206 coolant level

[Toby_HDi]

I've been working on my partners 206. Its a 1.4 8v TU3JP (KFW)

It had developed a leak from the thermostat housing (all plastic on this one) due to it being warped. Luckily it was the bit which comes with a new thermostat. Changed this, flushed the system and refilled. I'm now concerned that 3 days later I am still having to top up the coolant. Its been checked every day and is always down. Just residual air being pushed out? There is only one bleed screw on this car, rad has been replaced in the past with one without methinks. Seems not to be one near the thermostat either. Only one on this is in the matrix pipe. Bled the air out this one fine then tightened up. Should I have used a header tank? Didn't feel the need as the reservoir is the highest point in the system. I've since checked for leaks but all is bone dry.

Have I missed something?

[addo]

Have you not got the bleed screw on the metal part just before your thermostat housing? It's not always very obvious.

P.S. 1.4 = oil in coolant. :/

[citronut]

probably depends on the year of the car to if it has/had any other bleed screws,

the new the car it probably self bleeds back to the tank via a thin hose from the top corner of the rad,

rad/tank caps are a known failing point on the small cit's and pug's,

i would run it up for a while with the cap off, at least till the thermostat has opened, then any air in the system should disperse through the open cap, the coolant level should then drop at this point so keep topping up as required,

dont run it to long with the cap of as once the temperature starts to rise it will probably erupt

[spider]

What I used to do on these (and most TU engines that had a round tank, round tank only!) was to unhook it and lift it up a bit so it was higher than everything else. One of those exhaust Z shaped bits of metal ideal to hook it. 205/206 thing only really then.

There should be a bleed on the thermostat housing as said and highly likely one on the heater hose near the bulkhead at least. I think 206's don't have one on the rad as well though.

[Toby_HDi]

I had indeed missed something. The thermostat bleed screw. It is slightly recessed and has a flat blade head, not something I was looking for first time round. I opened it and no air came out.

I gently lifted the tank too and again got no more discernible air. The car doesn't overheat and heater works fine. The cap is a little gunked up so I might just change it for the sake of £3.

The car is 2005 and does indeed have a small hose running back to the tank from the top of the rad.

I've heard the stories of the 1.4 oil in coolant problems. This one had the head gasket go a couple of years back and that was why I drained and flushed rather than just replace the stat. The tank was full of gunge until I cleaned it out.

[spider]

It may be a plastic tyre type cap or it may have a small brass hex, if its the latter (cold engine only!) remove it as it can clog. I always used to remove them rather than unscrew two turns etc to be sure.

If in doubt as you say change the cap itself.

Just leave the bottle high up and without the engine running open the thermostat bleed (again, cold engine) and after a few moments hopefully something will come out.

Take exteme care if its a brass screw as they will snap off, a tiny tweak (little finger only pressure) is all that's needed to secure them air and water tight.

I think early ones are brass later have the plastic thermostat housing affair with the bleed next to it as you're describing.

[Toby_HDi]

I've got all I can get out the bleed screws. Is just coolant coming through now. Unless I'm supposed to leave them open for longer than I have been.

Or is it just a case of I now just keep topping up with coolant every day until all the air has purged itself?

[spider]

Generally once it stops bubbling is fine. This can be a couple of seconds to about 30 seconds (if you're unlucky) no longer generally.

Sometimes (although usual precautions against hot steam or water!) I would loosen them after a minute or two of running to verify it has all been purged.

Leave the cap off the expansion bottle while bleeding and initially running it too.

[Toby_HDi]

As I thought, in which case I do hope that flushing the system hasn't disturbed anything internally that was actually preventing a leak.

[spider]

Shouldn't do really to be honest, if it did whatever you did would only catch you out probably somewhere inconvenient...

If it continually foams (as in proper foam rather than bubbles) its usually a sign an excess or radweld or suchlike has been used but not always.

If you're sure you've got coolant from each bleed now, just make sure the bottle is up to the max mark (not overfull!) and keep an eye on it. It should not really go anywhere.

[Toby_HDi]

Thanks spider. Will keep an eye on it. Hopefully eventually I'll stop needing to top up.

[Toby_HDi]

Just to conclude this, after a few more days the level remained where it should be. Seems what was left in there worked its way out. Now just to give it a bit of service