Engine overheating?

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trmorrisminor
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Engine overheating?

Post by trmorrisminor »

Morning all, am in the process of restoring a austin minor van, been an ongoing project for past 7 years, finally got to drive the van up and down a housing estate road near my dads which is where the van is stored (its all taxed and insured). Engine seem to be very hot very quickly yesterday, with the temp gauge going upto near 90oc.Appreciate weather yesterday was very warm which would make things worse, but to rule out any potential overheating issues at this early stage, what options have I got? Rubber hoses, waterpump and thermostat are all new, radiator has been washed out and i think its good internally? I have read on a post some time ago about washing the system out with kettle descaler to make sure none of the engine bores are blocked? Is this the best thing or radiator flush? And then flushing it out with a hose both ways.Do you have to remove the thermostat after? Also i seem to have seen a post some time ago about doing a compression test? Any help would be greatly appreciated.
kevin s
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Re: Engine overheating?

Post by kevin s »

It should run in the mid 80's with a 82 thermostat, if you are only doing low speeds in 30 degree ambients with the std engine driven fan,90 doesen't sound unreasonable, did it stabalise there or was it still climbing?

You really need to take it for a bit longer drive at higher speeds to see what happens, they usually run hottest at slow speed / stationary but the temperature drops back once you are moving.

Compression test is looking for leaking head gasket or cracked head /block, if you have this it will run rough and be difficult to start, you will also get a constant stream of gas escaping out of the radiator overflow or in the case of cracks a mysterious loss of coolant.
philthehill
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Re: Engine overheating?

Post by philthehill »

The normal working temperature should be around 85 degrees centigrade so I would not get too concerned.
You could change the thermostat to to a summer setting one which would lower the overall engine temp.
https://www.moss-europe.co.uk/thermosta ... soc=136592
Last edited by philthehill on Tue Jul 12, 2022 10:24 am, edited 1 time in total.

nutsandbolts
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Re: Engine overheating?

Post by nutsandbolts »

Hi 90 degrees is about normal for standard running, if it is not losing water I would give it a longer run (take some water with you) if it boils up make sure you let it cool before topping up.

Hope this helps

Larry
the most unreliable part of a car is the nut holding the steering wheel!
trmorrisminor
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Re: Engine overheating?

Post by trmorrisminor »

Many thanks for all your inputs, much appreciated, the temp went up to early 90’s but i needed to do a few jobs for my dad so thats when i turned it off. Ok thankyou sounds like i need to take it for a longer run and see what happens. Will take a bottle of water with me, thankyou. Out of interest if I want to descale the engine and rad just to make sure so atleast I have a starting point with it ( not sure van was particularly well maintained when in use prior to me buying it eg no coolant etc so just want to get it to a standard where i know its in good condition) - what descaler is the best to use? - a rad cleaner or kettle descaler or something else? And how would you recommend i use it? Thanks again
simmitc
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Re: Engine overheating?

Post by simmitc »

Also check that there are no brakes binding and that the fan belt is at the correct tension. If the ignition timing is too advanced or the mixture too weak, both, can cause overheating.

How accurate is your temperature gauge?

Bear in mind that the winter stat is 88 degrees anyway.

After a long period of inactivity, I would always thoroughly flush the entire cooling system, including the engine, the heater and the radiator. Disconnect the heater hoses from the engine to aid flushing.

If the radiator is boiling over under pressure, then the head gasket may be at fault, but as others have said, I would expect other symptoms too, although a compression test never did any harm. For an accurate result, this is done with a gauge fitted to the holes where the spark plugs go. A quick test is by using the starting handle to turn the engine and confirming that there is roughly equal resistance at equal distances around the turns (turn the handle a few times to get a feel for it). This id done with the ignition off, plugs fitted, gearbox in neutral, handbrake on.

Overall, as others have said, I would run it a bit longer and assess from there.
simmitc
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Re: Engine overheating?

Post by simmitc »

You posted your update whilst I was typing my note above, so to pick up on your latest, use a proper car radiator flush product and follow the instructions on the bottle.

When the system in cool, remove the radiator cap and bottom hose and connect a hosepipe to the bottom of the rad to back flush that. Run until the water comes out clear.

Remove the thermostat and the heater hoses. Basically flush in all directions from wherever water comes out when squirting into another place. You can cover one exit point to force water round and out through another. Flush the heater in both directions.
nutsandbolts
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Re: Engine overheating?

Post by nutsandbolts »

Also bear in mind that if you are just pottering around the side streets on an estate the airflow through your rad grill will be minimal, on a run the airflow will be greater and may reduce the water temp. remember all the old cars boiling up in the traffic jams on the way to the seaside back in the day. Modern cars have electric fans which spin fast at low engine revs, older generation car fans only spin in relation to engine speed, so tick-over and slow speeds = a slow fan not pulling much air through the radiator. give it a good run and see what happens.

Good luck and keep cool!
the most unreliable part of a car is the nut holding the steering wheel!
trmorrisminor
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Re: Engine overheating?

Post by trmorrisminor »

Many thanks to you all for your input, much appreciated. Will hopefully be back over at dads in next few weeks so will let you know how I get on. Much appreciated for all your individual comments/ help.
Richard
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