10 replies to this topic

[Tifferrobinson]

Mini City E
1992:


My mini doesn't really seem to warm up - the needle gets to midway between the blue and the middle white line and that is where it stays. Now I know that it is cold at the moment and the guages aren't an exact science, but I am seriously considering buying an 88C thermostat and fitting it instead (I'm assuming my current one is cooler than that but I don't know) - it will only cost a tenner or so but will be a bit of hassle (draining coolant etc) and if it ends up that I'm damaging my motor or it makes no difference I'll be annoyed. The heater does seem to warm up although not tremendously well - just well enough to demist after 5-10 minutes driving. My petrol consumption is right down at 6.5 miles a litre (pretty pants) which could be due to the engine never warming up fully. Could the thermostat be stuck open, is this how the guage would behave if so? Thanks for the info in advance.

[rozzer1275]

when my 96 mini was standard with a 88 sat, the temp gauge sat spot on halfway, sats can get stuck open as they get old.

[Ethel]

You don't need to drain the radiator to change a thermostat. Though may be worth doing if the Antifreeze is likely to be a couple of years old and a good flushing through may improve the heater. Thermostats aren't that different to have a huge effect on the heater temp and will make no difference whatsoever as the engine warms up.

[Tifferrobinson]

You don't need to drain the radiator to change a thermostat. Though may be worth doing if the Antifreeze is likely to be a couple of years old and a good flushing through may improve the heater. Thermostats aren't that different to have a huge effect on the heater temp and will make no difference whatsoever as the engine warms up.

Don't you? The haynes manual says you have to drain a bit of it at least. Antifreeze is about a month old. What do you mean it will make no difference - surely the engine will be allowed to get to a warmer temperature (therefore better fuel consumption etc)

[Ethel]

It will help fuel consumption once the engine has warmed up (suspect it will already be an 88) the engine will warm at the same rate until the stat opens - think of it as a temp operated switch. You'd lose a little coolant unbolting the stat housing but no more than you're likely to spill fighting with the bottom hose.

[drMini]

I was just searching around for this exact problem - only my issue is slightly more complicated - I was going to try the thermostat first.

I recently baught an 88 mini (998cc Designer) and have been running it about 90 miles a day on the motorway for just over a month. This is the first classic car I've driven on a daily basis but I have nearly completed a complete restoration of a 68 Triumph Vitesse. When I baught it I did the usual servicing etc. because of the expected high mileage and just to be sure (oil + air filter, points, rocker gaps, new oil etc.). It was doing around 45 MPG on average.

Last week I started seeing steam out the exhaust so took it off the road immediately and changed the Head Gasket - it had corroded between cylinders 2 and 3. I then put it all together and reset the timing to 8 degrees BTDC as per the manual. Is that right for running it on unleaded? When I put the head back together I had a good clean out, took a load of carbon off the valves and reseated them, and the exhaust valves hadn't receeded at all - it's been run on unleaded without additives at least by the previous owner for 5 years.

I reset the rocker gaps and timed it all up again, with the assumption that the mixture probably shouldn't change because I hadn't touched anything to do with the carborettor.

Since then it's been running cold and I've needed the choke out two stops to get any kind of accelleration - it feels like it slows down when you depress the excellerator if the choke is in. Needless to say it's only running at 30 MPG.My thoughts were:

Is it the thermostat? It was a bit cold before but perhaps the timing was off before and it was warming up plenty. By the time I get on the motorway for a few miles though it should be fully open and the engine plenty warm enough.

Is it the timing? - that's the one thing I really changed and I could have got it wrong, I don't have a tachometer but it seemed to be around 8 BTDC at a range of slow speeds without the vacuum advance connection in. Shouldn't it be different when using a different fuel - I can't seem to find this topic around.

Or is it the mixture - after all pulling the choke out fixes the problem in the short term - though that would mean it's running too lean and I'd have to put more fuel in - not something that's going to reduce fuel efficiency too much, right?

Maybe I have missed something in putting the head back together?

As you can see I'm at a loss - I baught a mini to be an affordable efficient car - and it's running the same as my old 2 tonne volvo.

[Ethel]

It's always worthwhile marking across the dizzy & block so you can return it to the previous setting. I'd check the ignition system over first. You can pick up multimeters with a tachometer and dwell meter fairly cheap - well worth having with a contact braker equipped dizzy.

[blacktulip]

any joy anyone? mine is the same at the mo, after a new stat though.

[ZED]

My car is the same, never even gets to the halfway mark.
the heater is ok, demists the windows and on a really cold day you can feel the heat in the car.

but let us see good in bad, at least it wont over heat! coolant everywhere, split hoses, left on the side of the road for hours waiting for recovery, everyone going pass giving you sympathetic eye

Z

[Ethel]

The gauge is less accurate than the thermostat (which you can check with a saucepan 'n thermometer), wherever it reaches and stays steady will indicate the thermostat is operating. It's only if the gauge moves from its usual spot once it's warmed up that you need to pay attention.

[Tifferrobinson]

The gauge is less accurate than the thermostat (which you can check with a saucepan 'n thermometer), wherever it reaches and stays steady will indicate the thermostat is operating. It's only if the gauge moves from its usual spot once it's warmed up that you need to pay attention.

I can see I'm gonna have to get it out and have a look - I don't even have a thermometer!