gives me 103deg

These are much higher temps than mine runs at all times. I would be also looking at flushing the radiator or buying a new one , if you find a new thermostat does not fix the problem.

Mine on open highway at 100Kmh pulling 1 tonne camper at say 25C , usually around 82C rising to 85C-88C on big hills measured on digital gauge checked by Nanocom.

At 37 C flat running while towing at 100Kmh,around 85C up to 88c on hills.

Maximum ever 103C towing camper up Alpine Way from Khancoban to Thedbo on 20C day.
I also am beginning to now wonder more and more if these high temp problems are the root cause of shuffling heads, as the hotter the engine gets , the longer the head bolts and the looser the head.

Regards Philip A

[northiam]

Running to higher coolant concentrations can be detrimental as pure water is a far better coolant than 50/50 premix.
Over concentrations can easily happen over time with repairs and top ups etc.
A 33% mix would be far better for ozzie conditions.

Interesting reading from redline thou I dont know if water wetter is suited for a D2
Regards


[url]=http://www.redlineoil.com/content/files/tech/WaterWetter%20Tech%20Info.pdf]

Too much coolant can cause overheating: Ask Smithy | CarsGuide (http://www.carsguide.com.au/car-advice/q-and-a/too-much-coolant-can-cause-overheating-7896)

[laney]

Problem here is Brit part most people I have spoken to have told me to run if offered any Brit part as they are Sud standard gear.

[CU55TM Disco]

Red OAT must be mixed at 50:50. Only the green can be dropped to 33%.

I bought a bottle of water wetter to try in the disco, but ended up going the 82* thermostat instead.


The wAter wetter I thought I read, was compatible with all coolant types.

[northiam]

From Nulons web site

Nulon RLL is the preferred coolant to use in cooling systems
fitted with aluminium radiators. It is a genuine 100% OAT
based, long life coolant. RLL is dyed its distinct red/orange
colour to instantly distinguish its unique chemistry from
traditional green coolants. It should not be mixed with other
coolants. As it is a concentrated coolant, it is to be used
at 33% to 50% by volume in soft or demineralised water.
Nulon RLL provides maximum protection against cavitation
erosion of wet cylinder liners in diesel engines. Nulon
RLL is particularly suited to vehicles fitted with aluminium
radiators. If changing from any other coolant to RLL, always
thoroughly flush the system first as cross contamination

Regards

[CU55TM Disco]

I'm sure the back of the Nulon bottle says 50:50.

[sierrafery]

My temps seem far more variable than those quoted by others here and I am wondering if my 2004 manual Td5's thermostat needs replacing.

My temperature varies depending on outside temp, how fast I go, how steep the terrain is and how loaded I am.

So, the sort of ranges I get are:
1. Around town, ambient 25 deg, speed around 60 to 80kph, not too much stop start, not too loaded, gives me around 88 to 90deg.

2. Open highway, ambient 25, speed 100kph, flat or gentle hills, not loaded gives me 92-93deg

3. Open highway, ambient 35deg, speed 100kph, flat or gentle hills, loaded, gives me 98 to 100deg

4. Open highway, ambient 37deg, speed 100kph, medium grades, loaded, gives me 103deg

Temp measured with a TM2 sensor on back of block.

Also, around town, whilst the control panel temp gauge reaches normal after about 5 minutes, the TM2 sensor shows it not reaching max operating temp for 15 to 20 minutes.

Should I look at replacing the thermostat?

Don't be very scared about that difference though cos the gauge goes to the middle(considered "normal") at 70*C and as normal operating temp is considered around 90 that might not be such big issue cos it depends much on ambiental and driving conditions too

about the thermostat IMO it's a good move to replace it if it's old cos they are loosing theyrs qualities in time anyway BUT if there will be no change after that make sure the viscous fan is locking well cos i've seen many cases when that was the problem... try to stop it with a rolled newspaper when the thermostat is supposed to be fully opened/radiator is hot and if you can then you better get a new one cos it means it doesn't have enough guts to cool well... they used to wear out in time as well

i was thinking many times about this "normal operating temp" thing and there are some unanswered questions in my mind:

the main question is: If 95*C is considered hot (nanocom will warn you at that temp on instrument mode) then:
1. why did they make the original thermostat to fully open only at 96?
2. why did they set the electric(aircon) fan to kick in only at 110(to help cooling) and stop at 105?
3. why did they set the gauge to leave the middle only at 120?

if we think that they knew what they were doing then IMO nothing up to 105 is bad cos it depends very much on environment, vehicle load and driving style:cool: