Hot handbrake on hot days around town

[Siv]

Hii I have just had my radiator replaced following a sudden expulsion of coolant. Mechanic has bled system according to 'fury protocol'
I now notice (feeling jittery and noticing everything now so unsure if this happened before) the base of the handbrake gets hot on a hot day driving round town (UK) but is stone cold on a long motorway run.

Is this normal or should I start paying out for diagnostics just in case?

My first savings spend will be to get a coolant/temp alarm fitted, maybe next month! (Thx to radiator and new battery)

[g8dhe]

Because of the shape of the engine housing, the hot air around the engine rises to the top ... just under the handbrake. However there is a sensor for just this purpose and if it gets too hot then the Scavenger fan will blow air thru cooling it down. On a longer faster drive there is sufficient cool air ducted up over the engine by the under tray.
So other than checking to make sure no carpet has been caught under the seats and letting hot air out from the engine housing into he cabin, is pretty normal.

[Siv]

Thank you so much for your response. I'm at the 'analysing everything' stage and worrying whereas I'd like to return to enjoying my Bongo carefree

To double double check, this is the order of events:
Uneventful journey from Exmouth to Kent and back over a weekend (EXCEPT I did notice the fridge ended up hot inside, as its relatively new and the fridge wasn't working (now sorted) it didn't raise any alarm bells) then the next day I was sitting in blistering heat at the local services waiting for someone for 10-15 mins with engine idling (2.5 diesel automatic), we all noticed a funny smell (now known to be hot coolant) once I'd switched the engine off out came the whole lot of coolant and radiator split at top.

Now one new radiator later and we are back to my original post ... nervously feeling optimistic but noticing everything ....

[g8dhe]

Have you checked that the radiator fans are coming on when stationery once the coolant has warmed up ? They have two speeds slow and fast which will come in at increasing temperatures. Then as mentioned above the scavenger fan which is mounted directly in-front of the engine comes on once the engine housing gets to around 85°C to keep the air flowing around the outside of the engine.

[Siv]

Thank you, I have previously heard the normal fan, will listen out for speed. Not sure I've ever heard the scavenging fan (may be an issue) is it quite audible and obvious?

[mikeonb4c]

Thank you, I have previously heard the normal fan, will listen out for speed. Not sure I've ever heard the scavenging fan (may be an issue) is it quite audible and obvious?

It is once you've heard it, but until you've heard it you might not distinguish it from the radiator fans (though by looking into the engine bay you can see if it is operating. You can test it either by using a hot airgun to heat the air around the sensor that sits at the top of the engine bay behind the handbrake (visible with the wires going to it when you lift the engine covers) but obviusly you need to be careful not to scorch the surrounding area if doing that (though I did it last week with no bother and the fan duly came on. You can also test it by shorting out the switch with a piece of wire across the relevant connector terminals. This doesn't test the sensor of course, and when I did a few times the fan came on and stayed on even with the ignition off so I think there might be an ECU timer involved so it stays on for a while after engine stop if the sensor has been activated more than once.

[Siv]

That's really helpful thank you, quite happy to tackle that confidently and safely (but won't fiddle with the wiring).i have today ordered a coolant and temp alarm so soon hopefully can breathe easily

[Gasy]

Now get them fitted ASAP
It's about a 1 hr job for each
Just shout if you need help

[Siv]

Thank you. When it's all fitted and I'm staring intermittently at the road I shall be contemplating my temps (thanks for providing your alarm norm). Could you think up some Fahrenheit/Celcius (whichever it uses) bandings for 'Cool as a cucumber'; 'Warm but not hot under the collar'; 'Damn it's getting hot and worrisome'; DEFCON4 Alert and Stop'?

[Gasy]

100c and time to start panicking
You will soon see what the normal running temp for yours is
Usually 82-90c
it's when it starts to rise above the normal running temp
That I start to watch it more than the road
And turning on htg and aircon
DONT stop and turn off engine
Unless you see steam and the low coolant alarm is going
I have a switch fitted to turn on the scavenger fan as a last resort
That scavenger fan soon knocks the temp back down and the switch is an easy enough modification to do
Do let us know what your usuall running temp is
The temp sensor is usually bolted under one of the rocker box cover AT THE REAR OF THE ENGINE

[mikeonb4c]

100c and time to start panicking
You will soon see what the normal running temp for yours is
Usually 82-90c
it's when it starts to rise above the normal running temp
That I start to watch it more than the road
And turning on htg and aircon
DONT stop and turn off engine
Unless you see steam and the low coolant alarm is going
I have a switch fitted to turn on the scavenger fan as a last resort
That scavenger fan soon knocks the temp back down and the switch is an easy enough modification to do
Do let us know what your usuall running temp is
The temp sensor is usually bolted under one of the rocker box cover AT THE REAR OF THE ENGINE

Thanks for those figures Gasy - very useful. Just recently fitted the TM2 I bought a while back, sensor bolted to the near side rear rocker cover bolt. After I've stopped from a 15 min drive to work, I'm getting around 82c, which seems to fit with your figures. I've had a scavenger over-ride fitted for some while (mine uses a separate power feed to the fan switched via a relay as no-one knew any better way when I fitted mine - seems to work ok). I tried switching it on when stationary but with engine running after returning from work and was impressed how effective it was at dropping the TM2 temp reading, albeit that the sensor is measuring temperature at the surface. Very reassuring though, for the day when I'm doing a hot mountain climb

[Gasy]

Yes I did wonder with the scavenger dropping it so quick
If it was just the surface temp / air flow over the sensor
But I only use mine for a min or a few mins at max
And when I switch the scavenger off
The temp does not rise again
So it must be cooling the engine core temp aswell / letting the heat dissipate quicker
Or something like that

[Siv]

Thank you so much, I'll keep note of these and make a note of mine. Will fit both together as soon as they arrive (coolant alarm here already)

[mikeonb4c]

Yes I did wonder with the scavenger dropping it so quick
If it was just the surface temp / air flow over the sensor
But I only use mine for a min or a few mins at max
And when I switch the scavenger off
The temp does not rise again
So it must be cooling the engine core temp aswell / letting the heat dissipate quicker
Or something like that

Absolutely. Whats happening at the surface must ultimately be reflected at the core. I'm guessing that the driver can get to know from observation of their TM device what conditions may lead to core heating and opt to put the scavenger fan on before the the engine starts generating extra heat, rather than after it has.

[Gasy]

Yes with the extra out puts from the engine temp sensor
I can set it to bring on the scavenger fan at a temp setting of my choice
I have always planned to do this so the scavenger comes on at engine head temp of 90c
But as always it's time

And then I like to watch me engine temp now
I like to know how hard the engine is having to work
And you can really see the temp changes
I'm going to put one on me gear box oil one day
But as always it's time