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MG MGF Technical - Fan fuse(s)

I know there is a recomendation to change the front fan fuse to a 20 amp one, should the engine bay fan also be changed to a 20 amp one?
Kevin s

No, no need to upgrade the engine bay fan - unlike the rad fan, the engine bay fan usually gets a frequent work out (although, curiously, less so on the VVC)
Rob Bell

I have never had my engine bay fan come on (VVC) but the rad fan always seems to be on ! I take I just need to change fuse 6 in the engine bay?
Kevin s

Kevin, I can never tell when the rad fan is on on my car - it's inaudible from the cockpit - are you sure that your's is always on?

If it is always coming on, then there probably isn't any need to replace the fuse: the 20A fuse only prevents unnecessary fuse replacement as the current draw on a fan that hasn't been used for a long period of time can exceed the 15A rating of the original... if the fan is used all the time, the 15A fuse is perfectly adequate.
Rob Bell

Rob,

I can definately hear when my fan is on, thats why I checked the water etc after a run and heard it running - I thought there was a problem but I understand it is normal for it to run after a "spirited" drive!!! I have never had the engine fan on, is there a way to check it works similar to pulling the lead off the sensor for the front fan?
Kevin s

The engine bay fan is the one that is usually audible Kevin - are you sure that you are hearing the rad fan - because if you are, then there is a problem with it...
Rob Bell

Yes, it is the rad fan, if I walk to the front of the car You can definately hear it. You can look at the engine fan and see it is not moving.

Why do you say I have a problem??
Kevin s

When the rad fan on my car comes on I can hear it if I stand in front of the car but not from inside. When the engine bay fan comes on I can hear it from inside when I open the door (could probably hear it at a standstill with the window open I didn't have an SP exhaust!). The engine bay fan's very obvious when it stays on after you switch off and leave the car. Not sure if the rad fan stays on after switch off or not - mine very rarely comes on at all.

Tim.
Tim Jenner

Forgot to say, you don't need to look at the engine bay fan to see if it's on - it's very obvious when it is!

Tim.
Tim Jenner

>Why do you say I have a problem??

The fan comes on only occasionally, even after a hard thrash (high speeds as well as high loads) the rad and return pipes will be quite cold, the car should take a least a minute or two just sitting to heat up the rad to the point where the fan needs to come on.

If the fan is comming on 'early' then you have one of three problems:
1) Dirty/faulty/unplugged temp sensor causing the ECU to be nervous at lower temps
2) Air in the rad, (make sure expansion tank is at the upper marker and open, then open plastic nut on rad till coolant exscapes)
3) Stuck thermostat, but I would expect the needle to move with this problem.
Will Munns

PS. Don't check the coolant level unless the engine is cold, else you risk making air pockets in the engine/rad.
Will Munns

I do know that my rad needs replacing - 60% ish of the vanes between the cooling tubes are missing, My car temp rises if sustained speeds of 90 are kept up for more than 15mins - temp rises steadily until I slow and then the temp goes down. The fan is definately on then (rad NOT engine) how do I check the engine bay fan?
Kevin s

That would do it!

If the temp gauge moves _AT ALL_ you have a problem - get the rad fixed

Will
Will Munns

Kevin,

Cost of Rad now?

versus

Cost of Rad + HGF + whatever other damage?

As Will says - get it fiexed!
Dave Livingstone

fiexed - I thought Will was the dsylexic?
Dave Livingstone

Guilty, I may well have said "fiexed!", but just spelt it wrong when I typed it in ;-)
Will Munns

Yes you are all correct, my K&N and 53mm TB will have to wait - I will fit a TF rad I think might as well do the underbody pipes as well?!?!?!
Kevin s

Wise decision Kevin :-)
Dave Livingstone

Yes, absolutely Kevin! :o)
Rob Bell

HMMM, just read that again - 53mm TB? a new size perhaps? no just pudgy paws.....
Kevin s

This thread was discussed between 04/10/2004 and 05/10/2004

MG MGF Technical index

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