coolant warning light

raven_inc · Post by **raven_inc** » Mon Oct 30, 2006 9:50 pm

Hi there all, great forum by the way as recently bought my first peugeot 406 and have learned loads about the car

However,

Have had the car (a 406 2.1 td glx) for about a month. During the first two weeks the coolant light came on intermitently
when driving, but the cars temp didnt rise at all. Stopped the car, let it get hotter, fans kicked in and down the temp needle went down.

Topped up the coolant (and only by a small amount as it was nearly full) and off i went again. Two weeks and 1000 miles later and on it goes again

Have done a check for the head gasket (i think) by running the engine with the coolant cap off to check for bubbles and apart from the obvious heating
up of the coolant - nothing.

Anyone think this could be electrical, or should i just see this as the head gasket starting to go, car has only got 71000 on clock and
I know the previous owner so its genuine miles. No oil leaks i can see and have full oil pressure.

Help!

mjb · Post by **mjb** » Tue Oct 31, 2006 8:21 am

Odd you don't mention the usual severe performance degradation associated with the light coming on as the car enters the dreaded limp home mode. Did this not happen? If not, then I'd pull the instrument panel out and have a check for anything shorting around the coolant light area

Post by **Welly** » Tue Oct 31, 2006 10:36 am

It sounds like you are topping it up, then a couple of weeks later topping it up again.

Is it the 'radiator looking' warning light? this is triggered by a low water level in the expansion bottle.

It may be that you have a tiny weep from the radiator (common) look at the bottom in the corners of the rad for greenish staining etc.

Also the water pump might be weeping, sometimes it's hard to see as the water collects on the undertray (if you still have one) and only runs off when you drive along.

I would look for signs of leaks myself and I doubt it's the head gasket, I don't think it's really a problem on your engine.

deathbydiesel · Post by **deathbydiesel** » Tue Oct 31, 2006 5:54 pm

When you topped up the coolant, did you use a header tank? Due to the expansion tank on a 406 being placed lower than than some of the hoses (why?) you have to use a header tank, make one by cutting either a old antifreeze/screenwash bottle (small 1.5l litre job) or a 3 litre squash botlle, place the neck of your "header tank" onto the expansion filler and remove the top bleed screw (top hose going over top of engine, looks like a tyre valve) fill system until water starts coming out bleed valve, put the cap back on the bleed valve, start engine and put heater on hot full belt, continue filling until no more water goes in, replace expansion cap and relax.HTH

chili · Post by **chili** » Tue Oct 31, 2006 6:49 pm

just sounds like an air block.....bleed it

raven_inc · Post by **raven_inc** » Fri Nov 03, 2006 7:24 pm

Many thanks for ther replies guys, the car has been pretty far from my mind as my wife gave birth to our first child on Wendesday

Will have a good look around for leaks and also try bleeding the system as will need to top up with new coolant anyway.

Again many thanks and hopefully this is easy sorted!

Gentle Ben · Post by **Gentle Ben** » Fri Nov 03, 2006 11:25 pm

Are there any traces of oil in the water or vice versa? Are you losing oil at all?

Air locks a possibility, an easy way to check is to turn the cabin heater on and see how hot the air gets. If it only goes lukewarm then you've an airlock.

Could be anything really, a loose jubilee clip, a deteriorated hose, radiator. Even the water pump or it's gasket!

And congrats on the new arrival ;)