Hello everyone,

I know this topic has been exhausted but maybe the variables in my situation are different...so bear with me please.

Alright, so the day before yesterday I go to this specialist and we flush the cooling system, give it a good rinse and put it back together with the coolant hose adapter for my newly acquired temperature gauge.

Next we leave the motor running and wait for the fan to kick in but it doesn't. While checking the temperature sensor connection and probably giving it a nudge it starts working so I'm off... Fan comes on normaly for a day but yesterday it stopped working again.

If I short the connector to the radiator temperature sensor, the fan come's on, so I figure the sensor is acting up and replace it this morning. Again the fan doesn't come on .. I let it boil and bleed it .. fan comes on... which makes me assume the sensor wasn't to blame for in the first place...and there's trapped air inside the radiator giving the sensor bad readings.

I drive it around for a while ..fan doesn't come on again! :bang:

I also noticed yesterday that there was a little leak on the gauge coolant hose adapter so I changed the jubilee clips with better quality ones than the ones that came with the adapter. Today AGAIN I notice some bleeding under the adapter...

What do you make out of this ? Could it be air coming from the adapter leak causing the problem ? It's doing my nut in.... I don't know what else to do with the adapter... I also screwed the sensor in really tight with teflon tape.

Any ideas ?

p.s.
The gauge looks really good fitted under the radioCD ! I will post pictures in the guide which are missing, on how to get the wire from the engine bay inside.

Cheers

If the gauge adaptor is a wee bit small for the hose overtightening the worm clip will cause the hose to kink and leak.

Wrap some PTFE tape round the gauge adaptor to make it bigger, it then should seal better.

Cheers

D

Umm yeah, I see what you're saying...but I think I got the correct adaptor ...30mm and it also needed a little grease to get the hoses on.

OK, take it back out, clean all the grease from the hose and the adaptor and reassemble using washing up liquid as the lubricant.

You could also use any water based lubricant if you happen to have any around.

Cheers

D

yeah I was thinking about that might being a problem when the "specialist" put the grease on to fit it ... I'll go try it now thanks!

No dice... I removed the adaptor, washed it and refitted it but temp almost reached 100c and fan didn't come on again :bang:
I probably haven't bled the system correctly ... here's how I go about it, correct me if I got it wrong:

1) I have the coolant tank open, I turn the heater to HOT (heater fan off).
2) I fill the coolant tank a bit above MAX
3) Engine running, feeling the lower radiator hose hot so assuming thermostat is open.
4) Bleeding the top valve first (heater matrix) while squeezing hoses here 'n' there.
5) Bleeding the lower valve near the coolant tank while squeezing hoses.
6) Coolant started to get hot so I closed and tightened the coolant tank cap.

p.s


I posted some nice pictures on the gauge guide by the way if anyone's interested: https://www.fiatforum.com/cinquecento-seicento-guides/86286-temperature-gauge-fitment.html?p=2608258

The fan could be intermittent, e.g. does it spin freely?

Noel

it may take a few attempts to fully bleed it. i dont think you should have the tank cap open

@Pep0: Yes it spins freely if I short the switch with a bit of wire

@dronenrs: I will try to bleed it again tomorrow

anything else I could try lads ?

Bleed it cold, no engine running.

Overfill the coolant tank, open top bleed hole till fluid comes out.

Close top bleed hole, open bottom one, same.

Use bottom one to reduce level of coolant.

Operate engine till thermostat opens, switch off and allow to cool.

Rebleed as above.

Cheers

D

With a cool system and engine switched off no fluid comes out when I bleed the top hole..

Something else I noticed is when the engine is running and all water pipes are hot to the feel, if I bleed top/lower hole the first second of bleeding coolant always comes out cold...and after a short while really hot.

what do you reckon ?

v0rtex said:

With a cool system and engine switched off no fluid comes out when I bleed the top hole..

Something else I noticed is when the engine is running and all water pipes are hot to the feel, if I bleed top/lower hole the first second of bleeding coolant always comes out cold...and after a short while really hot.

what do you reckon ?

Click to expand...

thats normal

the top bleed pipe wont bleed when the car is cold as there is no pressure in the system and its above the resviour

the water in the small amount bleed pipes don,t circulate around the cooling system it just stays there as the pipe is so small


Ash

Please help me diagnose the problem...

- From what I've gathered from reading similar threads and your replies on this thread the cooling system appears to be working fine, all water pipes feel hot and the thermostat is opening since the top radiator hose is hot.
In addition the system was flushed and cleaned (that's when my problem started)

- The fan turns on if I short the switch that goes to the temp sensor mounted on the radiator and looks to be in good working condition.

- The radiator temp sensor switch was replaced yesterday with a new one from FIAT.

- I have checked the temp sensor connector and stuffed a few threads of wire inside each connector (just in case there was a bad connection with the radiator temp sensor)

- All fuses are good (also checked the big one behind the battery)

- I have bled the system over and over again

- If I let the car run and reach 100c, then short the fan switch and let it blow for a while the temp drops to 80c

To recap, the problem is that the radiator Fan doesn't kick in! Heeeeeeeeeeeelp!

p.s.
I had the horn removed for a while to be able to get my hands and replace the radiator temp sensor ...now i've mounted it back it doesn't work :bang:
I push the horn and can only hear a clicking/very very weak horn sound.
Could this be related in any way?

well the next thing i would try is gettin a voltmeter or multimeter and seeing if your getting a 12 volt supply to the fan. and check resistance too. it could be a wiring fault

I don't understand what you mean... The fan kicks in and works if I short the switch..which means it's getting the 12v.

It has to be a problem with the switch in the rad.

The problem started when you changed the coolant.

When the car is at its very hottest does the switch have a resistance of nearly zero?

Silly idea.

Put strong gloves on and remove the rad temp sensor when the engine is hot.

Do you get a lot of water coming out immediately?

If there is a blockage in that end of the rad that is stopping the hot water reaching the sender then the fan will never come on.

Possibly the change of coolant has moved something in the rad.

Cheers

D

Finally it is fixed! :slayer:

I removed the rad temp sensor while it was still warm/hot and it vomited everything out so no prob with the rad. I also replaced the rad temp sensor *again* with a generic type (92c) with different connectors.

And the problem was the original FIAT-type connector for the rad temp sensor...!

Big Thanks to everyone for their input and suggestions!