Overheated on shut-down - ignition light on - help!!

[OldEnglish68]

Hi All

Please share knowledge if you can help me - all very gratefully received!

My car (S3 V12) has run perfectly for the last few hundred miles. Including hours stuck in traffic on hot days.

My out journey today was about 25 miles, with one stop. All fine.

Before setting-off for my return, I tried the lights (thought I should check as I had not used them yet...)

At the start of my journey I noticed the ignition light was on but faded away as revs went up.

I pulled over half way home, leaving the engine running while I took pictures of the speedo (hit 100,000 miles today!) and noticed temperature slightly above normal but thought nothing of it - especially as it went down once driving again (assumed fans had kicked-in)

Drove home and left car running while opening garage doors (bit of a procedure involved there!) in case battery flattened.

Backed into garage, switched off and was greeted by burbling and spewing of lots of nice clean coolant from overflow.

Put ignition back on (engine off) and no fans running but gauge showed v hot.

Questions (panic, actually!) in my head are:

a) Permanent damage?

b) Fans don't work if alternator faulty?

c) short/blown fuse somewhere?

d) Switching-on lights caused short and now fans don't work? (lights work fine though)

e) Something else?

f) OK to re-fill and drive to workshop or automatically a job for a recovery truck?

g) Why do these always happen at the weekend?

NB: 'g' is the only question I have an answer to...

Please advise on best next step...

Thank you and best wishes to all.

OE68

[piman]

Hello OE68,

I won't bother going down the itemised list as most are irrelevant.

The first thing to do is to refill the coolant and start from there. Have a check on the drive belt, I am not familiar with the V12 but assume the water pump and alternator belt are the same belt?
It's possible the loss of coolant meant that the fan sensor is now in air which, usually, means it doesn't sense and hence the fans won't run.

Start simply and let us know what happens?

Alec

[PPV]

Hi, no experience of the V12 but don't panic. I agree with Alec, start from scratch now cooled down. Check belts etc are as normal. Fill up with water and check for leaks before starting, start up and let it warm up keeping eye on gauge and engine for leaks and go from there, watching for insatnce if fans operate as expected.
I am sure that with some facts then there will be plenty of advice as to what to do. Let us know what happens.
Regards,

[OldEnglish68]

Thank you!!

Panic subsiding a little now...

Fingers crossed so tightly even typing this is tricky!

Needs to be fit again for round Britain trip (one leg only) so I'd better get it sorted.

Thanks again


OE68

[OldEnglish68]

All sorted, thanks to Birks Motorsport.

Two separate faults - bad connection on regulator meant ignition light on though it was charging fine.

Failed after-market fan switch faulty. No fans = high temp!

[PPV]

Glad it is all sorted.
Regards,

[OldEnglish68]

Thank you.

Happily using the car for commute to work at the moment-very pleasant indeed!

Thanks to piman too, for calming advice. It worked.

All the best


OE68