New coolant temp sensor

New parts arrived - a couple of thermostats at original 92ºC and 88ºC and ECU coolant temp sensor.

Standard 54mm/2" thermostat, drilled with a 4mm bypass hole to allow circulation before it opens - I thought I'd replace this anyway while the housing was open.

Confirming the failure point

Next up comparing the temp sensors, the new one is from Emerald however took a few minutes to double check before replacing. The part number is E450 on both, I think the 4011 and 0418 on the reverse must be manufacture dates - week number and year.

The old sensor read approx 9k ohms and the new one - in a similar room temp environment only 3k ohms. They drop resistance as temp rises so that would be consistent with the old one thinking the engine was colder than reality and therefore not turning on the radiator fan.

Double checked in the ECU software - the old sensor (left) thinks the ambient temp in the garage is 4ºC below and goes up to around 70ºC max. The new showing a much more sensible number - QED - sensor failure but within range so the ECU just wasn't turning on the radiator fan.

While I was here I checked no sensor connected - at which point the ECU reports 80ºC but also turns on the radiator fan.

Reassembly

A little fiddly to get the ECU sensor in under the dash one - requires removing both of them - but relatively straightforward.

Thermostat

I'm going to try a slightly lower thermostat value to let coolant into the radiator a little earlier at 88ºC which should let the radiator smooth the top of the warmup curve before the fan has to kick in 10ºC later. Should help things when the car is stationary and hopefully doesn't affect things significantly when moving airflow is present.

(Horizontal scale here doesn't mean anything - its just representative, Yellow where coolant is admitted to the radiator, and green the fan kicking in.)

Thermostat back in its home.

That was good - nice clear failure component identified, hopefully the new one lasts another 7 years.

Option/thought - there is a thermostat mounting point in my radiator - would just need a radiator mounted switch which grounds the lead on ECU Pin6 (or the other end of it on the fan relay).

Cooling system - maintenance

On the way back from Norway the car decided to chuck out all its coolant and peg the temp gauge at best part of 130ºC. After letting it cool and topping up the coolant everything was fine - but it was a particularly cold night coming back - so possibly just got away with it due to forward motion?

Today I let the car run at idle, part of its static monthly exercise, running up to full water temp and letting the oil circulate.... the coolant gauge again jumped up over max temp and on switch off blew the bulk of its coolant out of the overflow onto the garage floor.

Something then is still not right.

I wasn't really watching it so not sure if the radiator fan cut in when the engine was running.

Tests so far

Confirmed the ECU is seeing a temp reading - check

Used the ECU software to check the ECU could turn the radiator fan on - check

Swapped the fan relay with the aux panel one to confirm identical behaviour - check

Removed the thermostat and checked it opened around nominal 91ºC - check

Next up, monitor the ECU temp reading and see if its seeing the coolant temp rising and see if the fan relay keeps flipping - not sure if that is because the battery is low due to the car not running?

...

Update - sensor replaced issue fixed.

Heater upgrade - 2

Air box for the new fan progressing...

Taken from the paper template then adjusted for even gaps top/bottom to accept rubber trim.

While everyting is in bits, the tunnel heater vents are changing too - rectangular peg into a round hole - but will mean I can reach them when buckled into the seatbelts.

The small cover panel will be at least blacked out and possibly carpeted so shouldn't notice once complete.

That should do the trick.

New ducts, the new vents need 55mm rather than the existing 50mm.

The important bit - just reachable from the seated/belted position.

Heater upgrade - 1

Finally got around to some car work. 

Upgrading the existing heater fan to a squirrel cage from the original axial fan. The axial fan moves air - but can't generate significant pressure - I'm hoping the new fan will improve on that without tipping me over my current budget.

The space I have to work with. The heater radiator hoses will stay outside the air box.

Mocked up the new bracket and airbox to draw fresh air in from above, through the bonnet vents with offset more space on the drivers side where the fan intake will be.

Starting with the fan bracket, 1mm aluminium but seems sturdy enough once the panel has flanges added.

Offered up - looks ok so far.

Some challenges with fouling the pedal box lid bolts - might be as simple as a shortened bolt in the back position.

It's a 3 speed fan - I'm intending just to have one setting - On or Off - no point in finesse of air speed in an open top Zero + avoids any changes to the dashboard controls.

Air box surrounding the lot to follow.

Lysebotn Preview

I really must get around to recording the tail end of the Norway trip including down the side of Lysebotn Fjord.

Underground hairpin

 

More to come.

Heroes of Telemark - Mael and Vemork

The Heroes of Telemark, a great movie based on a true story, Richard Harris, Kirk Douglas - whats not to like. A real adventure with the later scenes based around sabotaging the Ferry which carried heavy water from Mael station to Tinnoset.

A visit to Norway was always going to include Mael and seeing where the Heavy water plant was, this was my must visit location. Of course there's nothing there now from the real events or the movies but perhaps echos of the past somehow recorded in the place.

From Gaustatopen the weather opened up for the drive down the valley, fast straights and hairpins now with the road virtually to myself.

Nothing in the boulder catch nets above us.

At the valley floor a right turn with the railway line, the line that had originally transported materials from Vemork to Mael to be loaded on the ferrys.

Mael Station

There is a train which still runs, but I'm more interested in the train ferrys.

The place apparently is also the first location that had a standard gauge railway - if I remember correctly.

This is the location. In the movie I seem to recall the local school is loaded onto the ferry just after Richard Harris booby trapped it with the intention of sinking the shipment of heavy water, It's a long time since I've seen it though - I recall there is some ruse about practicing evacuation on deck so the kids can be rescued...   

I've also no idea how close the film is to real events.

Signal box... life size train sets, perfect!

Vemork - Heavy water plant location

Headed west along the valley, short stop in Rjukan for supplies - the typical ham/cheese and rolls to make a picnic, and we move off again, blue skies now and much warmer than the top of the mountain!

The road climbs up the north side of the valley, a couple of hairpins, I'm concentrating on the drive but just before a tunnel to my left theres something I immediately recognise.

The back of my neck tingles when I see these places in real life, the pipes down the mountain carrying the water and generating the electricity which was needed for heavy water production. I believe it's a different building now - but... best part of 80 years ago local resistance were on a mission to sabotage this place and disrupt the German production of an atomic bomb.

The sign describing the route the saboteurs took.

More top heavy barns...  but why? Anne thought she saw one with wheels too.