Astra H 1.6 overheat

[alessioblaupunkt]

Hello,
come in an Astra H 1.6 petrol, have changed thermostat housing, engine radiator, coolant,
if you start the engine and let it at idle the engine reaches 99C deg
but radiator is at room temperature.

You accelerate a little and the radiator start to become hot.
The problem is the radiator has these pipes:

1 I------------
2 -------------
3 ------------O
4 ------------RT
5 -------------
where:

I is water intake
O is water output
RT is radiator Temp Sensor
--- is the core of the radiator

part 1 from 3 is HOT
part 4 to 5 is COLD

the radiator Temp Sensor doesn't get hot even with engine at 105C deg
and radiator fan DOES NOT COME IN.

I stoped engine at 113C deg.

At what temperature does an 1.6 petrol must start the fan with AC off?

There is water circulation in every pipes.

I read water temperature in the hidden menu of display, it's the value that ECU read from
the thermostat temperature sensor.

[Stelaras26]

its strange that fan does not kick in ...did you check if it works/starts by enabling it through diagnostic??
2 temps sensors or one??

[Meat-Head]

On topic:-

1) drain using compressed air entire system

2) fill a bucket to correct amount, adding 1 litre

3) buy one of these https://www.ebay.co.uk/itm/Universal...4AAOSw7E1dMw8w

4) take the return pipe off coolant return, hold vertical, rev engine
If squirts sound like water pump or air lock

5) VAUGE MODE:-

Take sensor out of water pump, and use that as filling point

6) what happens if you remove thermostat temporary, boil in water
Is thermostat correct way round?

7) is it an electric thermostat, is any engine light on?

[synkrotronic]

Water pump,maybe?

[huwalsh]

Yea - had Astra doing same. Was impellar of water pump loose on shaft. Sometimes turning sometimes not.
Has this engine got electronic thermostat ?

[alessioblaupunkt]

@ sterar
Fan works via diagnostic¸
Fan works if I put a low resistance in place of the radiator sensor.

Engine has two temp sensors + the radiator temp sensor.

@MH
1) need time and patient
2) k
3) it's here
4) k
5) has no sensor in water pump
6) thermostat is correct, if remove and dismantled the moving part
the water temp stay normal.
7) mechanic thermostat, engine light is off, was on with previous thermostat

@golf synchro
I want to replace it but the mechanic say NOOOOOOOOOOOO!!!

@huwash
Impellar, nice.
Has mechanic thermostat. Is it the same of yours? Please answer.

[Meat-Head]

So, if you remove return pipe to tank, hold vertically and rev engine does it squirt upwards.

cant remember what car, but had one where the housing crumbled and got stuck in heater matrux

[Meat-Head]

Hate editing posts

does it pssssgsss when cap removed hot? Holding pressure?

but bicycle inner tube instead of coolant cap?

[alessioblaupunkt]

In the week an Opel Corsa entered for MOT so the car is parked an no one has touched the car.
I turn the key ehi it's petrol, has hidden menu as the astra h, lemme see at what temperature the fan start
99 none
105 none
108 ON very quite and it stay for two minutes,
let's accelerate a bit and the water temp goes down fast 1 degree every 3 seconds.

I'm still waiting the OEM sensor for the Astra.

[alessioblaupunkt]

This astra turn the fan on at 113C and off at 108C
Got new sensor in the radiator.
Removing the cap slowly there are bubbles but water does not overflow at idle.
Removing the right return line there is flow at idle, have to test in vertical.
Removing the left return line there is a small flow at idle, have to test in vertical.

Block say it turned at 93C degrees

[Meat-Head]

Removing the cap makes it boil. Does it ssssshhhbhbhssseshhhhh when removing cap?

[huwalsh]

Electronic thermostat if I rember correctly

[alessioblaupunkt]

Fiigured out.
Thermal thermostat, open over 100 degrees and it is correct for this model, so the fan must start after the thermostat opening point.

Car is ok, problem is owner, he think to have a '90 car that turn the fan on at 95 but it's a 2004 astra,
common work it.

Called two local Opil diler, one don't know, the other confirm yeah works a bit high this model.

No shower when opening cap slowly.
So problem is customer.

Problem? Customer.
Customer is the problem.
He reads forum.
He reads how to enter the hidden menu in his astra.
He reads an high temp.
He found no data on the forum.
He think his car is broken and the mechanic has no knowledge.
But mechanic found the correct data and after testing almost everything in his car and found nothing wrong that's the point where you
call ambulance for the customer.
Got paper in the hand with data and his engine code.
Customer left speachless after showing that all is correct and within specification.
Another (happy?) customer.
SOLVED

[mon666]

yes, you are right