Technical coolant leak

[bollie69]

Ever since I've got the car there has been a small leak of coolant. It appears to be bubling out at the connection of the reservoir return hose and the reservoir itself.
I have had the hose off, checked for any cracks in the pipe of the reservoir, but none. I've tightly secured the hose with a new spanner but still it leaks.

I assume I have filled her up with one litre over the past 1200km.
little Bubles start to come of the hose out as soon as I start the engine and it keeps on leaking long after a warm engine even turned off.

I had the distribution belt, waterpump, aux belt, variator changed 3000km back. Herefor it was just leaking a bit.
I don't have mayonaise in reservoir, no oil, no mayo in filler cap, no white smoke or power loss, and coolant doens't smell like exhaust gasses. SO I don't expect it to be the head gasket.

Shoud I fasten the spanner arround the hose up (could break plastic) or could it be the filler cap that isn't releasing pressure. Is a cooling system always pressurised?

 

[s130]

Cooling system presurises with engine temperature but should always normalise at less that 7psi which is the usual pressure release value of most radiator/header tank caps. Under normal conditions the radiator cap will not pressure relief.

When the car is cold, remove header tank cap and then start the engine. Are there any bubbles emerging up into the tank? The water level may fluctuate and swirl as the engine is reved but hopefully no bubbles will appear. If bubbles do appear then have sniff. Do you smell combustion fumes?

Let the engine run, with cap off till the radiator fan kicks in, periodically checking for bubbles etc. Also do a little reving during this period.

If all is OK let the car cool fully down (preferrably ovenight) and with the tank cap ON. Now watch your hose/tank joint as the car slowly warms up. Does it bubble at the joint very quickly or only starts when the engine water gets warmer? If only when the water temp rises then I would think that it is purely a hose to tank jointing problem.

If this is the case then DON'T tighten any more as you will break something.

If you can, remove the hose and cut 1/2 to 1 inch off the end and refit with a new clip.

 

[bollie69]

I really feared my headgasked on that one.
Thanks for the nice info

I was shure the thermostat was broken because I'm getting so low water temp reading all time. Didn't had this when i drove the 3000km trip from belgium to corsica. We past country's like Luxembourg, France, Swiss and his home country -) Italy....
Here in Belgium the watertemp the needle is staying most time under the first marker for a verry long time. Seems to be good in traffic and in the city, but for semi long distances it's not getting to the right temp. (readout I think)

In my test I let it idle and got it warmed up on the gas.
I've undid the top of the reservoir. No bubbels were seen also when applying throttle. Even with top off the tube was leaking. I'll see I can cut it, maybe i need to buy cutting hardware.

Btw my thermostat seemed to work good in this warm up. The radiator strayed cold until it was fast filled till the water was hot water.
Also the fluid in the reservoir became pretty hot. ... After warming up.
Hehe the thermo works

 

[bollie69]

Btw now the resonator has been removed I can see a small plastic screw on the top of the radiator. Is this for letting air out? to bleed it?
Does the engine need be on so I can see no air is trapped there.

 

[bollie69]

Did a little leak test. Seems the reservor is cracked at the plastic tube, tried to close it with a soldering gun but no luck. Will have to drive to henk in holland to get me a new one. Only €15 Gas €35