Sera Problem!

[ta3ban]

i have sera 1991.. and iam facin a probelm with coolin system.. i drive for 15 minutes then the heat meter rises to the top.. then it goes back to normat temp.. that happens a couple of times then the heat meter stays on top like its gonna blow, and it becomes sooo hot ...the water level is normal, it doesnt leak.. i cleaned the radiator, i changed the pipes for it.. but still the same problem... any suggestion ?? :censor: :censor: plzz help

[aj3001]

Have you checked to see if its getting hot or if its just the gauge?

Sorry if its not helpful, I have never done any work on my car (I only got one 2 months ago) so I cant be any more helpful due to lack of experience

[toyotasera.co.uk]

Well it could be a thermostat problem or a head gasket problem.

[LORD_ED]

air lock?

[ta3ban]

maybe the thermostate or head gaskate!!.. cuz when i checked the radiator as soon as i turn on the car i can see the water runnin through normaly.. what about that "air lock" what do u mean with that? but how does the head gaskate effect??

[toyotasera.co.uk]

Right.

The job of the thermostat is to regulate the temperature of the engines coolant. When the engine is cold the thermostat is closed and the water circulates around just the engine, not the radiator. When the engine reaches a certain temperature, the thermostat opens and allows water to pass through the whole coolant circuit, including the radiator, where the heat from the engine is removed due to the air flowing through the radiator.

Sera thermostats normally fail in the open position which means they take engines for the water temperature to reach halfway, and the temperature often changes with road speed.

Thermostats can often fail shut and this causes the engine to overheat rapidly.

Radiators are a heat exchanger, in this case, the heat from the water flowing through it, is passed onto the air flowing over its surface. They have a large surface area to maximise the amount of cooling that can take place. If the radiator is blocked internally, either due to internal corrossion or build up of dirt / silt, then it will overheat because water can't flow properly. If the radiator is blocked externally, it will overheat because air is restricted.

Head gaskets are often a symptom of another problem, but a blowing head gasket can pressurise the cooling system with hot exhaust gases. This increase in pressure and heat can display erratic temperature settings, but if you're not losing water I would possibly discount this.

As its hard to diagnose a problem remotely, I would take the car to a mechanic to check.

[ta3ban]

thx for all this explanations.. i let the mechanic to clean the radiator twice.. when i first bought the car, the radiator was closed internally and it was all coloured in orange.. but its now normal.. so i dnt thik its about the radiator (right??).. but i notice that the engine overheat rapidly so it may be about the thermostat (right??)..but what u said about the thermostat "When the engine is cold the thermostat is closed and the water circulates around just the engine, not the radiator. When the engine reaches a certain temperature, the thermostat opens and allows water to pass through the whole coolant circuit, including the radiator".. what do u mean exactly with that? cuz as soon as i turn on the car in the mornin i can see that the water is flowin through the radiotor (the top, when i open it).. is it from the water pump? or thermostat!??

thx allot

[toyotasera.co.uk]

The water pump is turning always - its the heart of the cooling system. If this fails, you're in big trouble.

With the engine cold there should be little flow in the radiator. Change the thermostat first - its cheap (€ 15).

[ta3ban]

but i dnt think i can find thermostat for sera in cyprus.. or its common for toyota cars.. or any other brand?

[toyotasera.co.uk]

same as Paseo and Starlets with E-series engines (4E-FE / 5E-FE / 5E-FHE / 4E-FTE)

[ta3ban]

thx..i will change thermostat with the one for starlet.. and i will post what will happen with me in few days..

[ta3ban]

today i noticed somethin in the car.. i stopped on the red light the gauge started to go up to high.. but when i moved the car on the green light the gauge started to go to the middle as normal... as soon as i push the gas the gauge stats to go down... !!!! whats the problem??

[toyotasera.co.uk]

have you changed the thermostat yet?

[ta3ban]

not yet.. iam goin to the mechanic tom mornin..but r u sure its about the thermostat??

[cynos_boy]

Have you checked whether the electric fan switch is working?

See if the fan is actually coming on when stopped/engine heating up...

[ta3ban]

i called the mechanic and he told me that he removed the thermostat like 2 months ago.. to keep the radiator coolin as he said... what shall i do?

[ta3ban]

i checked the fan today.. its workin normally!!!

[toyotasera.co.uk]

He should have replaced the thermostat, not removed it completely.

The thermostat is there to regulate the cars temperature - not too cold and not too hot. If it was faulty then removing it was sensible for a temporary measure but it should be replaced with a new one.

Your mechanic doesn't sound to be very good.

[ta3ban]

so u mean that if i put new thermostat it will fix the problem?? cuz i wanna be sure, everythin here is soo expinsive and i dnt wanna spend much money on the car!! and the mechanic told me that to change the head gasket i need aound 200 CY pounds (500 $)..

[toyotasera.co.uk]

The problem is that we don't know exactly what the problem is. We know what some of the symptoms are but the problem hasn't been diagnosed, and its hard to do that when I'm in one country and you are in another.

Fitting a new Thermostat is easy, you can do this yourself and it costs about € 15 for a new Thermostat from Toyota. I know a Sera owner in Cyprus who may be able to help with a trusted mechanic.

[ta3ban]

i will put new thermostat soon.. and i will try to search for good sera mechanic.. well, if u know 1 then tell me.. thx

[Jim in New Zealand]

i will put new thermostat soon.. and i will try to search for good sera mechanic.. well, if u know 1 then tell me.. thx

The problem is the missing thermostat. When hot it switches the flow FROM recycle TO through the radiator. Removing it was ignorant. :D

[Impressive G]

personall, if you didn't want to spend a lot money on parts for your car, then you shouldn't have got a Sera dude!!!!

[Jamesb4uk]

Way to bring back an old post & upset the Sera lot...

J

[striker1]

Ive dealt with these problems a few times and what i think is that the main problem is your therm. and your temp gauge is going out. but as i say in a lot of my posts, thats just a best guess with the info i have. good luck