General Seicento loseing coolant

[dx90]

On my son's Seicento sporting 1.1 mpi 2002 it will lose at least 40mm of coolant every 6 months or less. It has been like this for the last couple of years. Is this normal or is there a small leak somewhere and where are the usual places to look?

Thanks

 

[Michael Dranfield]

Are you sure it's loosing coolant ? It could be leaking in to the combustion chamber through a faulty head gasket and been burnt with the petrol air mixture,if this is the case have a look at the exhaust with the engine at full temperature something that appears to be white smoke may actually be steam indicating head gasket failure.

 

[dx90]

Are you sure it's loosing coolant ? It could be leaking in to the combustion chamber through a faulty head gasket and been burnt with the petrol air mixture,if this is the case have a look at the exhaust with the engine at full temperature something that appears to be white smoke may actually be steam indicating head gasket failure.

Thanks for the reply Michael, My sons off out today so the engine will be fully warmed up to temperature when he gets back later and Ill take to opportunity to check.

Andy

 

[Jamieboy]

Also worth putting something under the car while parked to detect a pipework/radiator/water-pump out-leakage. What does the oil-filler cap and coolant look like? If they've changed appearance, it may be indicative of a water to oil-way leak or combustion chamber to water-jacket leak.

 

[rallycinq]

Are you bleeding the car fully when you top it up?

D

 

[irishcento]

that is a very slight leak,hard to find if its that slight.

6mth is a long time,and id say your son is doing a 1k / 2k miles in that time.

check all coolant hose clips are tight,

any damp carpet inside,heater matrix.

i wouldnt say its head gasket as if this has been going on for a few years you say,a bad gasket wouldnt last that long.

keep us posted

 

[Ralf S.]

Check the tightness of the bottom radiator hose. It vibrates a lot since it's attached to the unsupported end of the radiator. If it's wet, it's leaking. Don't over-tighten it since the radiator hose stub is plastic.

Check inside the o/s wheel arch liner. While that's off also look down the side of the engine which will be exposed now. If it's wet, then that's the water pump. Change it next time you change the cam-belt.

Thermostat is under the coil pack. Have a look down there for any pink/green crystals.

Also check the top hose on the header tank. The banded clip can work loose with time. If you can rotate the hose easily on the header tank stub then a new clip will sort it.

Finally have a look at the coolant hoses where they enter the car (at the bulkhead). Any pink/green crystals round there means the heater hose joint or bleed screw is leaking. Bleed screw needs to be unscrewed carefully or the head will detach from the thread. The hose joint would need a bit of silicon sealant on the joint (you need to split the joint, not just stuff sealant into it) and then a new clip (Fiat ones are single use and can't be tightened).


Ralf S.

 

[dx90]

Are you bleeding the car fully when you top it up?

D

Yes I bleed it last time I refilled and it still dropped so no air in the system.

 

[dx90]

that is a very slight leak,hard to find if its that slight.

6mth is a long time,and id say your son is doing a 1k / 2k miles in that time.

check all coolant hose clips are tight,

any damp carpet inside,heater matrix.

i wouldnt say its head gasket as if this has been going on for a few years you say,a bad gasket wouldnt last that long.

keep us posted

Correct on the mileage. Can't see any see any signs of leaking around the pipes but I will go around and make sure they are all tight. I've checked the carpet and it is all dry.

 

[dx90]

Check the tightness of the bottom radiator hose. It vibrates a lot since it's attached to the unsupported end of the radiator. If it's wet, it's leaking. Don't over-tighten it since the radiator hose stub is plastic.

Check inside the o/s wheel arch liner. While that's off also look down the side of the engine which will be exposed now. If it's wet, then that's the water pump. Change it next time you change the cam-belt.

Thermostat is under the coil pack. Have a look down there for any pink/green crystals.

Also check the top hose on the header tank. The banded clip can work loose with time. If you can rotate the hose easily on the header tank stub then a new clip will sort it.

Finally have a look at the coolant hoses where they enter the car (at the bulkhead). Any pink/green crystals round there means the heater hose joint or bleed screw is leaking. Bleed screw needs to be unscrewed carefully or the head will detach from the thread. The hose joint would need a bit of silicon sealant on the joint (you need to split the joint, not just stuff sealant into it) and then a new clip (Fiat ones are single use and can't be tightened).


Ralf S.

I will go through the list in the next couple of days providing I get some spare time if not the weekend.. I just bought some UV coolant dye to put into the system that might help track it down.

I will let you all know what I find.

Thanks all.

 

[Sporting Owner]

Hi I've had a couple of Seicentos that did this and on both occasions jubilee clip going into radiator needed tightening. When it happened last time someone advised me it could engine plug corrosion, so I put in some rad weld too, but didnt need to as it turned out to be the clip

 

[dac69er]

I had a slow water loss issue for years that slowly got worse.
It ended up being the heater matrix leaking so I could never find an actual leak.
Heater matrix is cheap and pretty easy to change if it is that.

 

[dx90]

I had a slow water loss issue for years that slowly got worse.
It ended up being the heater matrix leaking so I could never find an actual leak.
Heater matrix is cheap and pretty easy to change if it is that.

Still haven't found the leak. So it could very well be the matrix like you said. Where is the heater matrix mounted on the Seicento?


Is there a guide anywhere?

 

[David C]

Where is the heater matrix mounted on the Seicento?

Under the bonnet behind the trim panel at the back of the engine bay.

 

[dac69er]

and removing it is simply a case of draining the coolant from the system, undoing the 2 hoses and the 3 screws (i think) then you pull it out and slide the new one in.


put everything back together and its sorted. mine wasnt leaking much, but it was just a bit damp and corroded towards the bottom and was discoloured with the coolant.

 

[David C]

and removing it is simply a case of draining the coolant from the system, undoing the 2 hoses and the 3 screws (i think) then you pull it out and slide the new one in.


put everything back together and its sorted. mine wasnt leaking much, but it was just a bit damp and corroded towards the bottom and was discoloured with the coolant.

Yes should be straight forward and self-explanatory.
The Sei will have the control valve on the end that the Cinq doesn't have, but once the trim panel is removed it will all be there to see.

 

[dx90]

I have put some uv die in the system, so I will have a look and see if I can see it.



Thanks

 

[David C]

I have put some uv die in the system, so I will have a look and see if I can see it.

You’ll probably see the colour from the coolant anyway.