I noticed a small puddle under my seicento 2001s 1.1L this morning. It's definitely coolant (I tasted it) and it drips from the seal of the sump on the left-hand side (or driver's side) of this (continental) car (see pic). Tightening the bolts of the sump don't anything, probably logically. There's no mayonaise in the oil reservoir nor thick white smoke when I start the car, making me think that the head casket is probably intact. Any suggestions where the coolant may leak from?

Likely leaking from the coolant pump

Aye, either the pump or possibly the solid pipe coming from it.

Hi Brickfoot, thanks for your swift response!
Being a newbie this may be a stupid reply, but isn't the water pump located on the righthand side (i.e. passenger's side of a continental car) of the motor block where all the belts etc are?

clave said:

Hi Brickfoot, thanks for your swift response!
Being a newbie this may be a stupid reply, but isn't the water pump located on the righthand side (i.e. passenger's side of a continental car) of the motor block where all the belts etc are?

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Yes, however, if it's coming from the other side, it'll be a knackered thermostat gasket

Thanks brickfoot, that put me on the right track: while inspecting the thermostat gasket (fine) I noticed some wetness around the head gasket, which turned out to be indeed coolant. The leak is not very bad, spilling ~30 drops per day.

Since there's no mixing with oil (as of yet I think) how severe is this (on a scale of 1: take no action to 10: don't drive with it)?

clave said:

Thanks brickfoot, that put me on the right track: while inspecting the thermostat gasket (fine) I noticed some wetness around the head gasket, which turned out to be indeed coolant. The leak is not very bad, spilling ~30 drops per day.

Since there's no mixing with oil (as of yet I think) how severe is this (on a scale of 1: take no action to 10: don't drive with it)?

Click to expand...

If it's coming from a gap between the block and head, it will certainly be head gasket.

I would get this looked at ASAP. On the scale, 7-8. If it fails completely, you will end up with an overheating engine, which can possibly lead to a warped head and complete head gasket failure.

If it does fail between the coolant and oil channels, then it will mix with the oil and result in knackered bearings if not caught. The coolant loss will also lead to overheating, and then refer to the point above.

Find a trustworthy garage and get them to do a compression check on the cylinders, if the end cylinder (by the leak) or two cylinders together are a lower compression, then the head gasket is failing. They may also be able to do a coolant pressurisation check to find any leaks.

If you change the head gasket before you have a full failure, and change the thermostat and waterpump and cambelt at the same time, then it should be an economic repair for a 15 year-old car. It could be the garage will recommend a simple cylinder head overhaul at the same time (light skim and new valve seats), this should not be very expensive if the head has overheated.

You will also need the valve clearances reset after this work (adjusted by swapping shims).

But if the head gasket is OK, try a new thermostat and new coolant.