Hi.
Hoping someone can give an idea what my issue is.
I have a gen 7 Celica and this morning I couldn't get any heat on my way to work.
Figured it could be an air lock, however when driving home this evening the temp gauge kept going to hottest then back down every few minutes.
When I got home I lifted the bonnet and there is coolant splashed all around near the coolant reservoir.
My initial feeling is that this isn't good.
Any ideas where to start?
Thanks
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Firstly don't drive the car until you get this fixed.looks like you have run out of coolant and water . There may be a radiator Cap in addition to the coolant expansion bottle,but you need to remove the plastic covers over the radiator area for access.the system will need bleeding and inspection for leaks
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Hi.
Thank you for posting.
I am not mechanically minded and the car is on the drive now.
When you say there may be a radiator cap in addition do you mean the cap could be leaking?
Do you happen to know the easiest method to test for leaks and to bleed?
Thanks
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If you are not too sure what is happening,then I think it would be a good idea to consult an expert.Take it to a local garage.(arrange a pick-up) A cooling system in trouble could wreck your engine.
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Have you got sufficient anti-freeze? If not then ice could form in the radiator due to the cold air passing through it. The will block the radiator leading to engine overheating. The coolant loss around the pressure cap will be due to the cap lifting letting off excess pressure as a result of the high temperature. Check the anti-freeze strength first and change the thermostat.
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Thanks for the replies.
Had a look this morning and the coolant level in the header tank is between min and max.
Also looked at the oil cap and and no white substance.
It was -4 when this occurred which is very cold for here.
Wonder if water to antifreeze level is low on the antifreeze ratio and there was a frozen blockage?
Either that or the thermostat?
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Thanks for the replies. Had a look this morning and the coolant level in the header tank is between min and max. Also looked at the oil cap and and no white substance. It was -4 when this occurred which is very cold for here. Wonder if water to antifreeze level is low on the antifreeze ratio and there was a frozen blockage? Either that or the thermostat?
Sounds like it, and in any case it's the first thing you should check. The outside air may be -4°, but factor in the wind chill as you drive and the air will be colder than that. In no time at all the radiator will be a solid block of ice.
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Wind chill only affects warm-blooded animals, including humans - it doesn't affect cold-blooded animals or inanimate objects.
Cold air flow won't cool a cold object below ambient temperature - not withstanding the temperature change associated with a pressure drop, ie carburettor icing.
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If the coolant has frozen,then it is possible that the water pump may have been damaged.
Also,is not windchill a "human "perception.A temp of -4 is -4 however fast you travel?
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Well whatever. The fact remains that the coolant will not be flowing through the radiator when the engine is cold and the thermostat is closed. Add to that the radiator galleries are very narrow, the stagnant coolant with low anti-freeze protection will freeze in the radiator as the cold air passes through it. By the time the overheating issue has been investigated the ice will have melted and any trace of evidence of the fault will be gone. Perhaps this is an advantage of having down roadside breakdowns for many years. You get to see faults first hand, whereas garages do not.
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So to test what's gone on tomorrow when it's warmer and anything frozen has thawed out, where to I start?
Burping the system?
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Get a simple anti-freeze tester, only £2 at H***ords or similar - it's just 3/4 balls of which a variable number float according to the anti-freeze concentration. They aren't super accurate but will tell you if you have almost plain water.
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Engine cooling systems are very simple. The problem is people make them out to be far more complicated than they really are. Air can't get into the system unless you have a leak, so there's no point blaming a mysterious air lock. It can't just happen. As I said earlier you should change your thermostat. You should do this anyway if the engine has overheated and the thermostat will have lost its wax. Then refill the cooling system having removed the temperature sensor or other component which is at the highest point on the cylinder head until coolant comes out from that point. Do not run the engine whilst filling up. When coolant comes out at the highest point the system will be bled. Refit the component and the pressure cap and start the engine and allow it to warm up.
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Modern cooling/heat systems have a number of valves/thermostats which are difficult to get all open at the same time. Air/gas can be introduced if a fault exists and coolant is expelled, with air being drawn back in as the system cools.
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Air does get drawn back in as the engine cools - via the pressure cap, otherwise the cooling system hoses would be vacuumed flat. It's impossible however for this air to get underneath the coolant, and therefore induced air locks cannot happen. The reason why cooling systems get air locked is because they have not been properly bled following repairs, or when the system has been drained. The water pump is a centrifugal pump which is used in high flow low pressure applications. The pump must be fully submerged as it will not purge air very well. Once the cooling system is bled there is no way in for air except through one of the two one-way valves in the pressure cap. One allows excess pressure to escape, the other allows air into the top of the system as the engine cools and the coolant contracts.
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Turbochargers are centrifugal pumps, just like water pumps - very effective a moving huge amounts of air.
Within the fault category, a minor head gasket leak can allow turbocharged air into the coolant, not neccessarily with any trace of exhaust gas, and this air can then push the coolant out of the expansion bottle - I've had this happen on two cars so I know it's possible.
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Very true A turbo charger is a centrifugal air pump, and so is a hairdryer. They move air very well, as long as that air has somewhere to go. If air is trapped at the bottom of an engine block the pump will just rotate in that air. If a head gasket had failed even only very slightly then the upward movement of the piston on the compression stroke will force air into the cooling system, but that would mean there's a fault. Air cannot get into a sealed system just because it feels like it.
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Hi All.
I had a go at bleeding the system yesterday and during the process the coolant in the header tak went from the max line to well below the minimum.
I started to get heat blowing so I took it out and the heat stopped and it went back to high on the temp gauge.
A neighbor thinks it's the thermostat stuck closed.
I have taken it to a local garage this morning and should know soon.
As a ballpark what should be the cost of a new thermostat and labour?
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So it's bad news.
Head gaskets gone.
Thanks for all the replies.
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