406oc.co.uk

Hi hows it goin everyone. I need a little help bleeding the cooling system. I changed the thermostat today and i think the sytem is full of airlocks. Drained the system from the valve at the bottom left hand side of the radiator, and filled the system up afterwards using a good header tank. I searched through the forum to try and find the bleed valves. I followed the advice for tryin to prevent them but the car is heating up very quickly and the heater is still not hot. Oh if its anyhelp the biggest diameter hose that goes from the top of the radiator to the thermostat housing is getting hot and also if i squeeze it this produces bubbles @ the header tank.



These are the places I have bled the system but I have been told that there is one on the thermostat housing. Can anyne tell me where it is or if there are any others.

Cheers.

By "good header tank", i take it you mean something to put the head of the water above the bleed valves? (coke bottle or similar)

Yea i used the 2l milk bottle there in the pic, i ment it was good as it made a good seal with the coolant tank in the car and stood up by itself. lol. The buubles still come up in the coolant tank with out the header on.

Had it out a good 30min journey there and the temp is staying below just 90'C mark but the heater isnt getting hot.

Haynes says l/h end of the engine (it's behind it on my 2.1 ). Haynes also says run the engine at fast idle (>2k) so the waterpump can shove air around, maybe you need to put the heater on full while you're bleeding it too.

Why did you change the thermostat? It's not because the heater wasn't getting hot was it?

Sounds like the thermostat's not opening (you can expect a lot of air in the radiator until that happens). What temperature's the coolant getting to - it should open about 82-89 degrees depending on the model of thermostat (there's a few in 406s)

The method i use is to stuff the hose into the coolant tank until it's spraying out of the bleed valves THEN fit the coke bottle and run the engine for 30 minutes.

You don't use antifreeze?

That goes in before the hosepipe

Cheers for the quick replys.

1. Yes the heater wasnt getting as hot as it used to, so I figured the thermostat was stuck open and I needed a new one. The heater is now a bit warmer but nowhere as hot as it should be.

2. I did notice that the 1st time I got the car up to temperature only the top half of the radiator was piping hot, whilst the the bottom was still cold. I bled it again and the radiator now seems to be hot through out. The coolant temperature isnt rising above the 90 mark and the new stat had 89 printed on it so id guess it must be opening ok.

3. I think im gona have to drain the system again and fill it up using the hose method and then the header tonight.

Il keep use posted.

Got it sorted!! Heater blasting hot air again.

I gave the bleeding another go but this time I roped my brother in to give me a hand. I had the engine running and opened the cap on the expansion tank, next i handed my brother a watering can and told him to keep the tank topped up. So I opened the bleed valve on the pipe connecting to the heater matrix and let the water pour out for a bout 30secs as he kept the tank topped up.

Just need to know now how much antifreeze to put ?