Midget 1500 - running a bit warm?
Discussion
My newly MoT`d 1979 Midget 1500 is on the road , and very nice it is too , runs very sweetly and handles well etc . After about 8 miles , the temperature gauge reads well to the Hot end but doesn`t overheat . Reducing the speed to 50 mph from 60 results in the temperature dropping .The car doesn`t actually overheat when standing and I`m just checking that this is a thermostat issue rather than anything else . The fan belt seems to be tensioned correctly and the car has covered virtually no miles in the last 3 years , so may be a bit tight .
Having said that the car is a hoot - and has attracted more positive attention than anything else I`ve owned .
Thanks , Mickyveloce
Having said that the car is a hoot - and has attracted more positive attention than anything else I`ve owned .
Thanks , Mickyveloce
Could be many things but don't just ignore it
You're brave taking a classic that's hardly moved for 3 years and driving it at 60
My suggestions,
check the rad is not blocked with debris from the road or leaking
check INSIDE radiator for coolant level (hopefully it's not just water but coolant mix and is not at a low level)
check it's not a head gasket failure (you can get a Frost testing kit) also look at oil cap for milky glup
check bottom hose to see that it hasn't colapsed (as quick as possible after 60 mph run)
check quality and oil level
Then you've got brakes binding (a favourite on a car that sits still for three years), carb set-up, blocked rad or waterways, fan belt resticted by alternator/water pump, water pump tired/blocked etc.
Never accept what has been done by previous owner as being actually done or done correctly - I have a FULL & PROPER 36,000-mile service (buy a Owners Handbook) ASAP on any classic car I get - flushing through and changing things like brake fluid, coolant and oil
If your head gasket and hoses are OK (new hoses can only be trusted for 2-3 years) I'd empty out coolant and flush and back-flush engine, rad and heater matrix and replace hose set before refilling with 4-LIFE (from MGOC) as part of the 36,000 mile overhaul
Hopefully others will be along soon with more and better suggestions
Let us know how you get on
You're brave taking a classic that's hardly moved for 3 years and driving it at 60
My suggestions,
check the rad is not blocked with debris from the road or leaking
check INSIDE radiator for coolant level (hopefully it's not just water but coolant mix and is not at a low level)
check it's not a head gasket failure (you can get a Frost testing kit) also look at oil cap for milky glup
check bottom hose to see that it hasn't colapsed (as quick as possible after 60 mph run)
check quality and oil level
Then you've got brakes binding (a favourite on a car that sits still for three years), carb set-up, blocked rad or waterways, fan belt resticted by alternator/water pump, water pump tired/blocked etc.
Never accept what has been done by previous owner as being actually done or done correctly - I have a FULL & PROPER 36,000-mile service (buy a Owners Handbook) ASAP on any classic car I get - flushing through and changing things like brake fluid, coolant and oil
If your head gasket and hoses are OK (new hoses can only be trusted for 2-3 years) I'd empty out coolant and flush and back-flush engine, rad and heater matrix and replace hose set before refilling with 4-LIFE (from MGOC) as part of the 36,000 mile overhaul
Hopefully others will be along soon with more and better suggestions
Let us know how you get on
Thanks for that ; a comprehensive reply .
To add a bit more , the car has fresh oil and water (antifreeze etc) and a full service prior to it going on the road . It`s also had new tyres etc etc and there`s nothing binding (brakes fine and new gearbox). The hoses are all good and the expansion tank has the same amount of fluid in it today as it did yesterday .
I think the fuel mixture is fine , so I`m looking for something I`ve missed . I`m ordering a thermostat tomorrow and won`t use the car until after I`ve fitted it .
All these considerations my Mercedes doesn`t need!
Love the car though .
To add a bit more , the car has fresh oil and water (antifreeze etc) and a full service prior to it going on the road . It`s also had new tyres etc etc and there`s nothing binding (brakes fine and new gearbox). The hoses are all good and the expansion tank has the same amount of fluid in it today as it did yesterday .
I think the fuel mixture is fine , so I`m looking for something I`ve missed . I`m ordering a thermostat tomorrow and won`t use the car until after I`ve fitted it .
All these considerations my Mercedes doesn`t need!
Love the car though .
mickyveloce said:
a full service prior to it going on the road .
check out a FULL 36,000 mile service - to some people an oil change is a full servicemickyveloce said:
. . .the expansion tank has the same amount of fluid in it today as it did yesterday .
Mickey I say again - check what's in the radiator, the amount of coolant and its colour and smell - more than once I've known a expansion/filler tank to remain level whilst the radiator empties, once when the pipe from it was blocked and the other time when the head gasket had failed! mickyveloce said:
I`m ordering a thermostat tomorrow and won`t use the car until after I`ve fitted it .
Fair enough but bear in mind with components nowadays you could be replacing a good component with a new one that isn't!For really full servicing get this book http://www.amazon.co.uk/Midget-Austin-Healey-Sprit...
I trust you've got a copy of this very, very useful Owners Handbook as it will tell you most of what you need to know as an owner - http://www.amazon.co.uk/MG-Owners-Handbook-Akm3229...
mickyveloce said:
Nigel , thanks again .
No problemmickyveloce said:
I`ve got two good books about the car
good but you must get - http://www.amazon.co.uk/MG-Owners-Handbook-Akm3229... (unless that's one of them)and for servicing http://www.amazon.co.uk/Midget-Austin-Healey-Sprit...
you might think I'm over the top about this but I'm now on my fourth classic MG and despite my previous knowledge and experience this one is more trouble than the previous three when it shouldn't have been!
mickyveloce said:
The coolant smells fine etc
Actually in the radiaror I trustmickyveloce said:
and the radiator is new within the last 1000 miles
good but remember you can get trouble from new componets too - oh yes, many times, many, mant times 
mickyveloce said:
and the hoses are sound .
the ones I replaced a year ago are holding but they don't look good crazed in under a year easily - wish they done a silicone set for the Midgetmickyveloce said:
We`ll wait and see !
don't worry you'll have good luck I've soaked up most of the bad in the last few weeks, let us know the result as I could learn from it, or re-remember it (to forget it later when it happens to me)The gauge should normally sit just below Normal, so the symptoms point to a cooling system that is running beyond capacity - the key to that statement tends to discount the sender or the gauge, as it is running well over normal temperature at a relativley slow speed, but drops when you back off.
The advice earlier is good and, based on what has been posted so far, irrespective of what has or has not been done to the car, it is not getting the flow of coolant that it needs. That means one of a few things:
Easy one first - take the thermostat out and check that it opening fully - and smoothly - by taking it out, putting it in a saucepan full of water, and bringing the water up to the boil. It should start opening before the water boils properly and be fully open when it is. Turn the heat off and watch it close - again it shold do so fully and smoothly. If it doesn't do so either way, or if the central stem is scored, then replace it with one that does.
More tricky ones - if the the thermostat works, then it is likely to be the radiator (notwithstanding that it might be newish) silted up or the water pump. Take the radiator to a radiatior specialist and check that it is the right sort of core for the car and that the flow rate is right - pressure testing just tells you that it isn't leaking, their flow test will tell you how efficient it is. At the same time (as you will have drained the coolant anyway) remove the water pump and check that the impeller is a) still there and b) that it does not turn independently of the shaft.
MG Mark
The advice earlier is good and, based on what has been posted so far, irrespective of what has or has not been done to the car, it is not getting the flow of coolant that it needs. That means one of a few things:
Easy one first - take the thermostat out and check that it opening fully - and smoothly - by taking it out, putting it in a saucepan full of water, and bringing the water up to the boil. It should start opening before the water boils properly and be fully open when it is. Turn the heat off and watch it close - again it shold do so fully and smoothly. If it doesn't do so either way, or if the central stem is scored, then replace it with one that does.
More tricky ones - if the the thermostat works, then it is likely to be the radiator (notwithstanding that it might be newish) silted up or the water pump. Take the radiator to a radiatior specialist and check that it is the right sort of core for the car and that the flow rate is right - pressure testing just tells you that it isn't leaking, their flow test will tell you how efficient it is. At the same time (as you will have drained the coolant anyway) remove the water pump and check that the impeller is a) still there and b) that it does not turn independently of the shaft.
MG Mark
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