Running temperature / cooling fans

Hi there, I'm a newbie here and as a TF owner. I've introduced myself elsewhere on the forum.

The only TFs that I've driven are my own and a couple of others that I was considering buying, so my knowledge of what they "should" be like is sketchy.

I have driven my TF 135 several small trips and two trips of 60-ish miles and I've never noticed either cooling fan cutting-in. It's been pretty warm here lately, but it's Scotland, so that's been 18-22 degrees ish. The temperature gauges behave exactly as I would hope - up to a little under half way on the coolant temperature gauge after 5 minutes or so, and it stays there solidly for the full time using the car.

Of course, I'm a hypochondriac , and paranoid about the car overheating. The fluid in the expansion tank behaves fine (not up or down when hot). I've tried disconnecting the fan temperature sensor, and the fans burst into life.

However, the engine bay does seem pretty hot to me, and the boot does get fairly warm.

So, Is this behaviour normal, or do I have a problem such as a malfunctioning sensor?

Thanks, Ryan.

For peace of mind its worth checking the cooling fans back and front are working. Search on here for the locations of the sensors that control the fans and bridge or unplug accordingly to check the respective fans are working. Beyond this it's worth adding a low coolant alarm, something that really should have been fitted as standard. DIY fit, not expensive and great for peace of mind

I had a chuckle at 18 - 22 deg being pretty warm, here in Oz most folks are reaching for their winter woollies at 18 deg!
Not me most here think I’m mad for thinking that’s comfortable tee shirt weather……must be my Scottish ancestry.

Given that the engine is a very snug fit in its bay and the fact that being hidden back there, offers bugger all air flow around it, means these things do retain shitloads of heat.

In order to help properly disperse this heat and reduce the heat stress on the engine, and any components in the engine bay that wouldn’t enjoy the heat soak, I fitted two small fans to the under side on the grill at the top of bay to push air out as the air flow is pretty poor, yes the is a fan that blows air in from outside sucking through one of the side vents but this airflow mostly just takes the path of least resistance and disperses out under the car without disturbing the hot air trapped in the upper engine bay.
I used some 12V fans from a quad bike, they look like bloody computer fans and probably that’s what they basically are, but as they are from a quad bike they should be pretty tolerant to mud, muck and water. They’ve been on there for donkey’s years and have given no trouble at all.
I wired them in with a relay that takes it trip feed from the in feed of the engine bay fan.
They pump out an amazing amount of heat!
This helps to keep the wiring insulation from baking hard, the electronic components from being cooked, reduces heat stresses on the engine itself and any plastic or rubber bits that might deteriorate over many extreme heating and cooling cycles.
I did a write up here some years ago, you might do a search of the archives.

Try here

In fact you should checkout the archives to gain the wisdom of the ages anyway…… mind you only take the wisdom on board, leave the stupidity behind.

And yes you Must fit a low coolant alarm, no ifs or buts will be tolerated, it is pure insanity to run these cars without one.
The cost of fitting one is insignificant in comparison to a cooked engine!….which is a fairly likely outcome if one isn’t fitted.
You’ll get no pity from me or anyone else with any sense around here if you don’t!
I use the Browns & Gammons low coolant alarm and can highly recommend it, but I do understand that there are alternatives, although I would avoid the nasty el cheapo type that involves screwing self tapping screws into the plastic header tank.
Remember the quality remains to be enjoyed long after the price has been forgotten.

Interesting about the low coolant alarm - I've been off to the Brown and Gammons website to have a look - it doesn't look too complicated a job either. (?)

In the meantime, as my coolant levels haven't altered, I take it that the fans haven't come on because the engine hasn't needed them, and stop worrying?!

Nothing more needs to be said others than to reiterate the low coolant sensor & even though the needle in the temperature gauge is in the correct place now, which is a good indicator of an adequate coolant supply, it can rocket alarmingly, usually when you’re concentrating on other things. A dedicated sounder is a must, something that’s obviously not a spurious squawk that might have emanated from a ‘phone.
It was interesting to look back at Cobbers handy work from years ago with particular attention to his supplementary fan, I’m in the middle of sorting a similar system using four 80mm fans mounted on the boot lid. They may resonate & use the boot space as a sound box, I’ll only know the day after the parcel arrives.
M

With the weather as it is at present my TF 135 has had a pleasant trip to Whitby and back to Leeds. Periodically when in stationary traffic the fans have been on . As I pulled up at home after a great plate of Fish and chips at the Fisherman's Wife in Whitby, both the fans came on . The rad fan switched off after about 20-30 seconds but , the engine bay fan stayed on for a further 3 minutes with the ignition off . Outside air temperature must be touching 80 so, I think thats a good guide . Temperature gauge never troubled me all day , even flogging the car up Garrowby hill to the coast .
John .

The radiator fans cut in at the below temperatures for TF135. Fans normally would only come on in UK when car is stationary or in traffic. Not all TF's have 2 radiator fans. Standard on Aircon models or SAIC cars. Engine bay fan should only come on on a very hot day and you have been giving it a bit of a go.

1st Cooling Fan Switch ON 102c OFF 96c
2nd Cooling Fan Switch ON 117c OFF 112c
Engine Bay Fan ON 75c OFF 65c
Engine Bay Warning Light ON 130c OFF 110c

The thermostat starts to open at 86c and is fully open at 102c

Cheers, Mark

These are really useful figures & a very good guide to those who are obsessed with keeping things within designed perimeters.
As sw’cooper commented earlier it’s been hot, the mercury in the thermometer hasn’t worked as hard as this for a while & if the doom mungers are correct it’s going to get hotter with every passing year. I reflected on those thoughts last year when I grounded out on a snowdrift in the Landy; only the second time in all the years of Land Rover ownership I’ve had to dig out.
Cobber mentioned his fitting of a supplementary cooling fan & I’m doing the same only I’m not shifting the same volume of air & I want to control it via a thermostat, these figures will become datum points for later experiments.
Thank you Mark.
M

Thanks everyone. Very interesting and useful. Everything seems to be working to it's design with no real warning signs. I should stop worrying and enjoy the car - but the low coolant alarm is on my list.

I was wondering if the front radiator fans can be tested using Pscan? When I restarted my car after its refurb, it was winter and I let the engine run until the fans kicked in to test them.
Now I am driving it around in the summer, I haven't noticed them ever switch on in normal use, but the temperature gauge is a stable normal.

The engine bay fan nearly always runs for a few minutes after driving in the town and defiantly kicks the heat out of the compartment.

When rebuilding the car, I noticed that the fan is positioned to flow air across down through the gap behind the bulkhead heatshield and over the top of it (around the exhaust manifold). So in my pinion, the fan is mainly there to stop the fuel tank getting too hot. I don't think that the engine itself is bothered by the high air temps because all engines run at high temperatures.

By the way, I have noticed that there is an Air Duct in Front Bumper (https://rimmerbros.com/ItemImages/Large/DXJ000020.JPG). My car does not have one fitted. Is this because it is missing or because it has air con?

BruceTF135 does a very good low coolant alarm. I fitted one on my 115 a while ago and have just bought another for the 135. The sensor can be glued onto the expansion bottle, picks up when the level is low and makes a noise that cannot be ignored.

Im adding a delay unit this time to avoid the likelihood of false alerts on hard cornering - not that i have experienced any but whilst pre built 12volt delay circuits are 2x for £ 5 on Ebay it seemed a useful enhancement.