Anyway, just as it was on its way back from the garage after passing it's MOT, the radiator fan packed up!
After trawling the internet trying to find the right part, I managed to source a new fan.
Fitted it, and hey presto! Working fan.
Only one problem, once it comes on, it doesn't turn off.
I thought it might be the fan switch so I changed it for a new one but it made no difference.
Today I've done some testing to see exactly what's happening.
I plugged in the tech1 so I could constantly measure the coolant temperature and ran the engine until the fan kicked in.
It came on at 108 degrees, after a few minuets it had cooled down all the way to 89 degrees and there it sat at a constant temperature, fan at full blast for a good 10 minuets until I turned the engine off.
I thought I'd do a control experiment so I did the same thing on the CD auto (this is a no cat 20NE but it's mostly the same engine).
It must be said that this engine took allot longer to get hot. It got up to around 90 degrees quickly but it took some encouragement to get much hotter.
Eventually the fan turned on at 109 degrees, stayed on for about one minuet and turned off once the engine was down to 100 degrees.
The CD manual has always been a pretty hot running engine. It always got up to temperature faster than my other two (C)20NE equipped Cavs and the fan came on allot more.
I did try and eliminate the problem a few years ago by completely replacing the coolant system; I changed both temperature sensors, fitted a new radiator, fitted a new thermostat, had the water pump replaced, fitted a new fan switch and replaced the coolant and flushed the system several times.
None of this made any difference.
In the end I give up trying to solve the issue and just accepted that this is a hot running engine.
I've thought that it could be a few things, like a lean air/fuel ratio or a blown head gasket.
However I've done a sniffer test and it indicates that the head gasket is fine.
Not 100% about the air/fuel ratio but there is nothing odd about the smell of exhaust gasses or anything coming up as odd on the tech1.
Does anyone have any ideas?
