Intermittent fan issues

[skinnyman9000 0]

Recently my car has been getting stupidly hot, like over 110 water temps. I had a good gander around the engine bay yesterday afternoon and everything seemed fine, so i took it for a run. Gave it a pretty hard time and couldnt get the water over 95 or the oil over 110, the fan was kicking in and out when it should have been.

 

However, i went for a drive last night and got silly temperatures again, i pulled over to discover the fan wasnt turning on at all, so the water in the radiator was just getting hotter and hotter. I replaced the fan (with a working 2nd hand unit) a few months ago, and the fan switch was replaced last year. Now to me it sounds like one of these things has gone again. The MFA seems to be displaying the correct temps, but then the fan just isnt working.

 

Are there any tests i can do to determine what part of the system is failing? I dont fancy spending yet more money on a new fan if it turns out to be a knackered sensor somewhere.

 

This car is testing my patience now, if this turns out to be expensive it may spell the end for it.

[skinnyman9000 0]

Anyone?

[vw domo 0]

iv just replaced my fan switch with one of the cheep ones off ebay, think it was like a tenner.

 

i get water temps of around 75deg (no higher than 85) and oil temps of around 110 now :D

 

my water temps used to always be around 90-100 deg (which i thought was normal) till the fan switch went and my fan was stuck on full.

might be worth changing for a tenner......

[skinnyman9000 0]

How easy is this and where abouts is the fan switch? I've no idea as the local garage replaced it last time

[skinnyman9000 0]

Ive tried the paper clip across the temp sendor trick and the fan comes on, so im thinking it must be the fan switch? The fan doesnt come on at all sometimes, so im guessing that there is a fault inthe switch, bit bad as it was replaced last year!

 

My plan though is to wait until the fan doesnt kick in and everything gets hot again, and then try the trick above. I guess if the fan turns on then it must be the switch?

[davidwort 0]

there's a relay on top of the fusebox that controls the fan operation on the early cars, it's possible that isn't operating correctly(sticking?) , so don't assume it's just the switch, sorry but I've never had to trace this myself (yet!) so I don't have any more info.

[skinnyman9000 0]

Hmmmm.

 

Well question, if this is sticking (and therefore the fan doesnt turn on) will the fan then turn on when i bridge the temp sensor pins?

 

i need a test that will pinpoint the issue, something that will tell me exactly what it is. I know this is a big ask of a corrado :lol:

[vw domo 0]

If davidwort is right and it is the relay then you should be able to tell from a bridge.

 

It sounds similar to the kind of temps i had for years befor the fan switch went all together, so i got one of these http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=170480800561&ssPageName=STRK:MEWNX:IT did the job :D

 

It was located in the botom right corner of the red as you look at it, i asume its the same on the early models. good luck with it.

[skinnyman9000 0]

Ive been told that the relay controls the fan after engine shutdown, so shouldnt lead to an issue with the engine running as the switch link remains live? Not sure if this is true.

 

Well since saturday its been running fine, i need it to happen again so i cant test to see if its the switch, but sods law has meant its been running ok. As soon as it happens again (if it does) i'll bring the connections at the switch it see if its sticking. I guessing it must be as there are only a few components in the fan system and they all seem to be working.

 

Cheers for the help guys, i'll report back when i can