That's very useful tip above; rev to ~2,000 and watch for coolant piddling into the reservoir. Works a treat and gives me confidence that the last bit of air has left the radiator - thank you!

Now I just have to worry about the fan viscous coupling failing (if it hasn't done so already)
...and the temperature gauge being a lying little towrag.

But with the bonnet open and the engine ticking over like a Swiss watch, it's nice and drafty in there, and the aircon clutch clicking solidly in and out. And the sun shining. What's not to like!
 
That's very useful tip above; rev to ~2,000 and watch for coolant piddling into the reservoir. Works a treat and gives me confidence that the last bit of air has left the radiator - thank you!

Now I just have to worry about the fan viscous coupling failing (if it hasn't done so already)
...and the temperature gauge being a lying little towrag.

But with the bonnet open and the engine ticking over like a Swiss watch, it's nice and drafty in there, and the aircon clutch clicking solidly in and out. And the sun shining. What's not to like!

The viscous fan should roar on startup and then go quiet after a minute or so as it warms up. At this stage it should be possible to stop it with a rolled up newspaper. As the temperature climbs it will start to make a noise again as it locks up and at this stage it will shred the newspaper. It works pretty well and doesn't fail from getting wet, like when wading, although go too deep and the fan blades can snap off and ding the rad if it it is locked up at the time.
 
Thinking of fitting an electric fan anyway - anyone got an opinion on the Revotec kit?
I had one on my DSE I think I was an early customer as they sent a fan that was too deep and it wouldn't fit between the radiator and the front pully on the engine. Once I had the correct fan it all worked fairly well. But as @Datatek says his modification is quite a bit cheaper to do. I suppose it's horses for courses as with any mod.
 
The viscous fan should roar on startup and then go quiet after a minute or so as it warms up. At this stage it should be possible to stop it with a rolled up newspaper. As the temperature climbs it will start to make a noise again as it locks up and at this stage it will shred the newspaper. It works pretty well and doesn't fail from getting wet, like when wading, although go too deep and the fan blades can snap off and ding the rad if it it is locked up at the time.
Interesting tests. My fan doesn't do any of that - when cold it is pretty easy to rotate the blades by hand. From what you say, when cold it should be pretty difficult to turn.
Time for a new (Febi Bilstein) coupling methinks...
 
Get yourself a cheap obd bluetooth elm237 thingummy
There seems to be a bewildering choice of these devices at a very wide range of prices, and an equally wide range of the software that you need to run on your phone to read them.
Any recommendations to suit my 1997 4.0SE?
 
Old radiator cap as spare, with new viton o-rings fitted. Old rings were worn and hard. Sizes: 3.5mm thickness x 34mm ID and 35mm ID.
Top seal was OK, not changed.

Radiator cap new o rings July 2023.jpg
 
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There seems to be a bewildering choice of these devices at a very wide range of prices, and an equally wide range of the software that you need to run on your phone to read them.
Any recommendations to suit my 1997 4.0SE?
I'd go cheap and cheerful eg

But you have to make sure it works without errors as there's a lot of fake junk out there

The torque app will give you a status, if it's working properly
 
The tightly rolled newspaper test for the viscous fan is the one that matters. Engine up to temperature, insert rolled newspaper into fan blades, if it stops it's NBG.
 
For my Classic V8 I just buy blue concentrate & dilute as applicable (50%)

The only ready-mixed solution I buy is Halfords screen wash, because I could never remember how much water or screen-wash to add when topping up :oops:
 

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