106 overheating - in winter!

[smele]

As it says, the little 106 seems to be overheating and its winter. Takes a long time for the heater inside to work and afer a while when you come to a stop the fan kicks in very quickly. Also the temperature light came on the other day within 2 mins of starting from cold. Stoped let it cool down, then it was fine.

Not sure what is wrong, it's full of water no leaks anywhere. It's almost like the pump is not working very well, but I thought they just worked, leaked or sheared off.

Any ideas? Thanks.

1995 1.1 230K miles

[GreenV8S]

My first guess would be the stat has failed partially open. One way to check that is to monitor the flow through the rad as it warms up from cold. The rad should stay stone cold until the engine comes up to the stat opening temperature. As it warms up further the fans should come on, cool the radiator down and then switch off again; they should keep doing this indefinitely. If yours behaves differently then that might give a clue where the problem is.

[smele]

Thats a good idea, but I forgot to mention that I replaced that a couple of months.

[GreenV8S]

smele said:

Thats a good idea, but I forgot to mention that I replaced that a couple of months.

I suggest you do the checks I suggested anyway since that will tell you one way or another. Just because it was replaced, doesn't mean it's working correctly.

[smele]

Will give it a good going over on Saturday. Seems likely, even though it is a newish thermostat.

[busta]

Did you bleed it after fitting the new 'stat? If not it'll probably have an air lock somewhere, usually o/s rear corner of the engine bay.

There is what looks like a valve cap on the coolant pipes there. Get the engine warm, unscrew it until you hear air hissing out then when coolant starts to dribble through tighten it up again. Remember to top up the coolant level when it cools down again too.

There is another bleed screw on the n/s top of the radiator.

You can make the whole job easier if you make a funnel out of an old 1 litre coke bottle; cut the bottom off, put a couple of turns of insulating tape around the threads on the top and it will fit nicely into the expansions chamber filler. Fill the bottle up with coolant to a level higher than the highest point of the engine, then undo the bleed screws until coolant runs through.

[smele]

busta said:

Did you bleed it after fitting the new 'stat? If not it'll probably have an air lock somewhere, usually o/s rear corner of the engine bay.

I think you are right with the air lock. Last time it was bleed and seemed to be ok. The touble is air is getting in and water is getting out with no noticable leak. Looks to me like the head gasket is probably going.

Oh well, I shall just have to keep bleeding it and keep some water in the car.

[busta]

I doubt it is head gasket if theres no mayo in the engine. Just keep doing short journeys, let it sit for a while so the air can wrk it's way to the bleed screws then bleed whilst it's still warm. I've had similar problems on both my 106s. It does always seem like they are using water until the system is fully bled, it's surprising how much air gets trapped in there!