Another 16v cooling dilemma

[n3p 3]

Hi guys, sorry if this is a bit long

 

I've recently replaced both water flanges after discovering a couple of small leaks causing the engine to overheat. Simple enough job, and all had seemed fine. I've only driven the car about 20 miles since i've replaced them and on these occasions the engine hadn't overheated. Took it for a 20-30 min spin this morning just to see for sure if all was well, but had noticed a couple of things..

 

Firstly, the car didn't overheat but when i parked up the fan didn't turn on, so i'm not sure what that's all about. Secondly, the top radiator hose felt very pressurised and solid, and from what i could reach the bottom hose felt quite hard too (didn't check the heater matrix hose).

 

I know that these two symptoms have been covered upon searching, but i was wondering how much current was required to kickstart the fan, because i currently have a knackered alternator (waiting on a replacement to arrive) and can only drive for small periods at a time, i've been trickle charging inbetween just so i can enjoy the car for a little bit :nuts: . I tested the battery before i set off and it read around 11.68v with the engine running. Would this also have any affect on the fan? How about the rad hoses or is that a different problem altogether?

 

Ordered a blue expansion cap, thinking about changing the thermostat as i'm not sure when it was last done and i've yet to test the water pump but the car doesn't overheat...i'm just thinking that if i had driven it for longer the pressure could have burst my radiator hoses? Any thoughts?

 

Last question...upon searching people have been advised to buy a rad fan switch - where can i get one of these? part numbers would be great

 

Thanks! :salute:

[Jim 2]

Hmm... sounds like an airlock to me? Did you run the engine up to temperature with the expansion cap off? Also helps to squeeze the top and bottom radiator hoses whilst doing this to help 'burp' it...

 

Get the rad fan switch from Volkswagen - when changing it, you need a new sealing washer. I don't think it comes with one, and the ETKA system doesn't even show one for the Corrado I don't think. Get the guy to go onto the MK2 Golf catalogue on ETKA instead and he should see in the same section a sealing washer which is only pennies - it's made from a sort of fabric / sponge with a sticky back which you stick onto the rad fan switch before you screw it into the rad :)

[n3p 3]

Thanks for the reply Jim :luvlove:

 

Forgot to mention, i did this last night :salute:

 

And i guess i'll have to wait until tuesday before i can order a new switch ¬_¬ Thanks for the heads up about the seal, i'll be sure to get the guy to check the Mk2 list, although they're usually arses and say "registration number?"

[n3p 3]

Also, if anyone knows a way to test the existing rad fan switch it may be handy..weather is nice could work on the car :norty:

[RaddoMan 0]

messure the ohms?

[n3p 3]

Which resistance should i be measuring? Sorry - my electrical knowledge is well, crap!

 

Another thing, I've just realised that VW will probably take ages to get the part in and don't take orders over the phone which is quite sh;t as i work in central London and i really need the car to work by the weekend. I've been on vwspares.co.uk

 

http://www.vwspares.co.uk/corrado_cooling.php

 

Can anyone tell me which one is for the 16v radiator? I think its the first one, but if someone could confirm that would be great 8) Cheers!

 

**EDIT: just seen the date ranges for the two switches, ignore me!***

[davidwort 0]

you can test the radiator fan switch, but you need to take it off the car, which unfortunately means draining your coolant really.

bit crude, but this is what I did:

if you have it off the car, the three pins consist of a common earth (can't remember which pin but look at the wiring to the connector block for that (brown))

 

and then the two speed circuits

 

if you connect a test light or multimeter up in continuity or resistance test position, neither path (earth to speed 1 or earth and speed 2) should be closed, i.e. a circuit through when it's at cold/room/air temp

 

heat over a candle or gently over a low gas hob, and you'll hear the circuits click shut, don't go too mad heating them as you only need to get to about 95 and 105 degrees.

 

repeat for each of the circuit paths (speed one and speed 2)

 

first speed should audibly click when it goes ON when heated and the circuit makes, speed 2 will follow a few seconds later as it's a few degrees higher

they should close one at a time as you let it cool down off the flame, multimeter just proves the circuit completes.

 

obviously heat gently as you don't want to melt the thing, and hold it in some mole grips rather than burning your fingers :)

 

the switches are designed to open on cooling at a different temp to closing and switching ON, to stop the fan contantly cutting in and out, I've got a fancy laser pointer IR thermometer which just confirms the temps, but 10 secs (roughly) under a flame is enough to heat to about 100

[n3p 3]

you can test the radiator fan switch, but you need to take it off the car, which unfortunately means raining your coolant really.

bit crude, but this is what I did:

if you have it off the car, the three pins consist of a common earth (can't remember which pin but look at the wiring to the connector block for that (brown))

 

and then the two speed circuits

 

if you connect a test light or multimeter up in continuity or resistance test position, neither path (earth to speed 1 or earth and speed 2) should be closed, i.e. a circuit through when it's at cold/room/air temp

 

heat over a candle or gently over a low gas hob, and you'll hear the circuits click shut, don't go too mad heating them as you only need to get to about 95 and 105 degrees.

 

repeat for each of the circuit paths (speed one and speed 2)

 

first speed should audibly click when it goes ON when heated and the circuit makes, speed 2 will follow a few seconds later as it's a few degrees higher

they should close one at a time as you let it cool down off the flame, multimeter just proves the circuit completes.

 

obviously heat gently as you don't want to melt the thing, and hold it in some mole grips rather than burning your fingers :)

 

the switches are designed to open on cooling at a different temp to closing and switching ON, to stop the fan contantly cutting in and out, I've got a fancy laser pointer IR thermometer which just confirms the temps, but 10 secs (roughly) under a flame is enough to heat to about 100

 

Ah Davidwort, excellent as usual :salute: I will attempt this tomorrow although i think that either way i'd have to invest in a new rad fan switch or new coolant :lol: I hope your guide will be simpler than it sounds once i get down to it - i'll let you know how i get on.

[jpowell79 0]

 

Another thing, I've just realised that VW will probably take ages to get the part in and don't take orders over the phone which is quite sh;t as i work in central London and i really need the car to work by the weekend. I've been on vwspares.co.uk

 

http://www.vwspares.co.uk/corrado_cooling.php

 

 

Just ordered one of these myself to swap out. cheers for the link :)

[n3p 3]

you can test the radiator fan switch, but you need to take it off the car, which unfortunately means raining your coolant really.

bit crude, but this is what I did:

if you have it off the car, the three pins consist of a common earth (can't remember which pin but look at the wiring to the connector block for that (brown))

 

and then the two speed circuits

 

if you connect a test light or multimeter up in continuity or resistance test position, neither path (earth to speed 1 or earth and speed 2) should be closed, i.e. a circuit through when it's at cold/room/air temp

 

heat over a candle or gently over a low gas hob, and you'll hear the circuits click shut, don't go too mad heating them as you only need to get to about 95 and 105 degrees.

 

repeat for each of the circuit paths (speed one and speed 2)

 

first speed should audibly click when it goes ON when heated and the circuit makes, speed 2 will follow a few seconds later as it's a few degrees higher

they should close one at a time as you let it cool down off the flame, multimeter just proves the circuit completes.

 

obviously heat gently as you don't want to melt the thing, and hold it in some mole grips rather than burning your fingers :)

 

the switches are designed to open on cooling at a different temp to closing and switching ON, to stop the fan contantly cutting in and out, I've got a fancy laser pointer IR thermometer which just confirms the temps, but 10 secs (roughly) under a flame is enough to heat to about 100

 

Ah Davidwort, excellent as usual :salute: I will attempt this tomorrow although i think that either way i'd have to invest in a new rad fan switch or new coolant :lol: I hope your guide will be simpler than it sounds once i get down to it - i'll let you know how i get on.

 

Thanks a lot david - after a bit of initial confusion i tested it and it turned out to be fine! I now have a spare brand new switch which strangely comes with a paper-ish gasket as Jim mentioned whereas the original one was copper :confused4: . Decided to change the thermostat which was a right PITA to get that sodding PAS pump out of the way, and that didn't fix the problem either. Thought about it for a minute, ran the car to temperature and literally just touched the electrical wire....whiiirrr....the fan switched on :bad-words: Why oh why didn't i do that to start with? I guess i can think positively and know that it has a new thermostat, but still. The wire in question goes into some fuse, and it's now taped up to the side of the radiator temporarily - think of it as a TV antenna, its positioned in a place where it works :lol: but i'm going to have to think of the best solution to fix the problem.

 

And the pressure problem in the top hose seems to have fixed itself....damn corrados

 

Just ordered one of these myself to swap out. cheers for the link :)

 

No probs, hope yours is cooling as it should now :salute:

[jpowell79 0]

got the switch.....but can't get the bugger off!

 

Do I need a specialist tool to unscrew it?

 

Nothing it my spanner set gets close!

[n3p 3]

On the 16v I removed the battery to get easier access and used mole grips to get the bugger off, it was actually a bit of a mission as it was completely crudded on. No sockets I had were big enough and I couldn't find the adjustable spanner :lol: Good luck :salute:

[davidwort 0]

The wire in question goes into some fuse, and it's now taped up to the side of the radiator

:scratch: got any pics?

glad you tracked it down though, if only my weekend was as productive, my golf has been going mental and a complete new throttle body (drive by wire compterised nonsense) made no difference, trying a new manifold pressure sensor tomorrow, the Corrado is so straightforward in comparison :mad2:

I now have a stinking cold and to top it all today the LNB on my satellite dish decided to stop receiving 50% of the channels including the HD ones :censored:

[n3p 3]

The wire in question goes into some fuse, and it's now taped up to the side of the radiator

:scratch: got any pics?

glad you tracked it down though, if only my weekend was as productive, my golf has been going mental and a complete new throttle body (drive by wire compterised nonsense) made no difference, trying a new manifold pressure sensor tomorrow, the Corrado is so straightforward in comparison :mad2:

I now have a stinking cold and to top it all today the LNB on my satellite dish decided to stop receiving 50% of the channels including the HD ones :censored:

 

I'll get some pics for you tomorrow - tbh i think the fuse thing could be from the uprated wiring loom i fitted, but if it actually was then i have no idea why or how it would affect the fan. The wiring is all pretty messed up anyway, not sure where i'd start in order to start tidying them up! I take it you have a mk4? We have one too, mechanically it hasn't let me down but the floors are completely soaked and I have mouldy door rubber...such a ballache i haven't even bothered to start repairing it yet! Good luck with it all though :salute:

[jpowell79 0]

 

Another thing, I've just realised that VW will probably take ages to get the part in and don't take orders over the phone which is quite sh;t as i work in central London and i really need the car to work by the weekend. I've been on vwspares.co.uk

 

http://www.vwspares.co.uk/corrado_cooling.php

 

 

Just ordered one of these myself to swap out. cheers for the link :)

 

 

Got my old one off eventually - had to by a 30mm socket from halfords to get it off - but that one I've just ordered from vwspares doesn't seem to fit snugly with the radiator switch plug. The old one fits snug and true (even though it's buggered!) but this new one doesn't want to fit.

 

Have I got the wrong part? I know I have a VR6, but surely it should be the same part? - I bought the second one....

 

http://www.vwspares.co.uk/product_info.php?products_id=407

 

but as I say it don't fit properly????

 

Anyone else had this issue?

[n3p 3]

Probably worth posting a new thread as VR6 owners may not visit this one. Does it leak with the new one in place? Did you get a gasket with your order? :nuts:

[jpowell79 0]

Picking up the new rad switch from the Volkswagen dealers tonight so will let you know.

 

 

slightly off topic.... but whenever I go there I keep being enticed by the new Scirroco R!!!

 

Wish I had the wonga to get one! :D