300TDi designed operating temperatures please

[Guest otchie1]

Having just dropped the 300TDi into the 110 and swapped the temperature gauge (with new matching sender) for one that reads in actual degrees I was a bit startled to see it running at 95deg C. I checked the opening temp of a new LR thermostat before I stuck it in and that was around boiling so I can believe it but having spent a few months looking at my S2 gauge sitting at 80 deg I can't help but feel a little anxious.

Anyone know the designed operating temperature ranges and what constitutes too hot for a 300TDi?

[Pete Attryde]

I have a thermocouple installed in the cylinder head of my 300TDi and that normally reads around 200-210 F which is around 93-98 C.

Pete.

[mmgemini]

You haven't said what make of gauge and if a short dial or a full 270 deg dial.

My 300Tdi with a SPA analogue stepper 270 Deg dial reads 75/ 80 deg C in all weathers going to 85/ 6 Deg in Namibia in 49Deg C ambiant.

My temperature warning light is set at 94 Deg C

HTH

mike

[western]

Standard stat for a 300Tdi should be a 88 degree opening ERR3291.

[Guest otchie1]

Standard stat for a 300Tdi should be a 88 degree opening ERR3291.

Hmmm, the orig part I bought only opened when the water was on a rolling boil. It was a ERR3291; waxstat though so maybe a sustained 88 deg would have achieved the same - at the time I was only making sure that it did open.

FTR it's a TIM electric short dial so figures only to the first 4 dp please

I know the rear A/C type thermo housing thermo-switch throws at 100 C so I presume LR start to get worried sometime a little North of that?

[western]

if you watch it closely [without getting scalded] the stat should begin to open at 88 degrees, my 200tdi runs a 82 stat

[Guest otchie1]

if you watch it closely [without getting scalded] the stat should begin to open at 88 degrees, my 200tdi runs a 82 stat

Ahh, makes sense. So an engine temp below 88 deg underload would be unnatural given an 88 deg stat and I should expect a normal operating temperature of 'around' 90 deg.

Any idea on a dangerous temp figure?

[cipx2]

I know the rear A/C type thermo housing thermo-switch throws at 100 C so I presume LR start to get worried sometime a little North of that?

The one in front kicks the compressor out at 115C so LR thought you should still have a running engine at that temp. Not something I would agree on an old vehicle (>10 years).

Normally, the max temp is given by something LR never bothered to fit - a temp switch in the cyl head/block that would trigger a warning light in the dash. In the absence of such a complicated device, much too expensive to be factory fitted, 115C should be taken as the last frontier IMO.

I set the alarm at 100C and it usually happens to go over that temp on long uphills in summer.

Long uphills = more than 1000 feet difference in altitude at high speeds (>50-70 mph) in 4th, engine load about 3/4 or so (0.9-1 atm boost out of 1.2 atm max), not towing, medium load, A/C turned off at 100C

Summer = over 30 degrees.

I get precisely 95C in my Disco at 85 mph, no A/C, no load (only me driving), flat motorway, 30 degrees ambient, sunny. I normally drive at 70-75 mph and the temp stays around 88C in the same conditions.

Engine at tick over for 25 mins (revved for like 10-15 secs every 3-4 mins), A/C on, temp went from 88-90 degrees when I pulled over up to 100C in a hot summer day (40 degrees).

In the winter (-10 to +5) I get 82C which is about the lowest temp I got driving at 60 mph flat for at least 30 mins.

The bits in the cooling system of my vehicle:

- the rad is the factory one, it's clean on both inside and outside, not a fraction of an inch missing from the fins (rot or mud is out of the question, maybe a number of squashed flies here and there)

- all new and genuine: thermostat, water pump, hoses (the hoses are 2 years old)

- new borg warner (oem) viscous coupling

So 95C in your engine could be quite cool or too hot for a given set of operating conditions. Without the op conditions I can't tell if it's right or wrong.

[Guest otchie1]

Thanks for that very detailed answer. Seems that 'about 90C' is well within spec and that I should stop worrying.

Also great to know about the front 115C thermoswitch - I'll wire a 'STOP NOW' alarm into that one.

[Aragorn]

i'd be proper bricking it if i saw 115c in my motor!

Given that most cars with electric cooling fans will cut them in at 100c, i wouldnt really like to see much more than 105-110c.

IMO a warning light shouldnt come on at ABSOLUTE max, it should come on a little bit before that. I'd be setting my warning light at 105c, at least that way you can lift off the throttle a bit or ram the heater on full bore to try and get it under control while you figure out a safe place to stop, rather than it coming on at 115 when the engines about to roast itself, and having no time to do anything.

[mmgemini]

What are we actually talking about. The cooling temperature or the auxillary cooling fans fitted when AC is fitted.

I was talking about the running temperature of my 300Tdi. Not what the aux fans are switched at.

I have my warning light set so I can switch on the fan to cool then enging BEFORE it reaches maximum temperature and melts.

AFAIC any gauge other then a full 270 Deg face reading cannot give accurate readings.

mike

[Guest otchie1]

What are we actually talking about. The cooling temperature or the auxillary cooling fans fitted when AC is fitted.

I was talking about the running temperature of my 300Tdi. Not what the aux fans are switched at.

I have my warning light set so I can switch on the fan to cool then enging BEFORE it reaches maximum temperature and melts.

AFAIC any gauge other then a full 270 Deg face reading cannot give accurate readings.

mike

I was originally just concerned at the leap from 80C to 95C although I appreciate the huge differences between the two engines.

I was interested just in whatever anybody's temp gauge actually read as they used their vehicle so I could get an idea of the range of 'normal'.

I have my electric fan (viscous removed) to cut in at 92C measured at the thermo housing and do not have further aux cooling or any AC components other than the thermo housing.

Obviously 115C is near destruction so I was planning on a a very audible warning alarm just in case I hadn't noticed the steam pouring out of the bonnet.

SFAIK the sweep of a gauge only allows for greater precision within the range of the sender. A full sweep will enable you to better differentiate 89C from 90C without squinting but apart from that it is no more accurate than a partial in that an indicated 90C on both should be 90C.

I've never seen any test data comparing Smiths to VDO to MotoMeter to Tim so I can't guess as to their relative accuracies but if I really need accuracy I'd go with multiple thermocouples and a digital readout. Thankfully I don't need any of that so a simple 'generally above 85 but less than 95' is good enough for me. Can you tell I drive a Series 2 as well?

[mmgemini]

I was originally just concerned at the leap from 80C to 95C although I appreciate the huge differences between the two engines.

I was interested just in whatever anybody's temp gauge actually read as they used their vehicle so I could get an idea of the range of 'normal'.

I have my electric fan (viscous removed) to cut in at 92C measured at the thermo housing and do not have further aux cooling or any AC components other than the thermo housing.

Obviously 115C is near destruction so I was planning on a a very audible warning alarm just in case I hadn't noticed the steam pouring out of the bonnet.

SFAIK the sweep of a gauge only allows for greater precision within the range of the sender. A full sweep will enable you to better differentiate 89C from 90C without squinting but apart from that it is no more accurate than a partial in that an indicated 90C on both should be 90C.

I've never seen any test data comparing Smiths to VDO to MotoMeter to Tim so I can't guess as to their relative accuracies but if I really need accuracy I'd go with multiple thermocouples and a digital readout. Thankfully I don't need any of that so a simple 'generally above 85 but less than 95' is good enough for me. Can you tell I drive a Series 2 as well?

I'm basically running the same set-up. Fan on mine cuts in a at a different temp. I have a switch on over ride switch as well.

I can watch half degree changes on my gauge !!d

One other item that I recomend for the 300Tdi is the coolant loss sensor.

mike

[Guest otchie1]

I'm basically running the same set-up. Fan on mine cuts in a at a different temp. I have a switch on over ride switch as well.

I can watch half degree changes on my gauge !!d

One other item that I recomend for the 300Tdi is the coolant loss sensor.

mike

Coolant loss is next on my list. Not sure whether to go with a RR expansion bottle cap/sensor, something robbed of a BMW or something scratch built. Probably whichever I have to hand when a get another roundtoit.

[mmgemini]

Look here....

http://forum.difflock.com/viewtopic.php?t=10972

mike

[crewcab 110]

i am having a nightmare with stats every single one wont open unless its in a pan or raging boiling water when they are suppossed to open at 88 i pulled a waxstat out of an old 300 tdi tested in hot water just hot kettle water opened as it should put it in my defender 300 and it is now spot on why can i not buy a thermostat that works properly ive tried genuine and cheepo not one will open  in boiled kettle water you have to have the water boiling and bubbeling ive now removed the viscous fan and its still spot on as i have an electric one too,anyone had this same issue.

ive messaged britpart as this is were they are all coming from see what they have to say as ive got 3 diffrent ones going back as they deffo dont open at 88 or in hot kettle water 

Edited October 30, 2023 by crewcab 110

[simonb]

The quality of current thermostats is best described as poor, I always test them like you have before fitting. Many doen't open till near boiling point. Try a QH one, or one from a motor factors, rather than a LR "specialist". Radiator caps for a series 3 are equally bad, most new ones seem to leak - the length of the spindle is no where near to what an old genuine one is.

[Sigi_H]

Just an idea. Maybe the stat needs the pressure in the system to open correctly

 

[Maverik]

I've had exactly the same issues as you, multip brand new thermostat's not working, and I thought genuine LR was the way to go, but recently they've been just as unreliable.

Something I have found is that on first use, they can stick closed, once this initial opening is completed then they work more or less as they should.

[Mo Murphy]

There was some nonsense written in this thread 14 years ago ! 🤣

Mo

[Sigi_H]

5 hours ago, Mo Murphy said:

There was some nonsense written in this thread 14 years ago ! 🤣

Mo

Never ever !! 😂

To be honest, I am only intertested in Oil Temp above 60° C and Water temp below 100°C.

I get attentive when water temp above 100°, but without panic.

My knowledge and experience says, the speed of rising of these temps tells more than the temps themselves.

[FridgeFreezer]

On 10/30/2023 at 12:36 PM, crewcab 110 said:

ive messaged britpart as this is were they are all coming from

Well, there's your problem...

On 10/31/2023 at 7:04 AM, Sigi_H said:

Just an idea. Maybe the stat needs the pressure in the system to open correctly

Nope, it just needs to be decent quality which is surprisingly hard to find these days.