barrymckenzie73
New member
- Joined
- Aug 16, 2006
- Messages
- 2
- Points
- 1
Hi,
I've been taking a look at my Sisters 900cc Seicento which has started boiling over out of the expansion tank cap.
This had happened once or twice before she got it to me. She had bought it a few months earlier and had no problems in those months.
Initial investigation: Car idling, hot water flows around heater ( smaller diameter ) hoses as expected, oberved by feeling the hoses. Eventually Thermostat opens and Top Rad hose gets hot. Radiator starts to get hot at the top. Before bottom rad hose gets hot ( 3 mins ) the car boils up.
I assumed the problem to be either
1) The water pump not pumping the water around quickly enough as it seems to take a long time for the hot water entering at the top of the rad to reach the bottom. I took the side cover off the water pump and confirmed the impellor was still on the pump shaft and that it was secure and turned when the engine did. I did think the impellor did look tiny though compared to other cars.
2) Blocked radiator. I found the radiator had a small leak, so assumed the problem was caused by that. Had the rad recored, bled the system and the problem still exists.
However, its fine if you have the heater on blowing hot.
PLease dont ask if I bled the system, yes I did, both bleed nipples open.
Having read the forums, the additional causes could be:
3) Expansion tank cap not holding pressure: I will buy a new cap tomorrow, however to me, the system appears to be pressurised as the hoses are very firm when hot compared to when cold.
4) Fan: Works when shorted and spins freely.
5) Fan Switch: Tested in a pan of water on heat, it opens / closes around 90 degrees.
4) Thermostat: I have felt the top rad hose go from cold to hot indicating that the thermostat has opened.
To me its as if the water pump is not circulating the water quickly enough, how can this be ?
Two more things :-
a) WHen filling the system with water, it appears that the water takes a long time to fill the systems. i.e you top it up, the level drops, you add some more, it drops again. Eventually the systems fills up. Its as if there is a blockage in the block... can this happen ?
b) There apears to be air bubbles in the coolant, I have felt them when squeezing the heater hoses -> Headgasket ? although no water in the oil and no oil in the water.
Is the water pump impellor meant to be so tiny ?
Could the thermostat be slow, I thought they failed simple open or closed ?
Can the block get clogged ?
Help....
I could only assume the failed internally ( Impeller spiining on shaft or fell off completely ) However
I've been taking a look at my Sisters 900cc Seicento which has started boiling over out of the expansion tank cap.
This had happened once or twice before she got it to me. She had bought it a few months earlier and had no problems in those months.
Initial investigation: Car idling, hot water flows around heater ( smaller diameter ) hoses as expected, oberved by feeling the hoses. Eventually Thermostat opens and Top Rad hose gets hot. Radiator starts to get hot at the top. Before bottom rad hose gets hot ( 3 mins ) the car boils up.
I assumed the problem to be either
1) The water pump not pumping the water around quickly enough as it seems to take a long time for the hot water entering at the top of the rad to reach the bottom. I took the side cover off the water pump and confirmed the impellor was still on the pump shaft and that it was secure and turned when the engine did. I did think the impellor did look tiny though compared to other cars.
2) Blocked radiator. I found the radiator had a small leak, so assumed the problem was caused by that. Had the rad recored, bled the system and the problem still exists.
However, its fine if you have the heater on blowing hot.
PLease dont ask if I bled the system, yes I did, both bleed nipples open.
Having read the forums, the additional causes could be:
3) Expansion tank cap not holding pressure: I will buy a new cap tomorrow, however to me, the system appears to be pressurised as the hoses are very firm when hot compared to when cold.
4) Fan: Works when shorted and spins freely.
5) Fan Switch: Tested in a pan of water on heat, it opens / closes around 90 degrees.
4) Thermostat: I have felt the top rad hose go from cold to hot indicating that the thermostat has opened.
To me its as if the water pump is not circulating the water quickly enough, how can this be ?
Two more things :-
a) WHen filling the system with water, it appears that the water takes a long time to fill the systems. i.e you top it up, the level drops, you add some more, it drops again. Eventually the systems fills up. Its as if there is a blockage in the block... can this happen ?
b) There apears to be air bubbles in the coolant, I have felt them when squeezing the heater hoses -> Headgasket ? although no water in the oil and no oil in the water.
Is the water pump impellor meant to be so tiny ?
Could the thermostat be slow, I thought they failed simple open or closed ?
Can the block get clogged ?
Help....
I could only assume the failed internally ( Impeller spiining on shaft or fell off completely ) However