20 replies to this topic

[1995spi]

my engine 1275 mg metro engine is fine in motion if anything it reads a little cold but in traffic the temp gauge shows its too hot spark plugs are white indicating its getting hot. a new thermostat new water pump and a new better rad have done little to help a auxiliary fan on the radiator has helped but still getting above N on a hot day in traffic is it time to do a compression test cpuld it be the head? no sign of head gasket failure 

[stuart bowes]

incorrect timing can cause overheating as well, might want to check on that

 

just something I've read, others will have to fill you in on the specifics

Edited by stuart bowes, 12 May 2025 - 11:10 AM.

[DeadSquare]

Ah, the sunny South Coast.

 

If it doesn't actually boil, don't get desperate.  Try a different Temp Gauge, before moving to Inverness

[1995spi]

Ah, the sunny South Coast.

 

If it doesn't actually boil, don't get desperate.  Try a different Temp Gauge, before moving to Inverness

even if the plugs are white when i look at them 

[DeadSquare]

 

Ah, the sunny South Coast.

 

If it doesn't actually boil, don't get desperate.  Try a different Temp Gauge, before moving to Inverness

even if the plugs are white when i look at them 

 

What colour is the exhaust tail pipe ?

 

Lean engines run hot, up to a point, so it might be worth turning the mixture, richer, a 1/4 turn for a start.

 

There used to be a special Spark Plug with a quartz dome, called a "Colour-tune", that in dark conditions, revealed the richness of the exploding mixture.

Edited by DeadSquare, 12 May 2025 - 01:24 PM.

[mab01uk]

Also check you have the correct pressure cap on rad. and also check it matches the rad neck depth. (88 degree thermostats and 15LB rad caps on A plus units).

Adding an expansion tank to the system can also help if not already fitted.

Edited by mab01uk, 12 May 2025 - 01:24 PM.

[Spider]

If it;s not going higher than 3/4 of the gauge, leave it, you'll tie your self in knots for no reason.

[Cooperman]

It might be slightly too far retarded or a bit too weak on the mixture, so check the timing and mixture.

Of course, it could simply be the gauge reading incorrectly - a common problem. Fitting a capillary-type gauge kit would answer that and I have fitted the kit from Mini Spares on both my cars. The gauge on my 'S' would go into the red very easily , but when I fitted the capillary gauge it rarely went above 95 C, even in traffic, and then went down a bit when I switched the aux fan on. It goes to just over 100 C on very hot days, and that's OK.

[Steam]

The mg metro engines can need more radiator / cooling capacity than a standard mini one.

[croc7]

my engine 1275 mg metro engine is fine in motion if anything it reads a little cold but in traffic the temp gauge shows its too hot spark plugs are white indicating its getting hot. a new thermostat new water pump and a new better rad have done little to help a auxiliary fan on the radiator has helped but still getting above N on a hot day in traffic is it time to do a compression test cpuld it be the head? no sign of head gasket failure 

If the indicating system is accurate and the rad is clear, could be that the water passages in the engine are not flowing coolant freely.  The best product that I found to clean the complete cooling system is made by CRC called Thermocure, I found it on Amazon (where else?).  Thermocure is a rust remover, not just a radiator "flush", plus you can drive the car while it does it's magic.  Its a bit more money than others, but worth it.  Try it, you can thank me later.....

[Ethel]

Aye, if it's leaded petrol spec engine the compression was pretty high even for 4 star.

 

As Spider says, it's easy to get spooked by what's little better than a wet finger in the wind as an indicator of engine health. There'll be some cause & effect guess work to whether it's lacking cooling or cooking itself through fuelling & timing issues. You might get a very rough clue by comparing different scenarios. Will it get hotter quicker if it's never got up to a decent speed or does it stay hot if it's had a run then gets caught in traffic, no matter how long for?

 

If it's a tuning issue you could investigate stuff that has more effect at part throttle.  Is that vac advance doing what it should? Are there any air leaks down  stream of the carb jet, throttle spindle, breather hoses, manifold gasket...?

[1995spi]

Aye, if it's leaded petrol spec engine the compression was pretty high even for 4 star.

 

As Spider says, it's easy to get spooked by what's little better than a wet finger in the wind as an indicator of engine health. There'll be some cause & effect guess work to whether it's lacking cooling or cooking itself through fuelling & timing issues. You might get a very rough clue by comparing different scenarios. Will it get hotter quicker if it's never got up to a decent speed or does it stay hot if it's had a run then gets caught in traffic, no matter how long for?

 

If it's a tuning issue you could investigate stuff that has more effect at part throttle.  Is that vac advance doing what it should? Are there any air leaks down  stream of the carb jet, throttle spindle, breather hoses, manifold gasket...?

if its got hot and then in free flowing traffic she cools down quickly 

[Ethel]

If you're not using much more throttle that hints at cooling, but it is just a hint as there are so many variables.

 

You'd expect the temperature gauge to normally settle around where the thermostat opens, to help reading it more meaningfully.

[Spider]

if its got hot and then in free flowing traffic she cools down quickly

 

So you have plenty of cooling capacity, it's just warming up from low pump and fan speed.

[m1n1]

I had a large water pump pulley on mine and it did get warm in rush hour traffic.  Switched to a slightly smaller pulley from a metro and its much better now.    Worth a go if you not using your metro one already.