306 Coolant

I've been losing about 500ml of coolant a day now is rather worrying, I took
it down the garage the other day and the guy did a pressure test on the
cooling system to find nada, so he kept the car and said he was gonna do a
gas test the next day (put some chemical into the cooling system to detect
carbon from cumbustion to test of head gasket leakage) well I picked the car
up after the garage was shut yesterday and still don't know the results from
that.

But my main question was how to drain/flush/refill the entire cooling
system?

It explains it quite well in the Haynes manual, but I'm a bit confused about
the refilling with this "header tank" thing?

Any help appreciated

Thanks

 

The header tank is supposedly required because some parts of the
cooling system are above the level of the radiator cap. Consequently,
to be sure you can get coolant into those high levels of the system
you should increase the top-up level. It sounds complicated but it
isn't really. Just take an old 1litre coolant bootle or small soft
drink plastic bottle with a neck which will fit roughly into the top
of the radiator. Doesn't matter if its not a perfect fit - you can use
a rag to make the seal better. Cut the bottom off the bottle so you
can top it up whilst it's inverted, fill with coolant, start the
engine and as it's warming up, keep checking these bleed screws and
let any air out.

As I've mentioned before, I've seen local garages not bother with the
header tank but just do keep topping up the radiator coolant level as
the engine is warming and bleeding.

p.s. regarding you initial problem - have you tried replacing the
radiator cap?

Hope that helps,
Stuart
http://www.radox.freeserve.co.uk/306.htm

 

Thanks!

No I haven't tried replacing the cap, but there's no white crusty mark
around it so I wouldn't of thought that would of been leaking?

The results are in about the head gasket, we have a green light for that! So
thats a weight off my mind.

The garage guy suggested leaving it in a garage over night with some
newspaper underneath it to see if it leaks gradually, I'll have to empty the
garage of all the junk for that one though

There is a bleed screw in the what looks to be the injection chamber? The
big silver thing at the back which looks like it fuels all the
cylinders...that screw appears to be leaking a very very tiny bit, so I'll
get that replaced also.

He also said that the coolant in the coolant system didn't seem to be
circulating to well, so I'm going to bleed and flush the whole system, see
if that helps, because I know it hasn't been done since I've had the car
which is nearly a year now.

However, it might be my water pump! Who knows...

Oliver

 

that bleed screw isnt related to the coolant, thats for the fuel
rail....leave it alone,
if you are losing water there must be a visible leak somewhere, (your not
filling the expansion (header) tank up to the top are you?) the idea of the
header tank is to allow somewhere for the coolant to go when it warms up (it
expands) without it spilling onto the ground. then as it cools down it will
contract and the level will drop.
there is no special requirement for refilling, run the engine from cold with
the coolant topped up, leave the cap off and bleed nipples undone, as soon
as you see coolant instead of air emerge from the bleed nipples replace the
screws.

what engine size do you have?

need to know this to locate your bleed screws if any....some of them are
fitted on the coolant pipes just before they enter the heater matrix in the
car, there is also one on the radiator itself, this one is important as the
air will certainly be trapped in the rad if its not bled out.


hope this helps

 

1.4XL - TU engine sytley lol

I don't understand where there's white stains and visible liquid where this
cap/screw thing is then, I mean I went and bought another one from Peugeot,
and its literally just a cap you hammer in.

Strange, but there is no other visible leaks and as I said a pressure test
and gas test were done. I don't know if this has a bearing on it, but when I
start the car and for a good 5-10 mins till its warmed up there is alot of
white/odourless smoke from the exhaust. More than there should be anyway...

Thanks for the help though!

 

in that case it well could be the head gasket, i guess just because one guy
says it isnt doesnt mean he's right, personally i wouldnt check for head
gasket in this manner anyway.
its not a foolproof way of diagnosis.
you said the bleed nipple (what you thought was the bleed nipple) came from
the fuel rail. if that was the case there isnt any coolant in the fuel rail
is there.

 

sounds like one of the waterways of the head gasket has blown.