coolant levels,

[syncro4us]

Have been running our rebuilt 2.1  engine for some time with over 2000 KM on the clock so its well run in, so this summer took it to the Pyrenees and had a great time except the weather was extremely hot for Sep/Oct but cooled off now.
Generally the temp guage needle rests with the bottom edge of the needle just into the top circle of the  red led but not lit, low coolant warning light circle as normal running temp having fitted the new Go-Westy digital PCB from Brickworks which works well to provide this normal running condition 

After returning to the UK Having re bled the system to check for any  air pockets the VW is running well with no effects on coolant levels when cool and no change to the main tank when hot so everything is normal when cold or hot.
So continuing with circuits to check all is still ok after going round and tightening all hose clips on engine and those on the stainless pipework underneath etc and the guage and coolant levels are absolutely normal despite some of the hills we climbed so all's well.



 

[AIR_CHILLED]

Good luck with your fault finding.

My engine has been using a bit of coolant for years and I could not figure out where the loss was coming from until I discovered the heater under the rear seat was leaking. There is a O-ring on the shut off valve, mine was leaking from there and going under the flooring and therefore going undetected. 

[Cecil]

I bought 2 Blau “dalek” caps from our favourite supplier one of which seemed to be good but the other one had the black part unsecured to the blue part though it did not readily fall out. I think it should have been plastic welded together in order to make the blue plastic to black plastic joint air tight.So I think your problem might be an air leak there or possibly in the pipe to the top up tank preventing coolant being sucked from the top up tank to the header tank.
I think I might also undo the “ dalek “cap once the engine has cooled after a run and try to establish if any hiss of air is suction and and not pressure .My thinking being if there is still pressure there then the head seals are suspect.

[Simon Baxter]

I bought 2 Blau “dalek” caps from our favourite supplier one of which seemed to be good but the other one had the black part unsecured to the blue part though it did not readily fall out. I think it should have been plastic welded together in order to make the blue plastic to black plastic joint air tight.So I think your problem might be an air leak there or possibly in the pipe to the top up tank preventing coolant being sucked from the top up tank to the header tank.
I think I might also undo the “ dalek “cap once the engine has cooled after a run and try to establish if any hiss of air is suction and and not pressure .My thinking being if there is still pressure there then the head seals are suspect.

They are simply a press fit, they are not "unsecured", that's how they are they need to be screwed down to a header tank for them to seal.
Thats why you can't trst them unless they are attached to something as you need the pressure of the neck to push them home.


 

[Simon Baxter]

Have been running our rebuilt 2.1  engine for some time with over 2000 KM on the clock so well run in so this summer took it to the Pyrenees.
Generally the temp guage needle rests with the bottom edge of the needle just into the top circle of the red low coolant warning light as normal temp.
(I fitted a new digital PCB from Brickworks and this is the running condition.)

Everything has been fine and steady whatever the conditions till after taking it up to a ski center we visited in  our T2 in 2005 via 1:3 type grades with sharp bends to about 3000-4000ft.
After this I noticed the header (HP) tank had a bubble in it whereas before it was always full to the top after bleeding it some time ago.
The overflow tank seemed to get very low so topped it up to make sure any coolant leak was replaced.
So far
1)I have been around the jubilee clips to knip them up
2) started the engine with the blue pressure cap off to see if there are exhaust gasses there but nothing and no bubbles and have replaced the cap with a new one
3) re-bled the system via the thermostat housing and radiator to make sure there were no air pockets
4) even checked the torque of  4 of the accessable head nuts and they were perfect at 35lb ft
So am going on a run tomorrow to see how it behaves.

On our old engine now in our garage I swore by K Seal but that engine had done about 350,000km this one is just touching the 3,200KM mark and I dont want to use K seal on a newly rebuilt engine with only 3000 odd KM that might mask a problem.
I am hoping that the roads in the pyrenees didnt over stress the engine which has the right SPG Bilstein orange coolant and a new radiator pipes and thermostat etc from Brickworks.
Cant quite figure why the bubble keeps appearing in the header tank but will see what happens tomorrow.
Incidentally the temperatures in the Pyrenees have been about 28-35 celcius even at 3-4000ft altitude but in the north  its suddenly chaged to Autum mode now e are back in Calvados

any ideas welcome as I had really thought the recon/rebuilt 2.1 engine would have solved all our previous engine over heating (which it more or less does with the needle slightly higher eg in a traffic jam or idle when the 2 stage fan come on) and bubble in the header tank behaviour which I thought might be due to air sucking back through a loose hose clip but nothing obvious to see .
also Timing spot on
Hydraulic tappets were ajusted as per Haynes and engine runs sweet.
we made sure that in the Pyrnees especially on steep roads we ran on petrol which burns cooler so not an LPG issue
Otherwise the VW sings along with no loss of cooland via the exhaust

Is the level in the overflow tank rising? does coolant spill out when you take the cap off?

[Stesaw]

Might just be that with the hills there was still a bit of air in the system that's made it's way to the back.

Just top up both tanks and as Simon says (no pun intended) make sure the overflow tank behind the numberplate flap isn't pushing coolant out the top.