Weird coolant behaviour......S1 K series...
Discussion
I have just returned from 10 days blasting around Europe....and this did indeed mean many hours of non stop 80mph+ for most of the days, including a traffic jam from hell yesterday before the Hoek Van Holland ferry, where the car was in and out of the fan temps for over an hour.
Passport control at Harwich was just as bad, took ages and the car hit fan cut in temps.
On day 3 of the trip I noticed the coolant was way below minimum, even on cold. I could only top up with tap water alone.
As was swell but this morning ( a week later) and the level is very low again, much lower than its normal 'close to the min line'.
What should I check first? Apart from leaks, the cap??
Worried, naturally, that this may be the first signs of HGF.....
Passport control at Harwich was just as bad, took ages and the car hit fan cut in temps.
On day 3 of the trip I noticed the coolant was way below minimum, even on cold. I could only top up with tap water alone.
As was swell but this morning ( a week later) and the level is very low again, much lower than its normal 'close to the min line'.
What should I check first? Apart from leaks, the cap??
Worried, naturally, that this may be the first signs of HGF.....
If it is definitely losing water, then (for what they cost) it is worth changing the cap (and checking for leaks - does the car smell of coolant at any time?).
But are you certain it is actually losing water below the minimum mark? I think most K series Elises run at or below minimum, and topping them up when cold just forces excess coolant out. I would be tempted to not add any more water, then continue to monitor the level (and temperature!) closely, and see how it goes.
Mike…
But are you certain it is actually losing water below the minimum mark? I think most K series Elises run at or below minimum, and topping them up when cold just forces excess coolant out. I would be tempted to not add any more water, then continue to monitor the level (and temperature!) closely, and see how it goes.
Mike…
Personally I would top the coolant tank up to half way between the minimum and maximum levels with proper coolant (not water) and monitor the level after every journey. It will dump any excess coolant and should hover just below the minimum line. However in the past the coolant level in my S1 disappeared for a few days and then reappeared!
There shouldn't be any problems with constant 80mph+ and the occasional stop for hours in heavy traffic - That's what the fans are for
Keep an eye on the level and temperature for the next month. It might be worth checking for any puddles of coolant on your driveway or mayo appearing in the coolant tank cap.
There shouldn't be any problems with constant 80mph+ and the occasional stop for hours in heavy traffic - That's what the fans are for

Keep an eye on the level and temperature for the next month. It might be worth checking for any puddles of coolant on your driveway or mayo appearing in the coolant tank cap.
I've had my S1 for just over a year and it was back to the dealers for 4 pressure tests in the first month as, like you, the coolant level in the expansion tank was about 2cm. If I topped it up it disappeared! The mechanic said that it finds its own level and after 12 months of daily driving in all sorts of conditions it has never over-heated and is absolutely fine so I have stopped worrying.
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