16v cooling fan always on

[SimonJ]

Hi there i've just bought a j plate 16v with 158k on the clock, i love the car but the other day i noticed that the cooling fan comes on when you turn on the ignition, and runs constantly. The car has had a head rebuild 6 months ago with new head gasket etc. I think someone has wired it prior to this to prevent overheating.
I want to change it back because it takes ages to warm up with the fan on. Another thing is that if you spin the fan with ignition off, the blades hit the black cowling on the radiator, surely that is wrong! did the 16v have a bigger radiator than other golfs? I compared it to my 8v which i haven't sold yet and the rad was the same size but the blades on the fan spin freely. I'm thinking the wrong radiator was fitted, or could it be thermo switch or thermostat? Any help appreciated
p.s. im doing an oil change soon so any recommendations? on my 8v i always used vw quantum silver. Cheers

[monzablue16v]

Hi mate
Welcome to the forum

I'd check the thermo switch on the bottom of the radiator first and go from there usually stops working altogether when they go so someone may well have wired it to an ignition feed as a temporary fix. I can check wire colours etc if you want.

The fan should spin freely in the cowling and not catch size wise not sure of any difference in them but I'll take a photo of mine if you want to compare.

As for the oil the general view on here is use a VAG oil filter as these have non return valves to stop oil flowing back from your tappets and Synta Silver oil from a VW dealer and don't forget your copper washer for the sump plug. did mine a couple of thousand ago and still got clean oil looks like it did when it went in!

[monzablue16v]

Here you go this is a 16v one if it's different it's cheap so problem solved just gotta work out why it always runs

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=9889&item=4562198684&rd=1

[SimonJ]

hi there mate thanks for the advice i was pretty sure on the oil it is good stuff. My local VW dealer heritage volkswagen in bristol used do do an offer £7.99 inc VAT for 5L of silver synta  and oil filter was £3.84 inc VAT, should have stocked up cos it's about £15 now!
I'll try and get some pictures on of the wiring because there is some that looks like it has been fiddled with, i.e. new connectors. There is a red and brown presume live and neutral coming from some wires in a cluster which trace back down by headlamp back towards the bulkhead. These wires connect to red and brown in the fan wiring down to thermoswitch but there are some other wires red/white as well which go to the fan connector.
I disconnected the red and brown earlier and turned the ignition on and the fan never came on, but i ran the engine for ages, and it didn't kick in at all, engine oil temp was 112 c and coolant started to boil in expansion tank, and was escaping.The temp gauge was above half way. I'll try the thermo switch and put picture on to show u if i can 2mor.
Cheers for your help with this mate

[Judderi]

Deffo sounds like the thermostat has gone and somebody has just hard wired it to the ignition rather than buying a new thermostat.

[rubjonny]

The proper 16v radiator is actually smaller than the 8v one because it's dual core, it's the same width as the one fitted to the 1.6 Driver & the 1.6 rad fan shroud is a straight swap.

The wiring for the rad is pretty straight forward, you should have a live & earth wire going to the radiator switch, then 1 from the rad switch to the fan (2 wires if you have a dual speed fan) and an extra earth connection to the fan.

[SimonJ]

Sorted the problem by comparing the wiring to my 8v and found there was an extra black wire connected on the 16v, I simply disconnected it, and the fan now works fine, the thermo switch and thermostat work fine, so it must have been done to disguise the car running hot before headgasket. 

[monzablue16v]

Good work fella!!! good to know you fixed it.