Hi,

Maybe somebody could help me, My daughter has a black 03 plate seicento sporting. As it went in for an MOT the car overheated and the mechanic couldnt continue with the test. It popped loads of boiling water out of the coolant bottle.

I went to the local motor factors and bought a new thermostat and a new rad fan switch (which doesnt fit)

I know that a head gasket failure is due to a cause of something. I have fitted the new thermostat and the water still boils up.

Q1, After how long of the engine running should the rad fan kick in?
Q2, where is the water pump and how could i tell if it is faulty?

ive used the search facility but cant find the exact answers im looking for

Cheers
Matt.

Had anything been done to the engine just before the MoT?

Did you get water out of both coolant bleed points, when you refilled it?

If you connect 12v to the fan 12v connector (not the earth) does the fan run?

When you run the engine does the heater hose warm up quickly, and then the top hose to radiator warm up?

Dont run the engine until after you test the fan runs, only run the engine with the heater set to on and the heater blower at max boost.

Did you get the fan switch from a Fiat dealer after quoting the VIN number?

Noel
P.S. the water pump is behind the cam belt, under your nose when you look at the alternator, standing in front of the car, if the hoses heat up quickly it is probably ok, the fan is the likely prolbem it runs all the time - almost. It should run all the time almost

on the back of the fan there is a connector, i bought a new rad fan switch but there isnt a removable switch, i would imagine that the rad fan switch would be where there is water so it could detect the heat.

Maybe im looking in the wrong place.

The bottom rad hose gets hot very quick, the top one does get hot but takes a little while longer.

Once i know the right connector to test i will try to see if the fan powers up.

Cheers

on the MPI, the fan is controlled by the ECU via a relay. there is no fan switch as such.

the waterpump is driven by the cambelt, it is a small tooth pulley just below the cam pulley on the left hand side of the engine.

ok

ive just put a live and earth onto the connector on the fan, there is no switch there.

The fan powered up fine.

Whats the next call for me?

Was the car ok in traffic jams before the MoT, that is does the car frequently get stuck in traffic jams?

Did you bleed the coolant through both bleed points until you got water?

If the fan did not run, before the car boiled the second time, and you bleed it properly, then the fuse for the fan and the earth connection for the fan are then next suspect items, - that you can check easily.

Did you quote the VIN number?

The pump pumps water into the lower hose, so it is pumping if the lower hose gets hot first, you have to remove the front drivers wheel first, if you need to access it. Then the inner wheel arch shield, then the cam belt cover. The pumps seem pretty good, the fan earths terrible

the car hasnt been used in about 6 months or so, its only been running again 2-3 days.


Is there a temperature sensor anywhere? no light is coming on the dash to indicate theres a problem, this leads me to believe there could be a sensor issue?

have you back flushed the coolant system? Could boil over due to a small blockage etc. Also are you replacing the lost fluid with "coolant" rather than just water?
Josh

ive fitted a new headgasket and had the head skimmed but i still have a problem with the water getting exceptionally hot.

I have also fitted a new thermostat.

The engine starts and runs fine which is great but the coolant is still getting abnormally hot, I'm having to stop the engine before it destroys the new gasket.

I have found 2 bleed screws for the coolant system if i take these out then the water flows right out of them. How can i tell if theres a blockage?

What could be the problem here?

Cheers

Are you taking the bleed screws out with the engine cold and not running?

Cheers

SPD

I took the bleed screws out when the engine was running and water just flows out.

What is the best way to bleed the system? Am i doing something wrong?

punto_power99 said:

I took the bleed screws out when the engine was running and water just flows out.

What is the best way to bleed the system? Am i doing something wrong?

Click to expand...

Hell yeah. You need to bleed the car with the engine cold and not running

Cheers

SPD

Do I take the bleed screws out completely? or just undo them slightly?

Take them right out until water flows, make sure water is still flowing as you put them back.

It may take a while for the water to get to both the bleed points.

Cheers

SPD

ok cool is this the right method for me then?

Drain water out again completely,
Connect all hoses etc,
Remove bleed screws completely,
fill water bottle,
wait for water to pull come out of bleed points,
refit bleed screws.

Is there anything i need to do to pump the water through the system like pinch the hoses or do i just leave it and wait?

Is there any more bleed screws? I have found 2, one of which on the bulkhead and the other next to the headlight, drivers side

cheers

matt

Sounds about right, and you've found the two bleed screws. You can pinch the bottom hose to help it along, but gravity does the best job.

Cheers

SPD

Ok cool,

I take it then when the water comes out then thats it, is there a risk of air getting back into the system if I screw the bleed screws back in whilst water is runnin?

will this method remove all air from the system? because there doesnt seem to be any pressure building up in the water bottle

punto_power99 said:

Ok cool,

I take it then when the water comes out then thats it, is there a risk of air getting back into the system if I screw the bleed screws back in whilst water is runnin?

Click to expand...

If you have water in the header tank and it is flowing out of the bleeds then only a little air will get back into the top of bleed loops - If you are clumsy I'd not worry

punto_power99 said:

will this method remove all air from the system? because there doesnt seem to be any pressure building up in the water bottle

Click to expand...

There should be pressure build up unless you have a leak or the cap is faulty. When you start up from cold (with the bleed screws done up tight) the heater matrix hoses should heat up immediately, the radiator top/bottom hoses heat up next after an interval when the thermostat opens, then the hoses should harden up, and dry off as they get really hot, the header tank cap needs to be screwed on tight, before you start the engine. There should not be a smell of anti freeze. The heater should be turned to hot, and the heater boost fan on.
Then after an interval the fan should run and stop and run and stop.
You need to be brave for this test it is less brave to run round and round the block with a tail gate full of water containers...if it boils while you are breezing along there is something wrong with the cooling system -independent of the cooling fan. the only caveat is my fan will run as I park it outside front door, after any long run, in any traffic/stationary conditions e.g. red traffic light, the fan can run...

In a garage they would have a scrap header cap with a tyre valve and would hand pump the system to 14 lbs or less to see if they could detect a leak cold, e.g. if the pressure drops too quickly.

Why did you replace the head gasket?

Noel

The engine has stopped running all together now.

I bled the water as i said i would, however water would only come out of the back bleed screw if you blew through the header tank?

The first bleed screw behind the light worked an absolute treat water flowed out nicely.

I started the engine and it ran sweet for about 2-3 mins water was fine then the engine cut dead and wont restart at all.

Any ideas?

The engine turns over fine but doesnt even sound like it want to start

what could cause the engine to die all of a sudden and refuse starting?