Gears & Running Temperature

[rsawatson]

Two questions...

I've started to notice, particularly when edging forward in a traffic jam or when reversing backwards slowly into a parking space, when the clutch is lifted up the gear does not properly disengage - it can sometimes keep going - unless I physically take the gearstick out of gear. Is this a simple problem to rectify - i.e. does the clutch need adjusting? If so, I'd appreciate some advice on this - as I've never touched the clutch before.

Secondly, what is an okay running temperature in hot conditions like this? Say, in traffic jams or when cruising at 70mph. I was concerned that my engine was running hot (temp was half way in between 90 and 140 Celsius when driving on dual carriageway).

Thanks,

Ryan

[AntB]

my experience of an increase in running temperature in ALL the cars i've owned is that it is the pre-cursor to something needing replacing, either a hose, or a rad etc.

is your rad staying full?

[rsawatson]

Yes the radiator is staying full - I think to be honest that the alarm bells went off in my head purely because of the fact that the running temperature is so dramatically higher than it was when I last had the car out a few weeks ago in much milder conditions. I think I'm to assume it's normal in light of the hot weather.

[AntB]

may just be something to keep an eye on then

[Alec]

Hello Ryan,

are you saying your gauge registered 115 degrees C (I'm assuming Celcius and Centigrade are the same?)

I would suggest your gauge is not indicating correctly as that is far too hot?

Alec

[linearaudio]

Shouldn't get anywhere near that temperature! Thrashing Molly around all last (hot) summer well loaded and she sat at 80 degrees. Didn't even refit the fan until August, after she started creeping up to 90 in heavy traffic!
Temperature gauge was checked OK in a kettle of boiling water, before her Ladyship was awake one morning!

[rsawatson]

Thanks for suggestions so far.

It may well be that the gauge is reading incorrectly - although don't understand why it would be all of a sudden? And yes I did mean Centigrade.

I will double check the coolant level tomorrow - as it does concern me!

Cheers,

Ryan

[linearaudio]

If your temperature sender is like mine, then you can easily unscrew the retaining ring and remove from the holder in the engine block without any fluid loss. Whilst I obviously don't advocate using your better halfs kettle under the bonnet, on an extension lead....ahemm..But if you happen to be within a quick dash of the cooker, a saucepan of boiling water will only drop to about 95-97 in a couple of minutes, accurate enough to judge if your gauge is anywhere near right!

[bmcecosse]

Certainly that's far too hot - if it really IS at that temperature - then the engine will be 'cooked' in no time. I would urgently change the thermostat for a known good one - a 74 degree for summer if possible. At the same time - flush the rad back and forth - and then try again! Just a thought - is the temp gauge electric - and is it fed through the voltage regulator ok ??
As for the clutch - how much free travel do you have at the pedal ?

[rsawatson]

I will hold off using the car for the moment whilst I check it out. I think I have a thermostat in my spares box so may change the coolant and replace the thermostat at the same time.

The gauge is wired via the voltage stabiliser on the back of the speedo.

Cheers,

Ryan

[bmcecosse]

Oh well - flush and stat it is !

[rsawatson]

I changed the thermostat yesterday afternoon (it's an 82 celsius). However, it did not seem to make much difference to the running temperature, so I am presuming that it is most probably a problem to do with the radiator. It should not be the water pump as I replaced this last year.

I gave the car a good run yesterday afternoon - firstly, I left it on the driveway to get up to running temperature with the choke very slightly out so as to just open the throttle - it seemed to sit at just above 90 degrees. I then took it for a run, and rather than cooling down as I got faster like it usually does the temperature rose, until it sat just below the mark in between 90 and 140 degrees.

I have done 15k miles in my car over the last year, including a fair amount of motorway driving. Would the radiator therefore benefit from a good blast out in order to improve air flow and therefore heat exchange, as it looks as though there are quite a lot of dead flies and other debris in between the fins? Would the fact that all hoses are hot and reaching the same temperature allude to the conclusion that the coolant itself is making its way round the system?

[Alec]

Hello Ryan,

the more I read the more I believe your temperature gauge is calibrated in Fahrenheit, and 115degrees in Fahrenheit is about 45 degrees C, perhaps a little cool but Minors (with a serviceable cooling system) do tend to run cool.

My reasoning is if that was a Centigrade temperature it would have boiled and dumped all the water, also cars with severe heating problems tend to get hotter and hotter until boiling and dumping their water rather than staying at an implausible 115 degrees.

Alec

[linearaudio]

The obvious question to verify that is- what does the gauge read up to on its scale?
Just checked mine- that reads up to 120 centigrade, which is itself up into the "annealing oil control rings" area of overheating!(how did I find that out? )

[PSL184]

Could just be that the sensor has gone faulty - Try another one and see.....?

[AntB]

open the drain tap on the radiator, empty it, and then refill it watching to see how quickly the water runs through? basically give it a flush.

a car which is overheating doing high speed work isn't getting cooled by its rad quick enough imo

[alex_holden]

Would the fact that all hoses are hot and reaching the same temperature allude to the conclusion that the coolant itself is making its way round the system?

That's not a good sign - if the radiator was working properly the bottom hose would be cooler than the top one while the engine is running.

[bmcecosse]

Could also be a sign of poor circulation - due to rotted out water pump impeller..........

[rsawatson]

I tend to agree with the suggestion that perhaps it is the temperature gauge that is to blame. I had a good look at the radiator, and I could see straight through it into the engine bay - so no problem there. Even when the gauge was reading 115 degrees C, when I unscrewed the radiator cap the water did not boil - which of course it would do if it really was at that temperature.

I'll borrow a thermometer from university to test the sensor, and check if they marry up. Hopefully they won't as I'd rather have to buy a new sensor than have the trouble of sorting out an overheating problem! Would it be a reliable test to stick the thermometer into the top of the radiator or do you think I'd need to actually take the sensor out, and say test it in a saucepan?

Cheers.

[Alec]

Hello RS,

the usual radiator problem is not blocked fins externally but internally, silt clogging the radiator tubes and setting hard, thus the water doesn't flow properly through the core. At least you seem to have now realised that the temperature indication was not sensible, There is no problem with dipping a thermometer into the radiator neck to measure the water temperature, with care of course

Alec