Technical Seicento overheating

[Mark Ewing]

I have just bought my son a 2001 Seicento Sporting 1.1 Michael Schumacher to learn to drive on. It's covered 41,000 miles and seems well mainatained with a very clean engine compartment. Unfortunately, during driving practise around an empty industrial estate at weekends, with lots of 1st gear work and stop/start motoring the engine overheat warning light comes on. The expansion tank is full - a little overfilled I would have said - and there appears no loss of fluid. I can hear the cooling fan coming on, although strangely not when the warning light is on, only before that point. I'm assuming that this is not normal so returning the car to the vendor is the only option. I have left the car idling for 30 minutes and it didn't overheat at all, and the fan came on and off predictably. It just doesn't seem to like what would be the equivalent of a bad traffic jam.
Does anyone with experience of this model have any ideas?

 

[ilsonemo]

it could be air locks in the cooling system or it could be head gasket or thermostat, these are common faults for overheating

 

[Mark Ewing]

Thanks for that. I thought it was an air lock in the pipes too. I inspected them and squeezed them to check they were full of coolant and following that we had a practise outing without any overheating. As is often the case though, problems return just when you thought you'd got the better of them, and next time out it overheated again. This made me think that perhaps it was a head gasket or thermostat. The problem only seems to occur at rush-hour traffic jam type speeds. A damned nuisance as otherwise it appears to be a great little car.

 

[fingers99]

Very worthwhile bleeding it: the bleed screws are on a pipe which emerges near the windscreen reservoir (inner wing) in front of the expansion tank and at the back of the engine bay where the pipes go through the "carpet" to the heater.

For the thermostat, check that the top radiator hose gets thoroughly hot.

 

[Mark Ewing]

Thanks for that tip Fingers99. I will look into that today. I've noticed that the coolant looks pretty rank, but as we've not had the car for long I've nothing to compare it with.

 

[ilsonemo]

if the coolant looks rank then its probly oil in it, check your oil filler cap and see if theres any white gung in the cap, if so its sounding like head gasket

 

[fingers99]

if the coolant looks rank then its probly oil in it, check your oil filler cap and see if theres any white gung in the cap, if so its sounding like head gasket

Yeah, although rank as in loads of rust usually just means that no-ilrly one bothered to change the anti-freeze. A couple of flushes with plain old water will normally clean everything up, or your local factor will sell you a flushing agent (make sure it's safe for aluminium engines) for around a fiver.

As it turns into a fairly expensive job (head bolts, skimming, gasket set) and there are lots of other bits/parts which might as well get done at the same time (re-cut valves, adjust valve clearances, new valve oil seals, cam belt, tensioner, even water pump) makes sense to get the compressions tested before pulling the head.

 

[Mark Ewing]

Thanks ilsonemo. I've looked under the rubber bung on the left of the air filter housing on top of the engine, which is presumably what passes for the oil filler cap on this model. You are right in that I too was expecting to see the tell-tale white gunk inside it but there is no sign of that at all, so I am leaning towards the thermostat or fan temperature sensor explanation. Although I'm open to further experienced comment.

 

[fingers99]

Oil in the coolant, or mayo on the dipstick is a better indication. Most head gasket issues will also show up some strange starting or other slight misfires.

 

[marino]

I also have noticed that my shuie runs up to temp very quickly,I do not have any overheating probs but it does not take much for the fan to kick in , it seems as though the cooling arangement is not really sufficiant with such a small radiator also it's ever so cramped under a very small engine bay, the good thing is the heater works very quickly in the winter, i think all the stop/ start would easily make it get hot quickly, just try what advice you have been given ,fresh coolant flush and bleed the system and a new thermostat, best of luck.. ps i have slight gunge on the inside of the oilcap but coolant is clean this may be due to short journeys.