Help needed! Changed coolant on my C, now have fountain?!

[Jay2 0]

Help urgently needed!

 

Changed the coolant in my 1991 G60 Corrado today, as it had changed to a strong Tea colour. Usual, "oh, easy afternoon job on the car". :twisted:

 

Took off the bottom hose, drained it, flushed it by removing the top pipe and pouring water through the radiator. Cleaned the expansion tank out too. All after double checking with the Bentley's manual.

 

Plumbed it all back together, refilled with a water/coolant mixture, no leaks.

 

Started the car up and left running with heaters on max. Next thing I know most of my coolant is running down the drive. Seems to be boiling up and p*ssing out of the side of my expansion tank through, what I presume is an overflow hole, located on the right hand side, behind a plastic cover next to the strut top.

 

As it was popping and fizzing, presumed it was air trapped in the system.

 

So let it settle down, topped it up and started the process again, left the car running to get to temp and left it popping and spilling out coolant.

 

Did this for most of the afternoon without any luck or progress.

 

Then the water warning light comes on on the dashboard, (the water temp gauge rises to around 70 while stood and 80 while being driven around the block but no further, so not overheating?), and the coolant still seems to boil up into the expansion tank and then through the side overflow hole. If you turn the car off and let it cool the coolant drops off to normal.

 

What am I missing, as its baffled both me and my mate?

 

Do the water coolant sensors detect the pressure in the system and that's whats setting the water warning light off?

 

Surely I still can't have air trapped in the system?

 

What else could cause the coolant to boil and rise up so violently?

 

Using Halfords coolant that's recomended for my C, could this be the problem, that is not of a high enough grade, causing the system to boil up?

 

:shock:

 

Any suggestions greatly and urgently needed!

[Tempest 0]

The way I normally refill the system is through the reservoir, but then as soon as I start the engine, I actually with the reservoir cap still off start squeezing the top hose leading to the rad, to get rid of any air bubbles, which then indeed start to bubble up and escape through the reservoir.

 

In doing so don't let the coolant temperature reach 100°C, as that's when the stuff starts to boil over, hence the need for the pressure cap on your reservoir to increase the boiling point above 100°C.

 

Tempest

[Supercharged 2]

The caps failed i think - get a new one (should be blue)

 

Try it first but I would refill with G12+ when you get a chance - it's what VW recommend and not expensive...

 

As above fill (slowly - 5mins) via the tank and then stant the engine up with the cap off, run it up to 50 degrees or so then screw the cap down.

[Neil VR6 0]

Wasn't there a recall on the black caps?

[craigowl 0]

I have always squeezed top hoses vigorously several times :oops: and have never had air locks in 30 years of coolant changes.

[Jay2 0]

Thanks for all the suggestions.

 

Left the car to settle overnight.

 

Topped up and ran the engine again this evening.

 

Again got the flashing warning light on the dash and once warm I get the usual steam, gushing coolant from the tank. How much air can get trapped?!

 

Got a blue cap on the expansion tank.

 

So the conclusion is to get some decent G12+ coolant and redo the job again, taking my time to fill the system up and then running up to temp gently, while squeezing my hose? :oops:

[willg95vr6 0]

I had the same issue on my c vr6, the t piece pipe coming from the top of the expansion tank then branching one way to the top of the radiator and the other way in the direction of the accelerator cable - was block between the radiator and the t piece.

 

resolution was to push a steel coat hanger gently through.

 

sorry i am rubbish at explaining parts

[mattkh 0]

Help urgently needed!Using Halfords coolant that's recomended for my C, could this be the problem,

Any suggestions greatly and urgently needed!

 

Hi

 

Do you know what coolant was in the engine before ?

 

When it boils, are both the top and bottom rad hoses the same temperature ?

[mr.ots 10]

I changed my coolant recently for some new G12+ but filled the system via the top hose (at the Rad end) until the coolant rose into the expansion tank and then reconnected the top hose, ran the car up to temp and then topped up the expansion tank. Doing it this way prevents any airlocks. Car is running cooler too!

[Jay2 0]

Coolant had been in since buying the car about 8 months ago. So not sure what was in.

 

Yep, all the hoses get warm/hot, as checked for leaks while it was running.

 

Would air in the system set the warning light off though??

 

Can I get G12+ anywhere or have to go to the dealers/GSF, etc?

[_Tony_ 0]

Is the radiator fan kicking in before it drops its coolant?

[Foggystorm 0]

I got G12+ from the local stealer for £4.82 for a 1 litre bottle (thats with 10% discount)

[craigowl 0]

AS Foggystorm suggests, dealer is best place for G12+, and unlike many items they have, the cost is reasonable.

[Jay2 0]

Cheers for the info on cost for G12+, will be on my way to the stealers as soon as I can get a lift and time from work.

 

The fan does kick in eventually, which then cools everything down and the coolant drops and stops bubbling. But then as soon as the fan stops it hots up again and starts bubbling and p*ssing out of the coolant tank.

 

Thanks for all the advice, as missing being able to drive my C.

[Guest]

bypass the rad fan switch to make sure the fans are working run the engine again but make sure both big pipes connecting to the rad get hot if one is cooler then you may have a problem with the thermostat if the fans dont kick in the you may have a faulty fan switch good luck

[willg95vr6 0]

I do have to say i stil have the exact problem as you, i thought i fixed it but i didn't. the coolant loss is just before the fan kicks in for me and yes both pipes are hot (lower one gets hot when the thermostat kicks in)

 

Can any one help us

 

ps someone a my work reckons it is a massive airlock

[craigowl 0]

Does the gas and bubbling from the coolant reservoir smell of petrol fumes?

(Watch your beak - don't get it scalded!) A garage can stick a probe into the gas and tell you whether there are exhaust fumes there. (There should not be.)

 

Are there any oily droplets/scum swirling around in the coolant reservoir and sticking to the sides of the container?

 

Do you have mayonnaise on the oil filler cap before the cold engine gets up to working temperature?

 

When you look at the oil dipstick after carefully lifting it out, can you see any watery droplets sitting on the oily surface?

 

If yes to one or more, sadly, the head gasket has almost certainly sprung a leak.

 

Good luck with your investigations, anyway, guys.

[willg95vr6 0]

unfortunately no to all the above,

coolant is as it should be pink none oily

oil clear golden-ish no bubbles.

Water doesn't seem to smell of exhaust fumes

coolant seems to bubble up only just before the fan cuts in a just after the thermo swiches over.

 

i am going to take it

[willg95vr6 0]

* to the garage me thinks (again)

[Jay2 0]

Hello mate, yep given in as well with my problem, booked into garage next week for them to pressure test, then take it from there.

 

Had another session on Sunday, drained it and refilled a couple of times to make sure it wasn't an air lock.

 

Still got same problem, but starting to think that its the Thermostat switch, as the bottom hose that goes to it stays cool sum of the time. Looked at where it is, and thought bugger that, ring the garage.

 

Will keep you updated. Fingers crossed its not the head gasket!

[Tempest 0]

Looked at where it is, and thought bugger that, ring the garage.

 

It can be done, it's a bit uncomfortable to access, but I've done it. Easier, of course when the whole rad is out :-)

 

Tempest

[Jay2 0]

Got Corrado back today from local VW specialist, problem sorted!

 

The guys did all the regular checks, pressure tested the system, checked all the hoses, sensors, rad fan and thermostat. All fine.

 

So the next thing was obviuosly head gasket. :shock:

 

But then inspiration came and they tested the expansion cap and...........yep, a bit of the rubber seal in the cap had got pushed-up causing it not to seal properly. Really need eagle eyes to see it but the small crimp is definately there. Problem solved with a £7 new cap :D plus labour and testing fee's :roll: . But I'll take £50 over a new head gasket anyday!

 

Drove car home, no steam, overheating or flashing warning lights. :lol:

[mattkh 0]

Got Corrado back today from local VW specialist, problem sorted!

 

Problem solved with a £7 new cap :lol:

 

Really happy for you.

What color is the new cap

[Jay2 0]

Nice shiny blue one.

 

Cheers.

[willg95vr6 0]

how jealous am i, i have already got a new cap and tank, but still the same problem ;( car goes in on the 7th march. the good news is i have just bought a brand new golf gti 30th anniversary