Now sorted - the age old problem of coolant replacement

[Blokko]

*arrowup*Yep, but SWMBO being a bit precious about her pots an pans + lack of thermometer put me off that one 😬 Besides, in the time it took for the water to cool down I was able to get to Halfrauds and back with a new 'stat in hand - and given that a replacement was only £6.50 I was prepared to change it without having proof that the old one was kaput.

[charlie_pank]

I always want to keep going until I prove the part is faulty rather than stopping when the symptoms disappear. How about boiling the kettle, print it into a garage container that won't melt and dropping in the thermostat before it cools down?

[Blokko]

Didn't think of that method Charlie

 

My mate Phil has the old unit and will be testing it out - today I guess.

 

What I'm expecting / hoping is that the test will show that the unit does not move until 90c+ and then springs partially open. That would fit in with what we were seeing as we warmed the car.

 

Anyhow, the rain has stopped (albeit temporarily, I'm sure) so I need to get out on the road to make sure everything is working correctly......

 

 

[Roadsport06]

What temp thermostat did you opt for? When mine went I brought a 82 degree one as the fan switch kicks in about 86 degrees (from memory)

[Blokko]

Went out for a run of about 80 mins in mixed traffic conditions and the temp remained rock solid at just over 80 degrees.

 

Word from Phil is that the old thermostat does not move until near boiling and even then it only opened 2-3mm. So I think it is conclusive that the thermostat was the issue!

 

I went for an 82c thermostat – which is the the same as the one I took out. I'd say the fan kicks in just shy of 90.

 

Lessons learnt -

 

- Coincidences do sometimes occur – I was convinced that the problem was solely to do with an airlock and so assumed that everything else was ok (including the thermostat)

 

- Just because the thermostat is opening, it doesn't follow that it is opening fully or at the right temperature. Again, as the bottom hoses / bottom of the rad were getting hot I concentrated on an airlock that didn't exist rather than the stat.

 

- I assumed that a new stat would be expensive and possibly a special order. Knowing now that it is a Rover bit that is available from any motor factors for less than 7 quid and that it is relatively easy to change, I'd be much quicker to to swap a stat out (or at least test it as per Charlies' instructions) if I came across a similar issue in the future.

 

 

I can now pack the car away for winter knowing that I'll be ready to get straight back on the road when the car comes out of hibernation in April

[Wrightpayne]

Talk of using SWMBOs saucepans reminds me of Dave Jackson using the dishwasher for cleaning his K cylinder head 😳

 

Ian

[Mort]

What does the jury consider to be the symptoms of a dodgy thermostat in a K-series? Mine runs at a constant 80 degrees C - although it may go up a little until the fan cuts in - ususally in traffic - then it goes back down again, so all seems OK. However, the bottom hose from the radiator to the thermostat never gets so hot that I can't keep my hand on it, although the top hoses are much warmer. Is this just a sysmptom of a 1.4K being over-cooled?

 

Edited by - Mort on 26 Nov 2012 18:09:09

[John Vine]

Quoting Mort: 

However, the bottom hose from the radiator to the therostat never gets so hot that I can't keep my hand on it, although the top hoses are much warmer. Is this just a sysmptom of a 1.4K being over-cooled?

I'd say that was entirely normal, and simply the result of hot coolant being cooled effectively by the rad.

 

JV

[Mort]

Thanks John. I was rather hoping that might be the case.