coolant woes

Post by **dridgy** » 14 Apr 2007, 13:48

finally finished fitting a polo 1.9 AEF diesel lump and run the van for a few miles.
But
On checking the expansion tank i noticed that the water was bubbling up like it had fairy liquid in it and it was coming out the top of the expansion tank when reved up with the cap off.
This is the same thing that happend to my old 1.6d engine that i thought had blown its head, which is why i replaced it with this new engine.

The temp gauge is also going up about 3/4.
ive beld the water system so its coming out the rad.
the rad is new.
the engine was bought from a garage that assured me it was a good low mileage engine.
i can see no oil in the water.
what should the coolant levels be on expansion tank and top up tank?
anyone got any ideas, before i torch the bloody thing.

cheers
john

Post by **T'Onion** » 14 Apr 2007, 14:04

the expansion tank should be full and the top up ,full to the high line

you did bleed the system with the heater on hot didnt you ?
also expect some air in the system , it has to get hot enough for the thermostat to open

try bleeding it up again , also check all the joint under the van / spare wheel space for leaks (both coolant and air)

you have got the pipes the right way round ie to the rad and from the rad ?

they hold around 16 litres of coolant/water btw

Post by **dridgy** » 14 Apr 2007, 19:50

hi onion thanks for advice.
i did have heater on hot, im pretty sure the hoses are on the right way.
i have stuck a hose pipe in the expansion tank and and opened valve on rad and let the water run through for about ten mins to try and flush out the system.
now there is no coolant in system its just clear water.
i started engine got it up to temp and bled rad again.
when its ticking over theres no bubbles but when you rev it it starts to bubble up but not as much as before i washed out system.
its like theres fairy liquid in the system.
its weird man.

Post by **johncelliot** » 16 Apr 2007, 08:44

I could be wrong about this, but if you have pure water in your system, and you run the van up to temperature, the water will boil. Coolant keeps the water from boiling. I think you need to start the process over again. Drain the water, fill with correct mix of coolant / water. When you bleed the system, top up with correct mix. It will probably take a couple bleeding sessions to get all the air out. Good luck...

JCE

Post by **dridgy** » 16 Apr 2007, 16:42

how much coolant should it take?
i have just bought 5 litres will that be enough?

cheers
john

Post by **johncelliot** » 17 Apr 2007, 08:34

You actually need 9 litres of coolant, which when diluted yeilds enough to fill the system (16-18L). Have a look at this page for more info on the coolant...
http://wiki.80-90.co.uk/index.php/Coola ... ded_brands

Also (if you have not seen it already), have a look at this page for tips on bleeding the system (it is a pain)...

http://wiki.80-90.co.uk/index.php/Coola ... ing_system

cheers,

JCE

Post by **johncelliot** » 17 Apr 2007, 08:38

I just noticed that you have fitted a 1.9 AEF engine, not a standard engine. Your coolant capacity may be different than the 16-18L! Hopefully someone else can let you know how much you need...

JCE

Post by **toomanytoys** » 17 Apr 2007, 09:43

No you dont need anti freeze/coolant to prevent boiling.. only to stop it freezing...
water boils @100c so as long as the pressure cap is ok you shouldnt have a problem..

Amount of coolant/antifreeze depends on what type it is.. some is premixed and has to be used neat, so you would need 17 odd Litres.. or a "concentrate" will have the ratios on the packet

all things being equall.. fill the system and run up to temp.. witht he heater in the hot position.. top up tank should be up to max.. when pressure in the system open the bleeds to let air out..

as the system is a bit of a trap, it might take a week for the rest of any air to come out..
If you seems to have a lot more than a bit trapped here and there, then it sounds like there could be a bigger issue.. check all hoses and connections and maybe do a pressure test..

Post by **Mocki** » 17 Apr 2007, 12:28

bleed it at 2000 rpm when up to temp as well...... it could be a blocked rad, which is common on early dervs iirc

Post by **dridgy** » 17 Apr 2007, 19:19

thanks for all your help guys, i appreciate it.

i have filled with system with 9 litres of coolant and bleed it a couple of times when hot.

seems a lot better now.

ill keep tabs on it.

thanks

John

Post by **Horza** » 18 Apr 2007, 17:46

water boils @100c

At 1 atmosphere it does, doesn't boil til bit higher when under pressure from the likes of a sealed coolant system and a "radiator" cap.

Post by **toomanytoys** » 18 Apr 2007, 17:48

Er thats what I was getting at with "pressure cap" as it isnt realy a radiator cap!!

Post by **Horza** » 18 Apr 2007, 17:55

Sorry "radiator" was a dig at GSF and the like who seem to have missed the point about the engine in the correct end, not at you. Even the VW parts guy called it a radiator cap, wot a nutter.

Post by **toomanytoys** » 18 Apr 2007, 18:03

my 100 was in ref to the comment that "you havent got coolant in there and that raises boiling point" all things being equal.. if your engine is boiling water, then there is a mech fault.. and the 2 degrees (if that) by adding coolant to it to raise the boiling point isnt gonna help..

Yeah they all still call it a rad cap.. but virtually all modern cars dont have a cap on the rad (except the mother in laws Nissan Micra), its allways on the expansion tank..
the term is just like "hoover".... = vacuum cleaner...

Post by **kevtherev** » 18 Apr 2007, 18:07

Oh so I don't have a Dyson hoover.......remarkable