[mk1] Running temp

[Jon Bradley]

Ok those of you who read my post a while back about my car running colder on the motorway... I replaced the thermostat and problem solved...

But now i've only just noticed (though it could have been doing it ever since i changed the thermostat) that the temp gauge steadily increases up to about 80% of normal operating temp...and then hangs there for quite a while, then veeery slowly creeps up to just below normal operating temp. While its doing that if boot it (may be speed related or could be water pump rpm related) then I see the temp gauge dip back down to about 80% again.......It finally heats up to normal temp and the needle stays put bang in the centre of the dial.

Anyone got any ideas what can be causing this.... Could air in the system cause this problem? I havent got round to trying to bleeding it yet.

Cheers, Jon.

[PW@Woodsport]

could be just the extremely cold temps we have at the moment jon blasting icy cold wind into your rad when you boot it,that would probably explain whats going on,i could be wrong of course.

[spudgun]

Wouldn't worry to much if its running a bit colder than normal. When it overheats you have a problem on your hands.

[Lauren]

Sounds pretty normal to me tbh. The thermostat can only react so quickly.

[Jon Bradley]

oh good. its my first winter with my this car so wasnt sure! thanks everyone

[raptor95GTS]

if the temp gauge is moving that quick when you boot it I'd check the coolant and bleed the whole system. The temperature should not vary that much that quickly just booting it.

only my opinion but if it was my car....

[James_Ward]

I agree with Alan.

My temp gauge goes right up to the middle and stays there rain, shine, cold or very cold, if it were my car I'd check it out...... doesn't cost much to flush your coolant and replace, check the filler cap seal etc. but a changing the head gasket costs loads!

[raptor95GTS]

drove to work today and my temp didn't rise past 1/4 mark. Looks like my thermostat has gone the way of the dodo.

That'll teach me to comment here!

[crazylegs]

I wouldn`t worry ,if it stays down you are ok.I have a mk1 that sits just over half way and also another(which is for sale) which never even gets to the half way mark.Stays around a third even after sitting running for half an hour.The sensors vary so unless it is getting v.hot just give it a bleed and top up the antifreeze.

[Lauren]

Like Crazylegs says you have to allow for a little bit of variation between cars, so don't worry unneccesarily.

[vashy]

Hey Jon, I wouldn't worry either, in fact mine behaves very similarly to your original description! Mine sometimes dives quite dramatically, the first time I boot it after warming the engine up. More so in this cold weather.

[reggie]

The only problem with a permanently open thermostat is that the engine doesn't warm up fully. This would cause the choke to remain on and therefore will use more petrol and lose a bit of performance.

[jimi]

I had the same problem with mine last week, slow to warm up, gauge diving when I booted it. Fitted a new thermostat(MR T) and it stays rock solid all the time now.
hth
Jimi