About to flush coolant / thermoswitch replacement

[radness 0]

Hey guys,

 

I'm about to replace the thermo switch on my corrado 16v 9a as it's gone.

 

I looked in the coolant tank and can see a few bits floating about, i also know that once i remove this switch that coolant is going to gush out.

 

My plan now is to drain the coolant completely and then replace the thermo switch then replace with the coolant i purchased today from halfords(i know i know but vw service centers are miles away from me and i did a bit of reading and i hear this pink coolant is pretty much the same as g12).

 

I think i have just plain water in my coolant system at the moment :(

 

Ok enough rambling my questions are this;

 

1. Can someone please post a pictureo f the hose i need to disconnect from the bottom of the radiator? I assume it's on the passenger side from what i've found using the search feature, but if you have a picture i'd GREALY appreciate it :)

 

2. Do i simply remove the thermo switch with a spanner or is there more to it?

 

3. I read the guide in reference to flushing coolant, is it ok to just leave the drain off and run the hose into the system while it idles? Will the cold not be bad for it?

 

4. Is there anything else i should be careful of? I'm a complete noob :)

[JMC 0]

Well, for number 2, that is basically it. Unscrew the old one and screw a new one in (its a 27mm spanner I think). Did mine yesterday, so it is still fresh on my mind 8) . Sorry, but not sure about the rest, although I am sure someone else will be along to help you there.

[radness 0]

Well, for number 2, that is basically it. Unscrew the old one and screw a new one in (its a 27mm spanner I think). Did mine yesterday, so it is still fresh on my mind 8) . Sorry, but not sure about the rest, although I am sure someone else will be along to help you there.

 

 

Thanks for the response will let you know how it goes :)

[dirtytorque 0]

Just drained mine a couple of hours ago.

I think you have the same hoses on a valver ?!? :scratch:

bottom left hand corner is the thermostat housing.

[davidwort 0]

I've done this a fair few times on valvers now and there's a few things to be aware of.

firstly, it's better to get a fibre mk2 golf rad switch washer from VW (part no. N 043 808 3 about a quid) as they tend to seal better than the metal washer the new switches sometimes come with, it has to seal against the plastic of the radiator and the metal washers just don't have enough give.

 

I'd drain the water into a pan/bucket and see how much sludge/dirty water comes out, if it's pretty mucky then it's an idea to drain it fully, for this you need to remove the power steering pump bracket mounted to the bottom of the engine block and remove the plastic elbow and thermostat from the water pump, otherwise loads of coolant will stay in the block as the thermostat will be shut stopping the flow.

You could remove another water hose at the front of the block but a) they're poretty inaccessible and b) you probably leave some water in the pump and block this way.

You might as well change the thermostat while you're at it(and o ring seal) only a few quid and genuine VAG is a good plan.

I'd then put it all back together, fill with tap water, run until hot (in fact you could leave the stat out to do this) and then drain it all down again.

then fit the new stat, and refill the coolant with 50/50 or 60/40 distilled water(battery top up water - halfords?) and antifeeze.

When you re-fill you need to do it very slowly from the header tank, this way you're least likely to get an air lock in the head, a 2L coke bottle with a hole drilled in the cap can do this for you! rather than getting aching arms.

From dry the system needs 6.5 Litres of coolant in total.

you don't need to have the heater on in the car as there is no valve in the system, hot water always runs through the cabin heater matrix, the heating control is just done with air flaps.

 

This all sounds a bit involved but will get everything cleanest, however you could just drain what you can from the bottom rad hose and then top back up, run till the stat opens and then drain again, at least you'll get it cleaner than it was even if you don't flush it perfectly.

[radness 0]

I'm an idiot, i forgot the pipe is on the passenger side. Got a bit confused when i saw your picture hehe

 

Anyway, i've gone and disconnected a pipe i know nothing about (not smart) :cuckoo:

 

I don't know why i honestly disconnected it because it was pretty stone cold, cars been sitting over an hour now, but the block and other radiator pipes are warm....

 

anyway, disconnected it and a lot of oily looking stuff came out into my basin, smells a bit like fish...hehe

 

can anyone tell me what i've done? have i drained my power steering or brake fluid? how can i fix this? What damage have i caused, air locks..etc? I quickly put it back on but it seems there was not a lot in there to come out as it'd pretty much finished dripping out when i was thinking "wtf have i just done"....

[radness 0]

I think i've just worked out that it's the power steering pipe i've disconnected, is that right?

 

I've checked the fluid level and it's just a little bit below the "min" mark, is it safe to drive it like this? will i have caused any air locks or anything? And one last question , what do i need to top it up with? obviously power steering fluid but which type/brand?

 

The piping for the radiator that i need to remove requires a special tool to remove the clip or is there some fancy way of doing it that im unaware of?

[davidwort 0]

you can get PS fluid from GSF FEBI stuff in 1L plastic bottles, it's the green type of fluid, basically LHM citroen hydraulic suspension fluid, as long as you buy green stuff and not red ATF fluid, it should be fine.

 

the hose clips can be removed with a pair of mole grips or one of those adjustable jaw plier things.

[radness 0]

Hi guys, always nice to update everyone once i use your advice (or not use) :tongue:

 

After messing up and disconnecting the wrong pipe i stressed a bit and it was getting dark so I didn't do the full clean of the system as suggested , although i would have liked to if i had the time.

 

I'm not too sure if this is at all recommended but i drained the coolant the best i could with the thermo switch out(wasn't sure if i would been able to reconnet the radiator hoses), ran water from the garden hose through it till it started running clear, it wasn't really as dirty as i though but the color of the water was pretty bad.

 

Put the old thermo switch back in (didn't want the terminals of the new one getting wet) filled up the coolant expansion tank to max with water, left cap off and let the engine idle until it hit the 90c mark and the lower coolant pipe got hot (very obvious as the water started boiling out of the tank) turned engine off, i took out the old thermo switch out and pretty much no water came out....wtf? a lot did boil out of the expansion tank but still doesn't account for all the water i'd previously put in? hmm.... The expansion tank is empty...

 

Anyway, i topped up the level again to max , let the engine run until 90c then when the thermo switch opened it bubbled over again like before and taking all the water/coolant with it, while the switch was open i filled it with 50/50 , put 4-5 liters in so im guessing there is still some old coolant in there that davidwort's technique would've got out. :lol:

 

I'm not sure what i've done, but what i do know is that i put a lot of coolant in and the expansion tank looks a bit cleaner!

 

With the new thermo switch in my corrado sits around 80-85C coolant and 106 oil (when sitting parked) 100 (when driving), im happy as it used to go upto about 120c oil / 110c water when sitting. :)

[JMC 0]

Good to hear you got it sorted. Out of interest which thermoswitch are you using (do you have a part number) as I'm looking for something that would keep it around there. The standard ones sit higher than that, and the low temp ones seems to kick in much too early, 80-85 is a good happy medium.

[radness 0]

Out of interest which thermoswitch are you using (do you have a part number)

I'll see if i can pull the part number out, i got it from ECP, they sell a few for the corrado i got the one with all three pins in a perfect line (some have 2 pins lower and one pin above, or pins in a triangler formation). Mine did come with a copper washer, so it might be best to do as davidwort suggested and get yourself a fibre washer for a better seal. :salute:

[davidwort 0]

copper is better than the sprung steel ones GSF seem to have on theirs, it may be fine, but I had trouble on mine, just an annoying small amount of weeping with the metal washer

[JMC 0]

Out of interest which thermoswitch are you using (do you have a part number)

I'll see if i can pull the part number out, i got it from ECP, they sell a few for the corrado i got the one with all three pins in a perfect line (some have 2 pins lower and one pin above, or pins in a triangler formation). Mine did come with a copper washer, so it might be best to do as davidwort suggested and get yourself a fibre washer for a better seal. :salute:

 

Cool, that would be great, and thanks for the advice on the fibre washer :)