changing coolant....

[delfinis38 1]

just been looking for a quick idiots guide for changing the coolant but found nothing.... anyone like to point me in the right direction or give me an quick guide how to flush and change, I've got air co if that makes any difference...... got an idea what I plan to do just need a push in the right direction.

 

G12++ or G13.... not found the correct answer either for a VR6

[davidwort 0]

there's not really any magic to changing coolant, drain from the lowest accessible hose joint and fill slowly from the header tank run to temp and top up as needed.

any red/purple modern coolant additive suitable for alloy and iron components will do fine, or you can get obsessed about various spec VW fluids, none of which were around when the VR6 was designed :)

 

I'd advise using distilled water rather than tap water though, especially if you live in a hard water area.

[seanl82 23]

Its worth back flushing with a hose as much as possible too. It'll help rid some of the crud that will have built up over time in waterways. No one ever remembers the heater matrix either, so disconnect the hoses and flush that through too. As mentioned top up slowly, and leave the expansion cap off when you run it up. Massage the hoses to help push any air pockets up and out. I rev to 2.5k rpm for 30 seconds, then let it idle and massage hoses for 30 seconds at a time. It takes a while to do it all, but I've never had any problems with air in the system afterward. Once up to temperature, shut off and top up as necessary once its cooled.

[delfinis38 1]

Hadn't thought about back flushing the matrix. Couldn't find the coolant drain tap that Bentley mentioned so was going to dump it from the bottom of the rad. Flush the rad from the top then connect pipes and fill with distilled water wake the heater on full and run for a bit making sure it doesn't overheat. Then dump the water a fill with a mix of coolant and distilled water. It's got orig coolant in it so I guess it needs a good flush.

[Jon_vr6 1]

Theres a drain plug on the crack pipe under the car but as you said it is a pain to see. A top tip to avoid air locks is to NOT fill from the expansion tank first but to get a funnel into the top radiator pipe and fill from there until you see fluid in the expansion tank. Then connect and clamp off the top rad pipe to the radiator elbow as you would and fill the rest from the expansion tank. As others have said leave the expansion tank cap off for a bit whilst the engines running just not too long, take for a spin let it cool afterwards and top up again if needed

[delfinis38 1]

Theres a drain plug on the crack pipe under the car but as you said it is a pain to see. A top tip to avoid air locks is to NOT fill from the expansion tank first but to get a funnel into the top radiator pipe and fill from there until you see fluid in the expansion tank. Then connect and clamp off the top rad pipe to the radiator elbow as you would and fill the rest from the expansion tank. As others have said leave the expansion tank cap off for a bit whilst the engines running just not too long, take for a spin let it cool afterwards and top up again if needed

 

Thanks great advice.... Re filling.....

 

Now which coolant and what mix 50/50 ?

[mr.ots 10]

I used G13+ at 50/50

[seanl82 23]

G12++ or G13 will do fine. Around 6 litres in the system, so 2 x 1.5L bottles of coolant is perfect for a 50:50 mix and good level of anti-freeze down to temps far below what we're likely to see in the UK.

[delfinis38 1]

G12++ or G13 will do fine. Around 6 litres in the system, so 2 x 1.5L bottles of coolant is perfect for a 50:50 mix and good level of anti-freeze down to temps far below what we're likely to see in the UK.

 

Cheers... Book says 8.2/8.6 with air con. So I guess 3 bottles of g13

 

Does the air co effect how the system is bleed / flushed / filled.

[delfinis38 1]

Oops sorry guys. Wrong section should be in engine bay not drive train.

[delfinis38 1]

Cheers... Book says 8.2/8.6 with air con. So I guess 3 bottles of g13

 

Does the air co effect how the system is bleed / flushed / filled.

 

Anyone . Before I get to involved this morning.

[VAG-hag 0]

Surely the air con is a different system, or do you mean with regard to access?

[delfinis38 1]

Surely the air con is a different system, or do you mean with regard to access?

 

Dunno now. The book suggests with air co it takes 2 litres more coolant than the standard 6 litres

[Dox 23]

Dunno now. The book suggests with air co it takes 2 litres more coolant than the standard 6 litres

 

The Bentley is aimed at cars in the USA, you may find they fit a larger rad with aircon as the aircon rad sits in front of the coolant rad reducing the airflow or heating the air about to go through the coolant rad if the aircon is in use

[Sean_Jaymo 0]

I'm sure most cars (not sure on Corrados) the radiator is bigger to accommodate the extra heat generated by the aircon radiator that is bolted in front of the coolant radiator. Are Corrados with aircon equipped with thicker radiators?

[Goldie 2]

I think my old Corrados rad was the same thickness..

 

I personally wouldn't put as much coolant in as a 50/50 mix, the coolant doesn't cool a effectively as water.. We aren't subject to mega harsh winters here either.

[Dan_Storm 0]

I'm pretty certain there is no difference in the radiator sizes on UK Corrado's with aircon. I changed my radiator last year with a Hella unit and it was the same size as the original. The only difference I am aware of is that aircon radiators have a couple of brackets screwed in to hold the condenser in place.

[Sean_Jaymo 0]

In that case, there is nowhere else you can physically fit another 2l of coolant.

 

I've just seen Doxs post, that's what I mean. US Corrados must be different to GB versions.

[mr.ots 10]

Don't forget, in the UK the aircon was effectively an aftermarket fit whereas in the US it was probably a standard fitment so may have been engineered differently.

[delfinis38 1]

Okay... so I've drained it and flushed it a few times this morning, wasent too mucky apart from some sludge at the bottom on the expansion tank that I cleaned out with a rag and a screwdriver.....

 

looks like the bentley was wrong not 8 litres, I filled the system with about 6.5 litres of water to flush it.

 

next weekend I will fill the system up.... just ordered some G13 of ebay.

 

any suggestion on mix 50:50 60:40....

 

was thinking as its about 6.5 litres I need to put 3 litres of G13 concentrate in and fill the rest with iron water. so its in between the ratio.

 

anyone know if the coolant drain plug on the crack pipe is still available to buy from VW....

 

might buy one for next time it has a part number of BPO 021 121 100

Edited February 9, 2014 by delfinis38

[delfinis38 1]

put new coolant in this morning. with a new coolant drain plug which I bought from VW.

 

all seem okay.... can anyone tell me what temp the fan should kick in at on a VR6.... mines at about 98 degrees. is that about right ???

[VAG-hag 0]

Okay... so I've drained it and flushed it a few times this morning, wasent too mucky apart from some sludge at the bottom on the expansion tank that I cleaned out with a rag and a screwdriver.....

 

looks like the bentley was wrong not 8 litres, I filled the system with about 6.5 litres of water to flush it.

 

next weekend I will fill the system up.... just ordered some G13 of ebay.

 

any suggestion on mix 50:50 60:40....

 

was thinking as its about 6.5 litres I need to put 3 litres of G13 concentrate in and fill the rest with iron water. so its in between the ratio.

 

anyone know if the coolant drain plug on the crack pipe is still available to buy from VW....

 

might buy one for next time it has a part number of BPO 021 121 100

 

It holds 8+ litres but some will remain in the block when you drain the system :-)

[Roger Blassberg 0]

Have a look in the Definitive Cooling Guide sticky at the top of the Engine Bay section; it gives all the fan cut-in/cut-out temperatures and a good troubleshooting guide if things aren't doing as they should.

 

RB