Overheating

[jacester]

My Air Creation 582 is overheating. Radiator is fitted under the belly. Have replaced the thermostat, cleaned the radiator and checked the main jets. Temperature with two up will be between 85 and 100.
Any suggestions please

[Bacardi]

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[Bacardi]

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[IFLYHI]

What is your water anti-freez ratio

[V]

Hi Bac,

If the radiator is ok, then surely removing the thermostat should have a marked effect? There was no change when this was tried.

Not necessarily. I'm not sure about the 582, but on a number of car engines the complete removal of the thermostat does not cure the overheating, in fact it can make it worse. Typically there are two water circuts:

1. 'Long circuit': coolant flows through the engine and the radiator.
2. 'Short circuit': coolant flows through the engines, goes through a bypass and flows back into the engine skipping the radiator.

When the coolant's temperature is under the opening temperature of the thermostat, the termostat 'short-circuits' the radiator to make the coolant warm up quicker. Once the thermostat fully open the coolant goes through the radiator and the required heat exchange takes place.

Now taking out the thermostat can cause coolant to partially flow through the radiator and partially through the by-pass. This makes the whole system very inefficient and the overheating problem will persist. But again, this depends on the cooling system's design. There are designs where the failure of thermostat will cause water to be forced through the radiator preventing an overheat. (Most modern cars have this arrangement.)

In my experiences (with cars that is) the best one can/should do as last resort is to slighly increase the diameter of the flow-through hole on the thermostat.

If radiator has been pressure tested, flushed, ensured that there is no blockage, radiator cap valve is in good condition and of correct pressure rating, then I would start looking at the engine: head gasket, warped head, cracks in the cylinder walls, sticky main bearings, etc. But I'm sure the 582 experts will be able to give you much better pointers.

[John Young]

My Air Creation 582 is overheating. Temperature with two up will be between 85 and 100.

Hi Jacester,

Is it in fact overheating?

There are 5 principal considerations [amongst others] in a cooling system, namely;

1. Radiator – this you have had flushed and cleaned – so “assume” OK.

2. Thermostat – a new thermostat means nix! Press a feeler gauge into thermostat and place in a pot of water. Heat over stove and using a thermometer, measure the stages of the thermostat. Thermostat should start opening at 70º C [thermostat drops off feeler gauge] and be fully open by 85 – 95º C.

3. Anti-freeze [which is a misnomer]. Anti-freeze is in fact a coolant inhibitor – it prevents corrosion more than anything else. A 50/50 mix should see you through most ranges in a given year. Some people will suggest that a higher ratio will increase temperature – I am not so sure.

4. Sender unit – in most configurations, the lower the reading in ohms, the higher the gauge will read. In my unit, at ambient temperature I get 125 ohms and at normal operating temperature, some 70 ohms. Compare your readings to other similar trikes.

5. Temperature gauge – if this is a decent unit, like a VDO etc., then I suggest you go to points 2 & 4.

Regards
John ZU-CIB