Radiator fans - advice please?

[steve_earwig]

*sees mjb's post* Oh bugger. Ah well...

Oh, I gotcha now. Sounds like the brushes are worn out and not passing enough current to start them spinning. Are they pretty slow after that?

Or are they really stiff??

The only other things I can think of is the connections on the fans themselves (which you won't know 'til you get one off) or maybe they're not getting the full 12 volts (got a meter?)

I wasn't 100% serious about the Kenlowe fan, it's just the Pug ones are so rediculously expensive. It looks like a 13" will do the trick but there doesn't appear to be a way of comparing the performance of a Kenlowe to the originals without actually trying it. I've just had a trawl on their website and it looks promising but I just can't say.

The thing with the Kenlowe is you'll probably have to modify the fan carrier, then I suppose you either use one existing feed to one and live with it pulsing (I think it was mjb said he never worried about it) or work out a way to run it at half speed when the originals should be running in series, maybe configuring the existing relays so that one feeds it straight and the other through a big heat sinked power resistor. Obviously you'd have to work all this out before you part with any cash in case the difference in cost between this and the originals isn't worth all the ag.

[johnfoss]

Once again, thanks Steve and MJB.

Steve, yes the fans run slow, in particular the left hand one, which is also the one that 'wobbles' the most. Don't think I'm going to go down the Kenlowe route, but thanks for looking mate.

Looks like my weekend, will be trawling around the scrappies, around the Heathrow area

Don't suppose anyone on here is breaking a 406

John

[mjb]

Oh, I gotcha now. Sounds like the brushes are worn out and not passing enough current to start them spinning.

Brushes are worn, oily, or there's a muck buildup perhaps?

The only other things I can think of is the connections on the fans themselves (which you won't know 'til you get one off) or maybe they're not getting the full 12 volts (got a meter?)

12v is for 'full speed', they should run at 6v for 'slow'. Basically full speed is both fans running in parallel whereas the slow speed is them working in serial. If one fan doesn't work then neither will run slow - which was my problem.

I suppose you either use one existing feed to one and live with it pulsing (I think it was mjb said he never worried about it)

I wouldn't, not if both are dodgy. My one working fan was fine, but it must be stressed that petrol engines can get the coolant very hot very quickly if there's no air movement - a hot engine running stationary in hot weather will switch the fan on and off every minute or so - that's how fast the coolant level goes from about 85ish to over 100. Get stuck in traffic without a working fan and you're in serious trouble.

I'd go for the replacement pair of fans - the last thing you want it to be constantly worrying about whether or not you're going to make it to your destination...

[steve_earwig]

Sorry M, I meant one Kenlowe fan, apparently the 13" will cool a 3 to 4.5 litre lump.

If the fans were really stiff I'd have thought maybe bearings but that does sound like the brushes. I had to replace them on one of mine but the other was full of crud as you say, mostly rust and brush dust, which I blew out and it's still working (touch wood). The air con on these cars seem to have a mind of its own and it's impossible to turn off permanently, the fans are cooling the condensor all the time it's running so the brushes will wear down rather quick.

I think if I picked up a Kenlowe cheap I'd give it a go, if only to shove the old ones in the bin and give Pug the finger.

John, if you do get some fans out the breakers, make sure they write on them so you can take 'em back if they're duff!

[teamster1975]

Great posts Gents, I'll be following your advice when I get some free time at the weekend.
Thankyou very much!

[mjb]

The air con on these cars seem to have a mind of its own and it's impossible to turn off permanently,

I'm sure it's possible somehow. Perhaps there's an overpressure cut-off that could be rigged, or (and I'm not overly familiar with refrigeration systems) if the compressor is the only 'active' component, surely pulling the plug to the clutch solenoid would do the job?

Or you could just employ a post-it note to remind you to turn it to eco each time you get in?

[johnfoss]

Well guys.

Tomorrow's gonna be a fun day After trawling the scrap yards today, I've located a twin set of fans from a low mileage D8, complete with cowling, relays and wiring loom, the guy in charge, even took them off for me, showing me every step and tools required.

Total price? -----------

£40

and with a 7day, no quibble, full refund, if any problems.......... already put 12v across them and they fire up like hell .

Let you know how it goes.

John

[mjb]

£40? Well done!

[steve_earwig]

Fantastic! I'd be interested to know how it goes, is there a trick to getting the air con condenser out of the way?

Mjb: the easiest way is to disconnect the compressor!

[teamster1975]

£40? Well done!

Too right!
The left hand fan is farked on mine and it's losing coolant again, I'll have to get down the scrappy AGAIN

[johnfoss]

Hiya guys.

I now have two working fans on my D8, engine temperature is spot on and the a/c is ice cold again . I'll summarise what was done below. But to start with I had the complete cowling with both fans mounted, obtained from my scrap yard -

1. Remove slatted grill from between headlights.
2. Remove both head-lights (3 bolts and a spring clip on each).
3. Remove front bumper and inner absorbtion thingy.

This gives you superb access to the radiators and fans.

4. Remove motors, complete with fan blades from new cowling (3x10mm bolts)
5. Remove upper cross member (with bonnet catches - 2x10mm and 4x13mm bolts) and place to one side.
6. Unclip spring clips on either side of radiator.

You'll now find that you can push the inner 2 radiators back towards the engine block, giving you access to the radiator, immediately behind the fans, look up in the top corners and you will find 2xT4 hex screws, remove these and this radiator will push back enough for you to get behind the fan motors and using a small 10mm socket, -

7. Undo the 3x10mm bolts holding the old fan motors on, and replace with new motors.
8. Once both are on, ignition on and pull the temperature sensor switch off and hey presto a quick check and the fans are working.....

Put it all back together in the reverse of above.

No need to remove any condensor pipes, radiator hoses etc

Total time taken, with no Haynes manual and on my own, 2hrs.

If anyone wants more details, feel free to pm me.

John

Big thanks to Steve and MJB for all their advice.

[steve_earwig]

2 hours! That's amazing!!

[mjb]

Nice one. How do you take the bumper off? I've been under and around it so many times but can't recall ever noticing where it's attached

[johnfoss]

MJB.

Front bumper removal -

1. Remove slatted grill from between head lights.
2. Remove 2 x torx screws from each inner wheel lining (just above bumper and top of arch - caked in dirt, but there!).
3. On each corner, under bumper, 3 x torx screws, holding under tray on, remove these.
4. Centre of bumper, underneath 8mm bolt holding under tray on, remove this.
5. Pull back inner wheel liner and on the edge of the bumper, you will find 1 x 10mm bolt, using a 3/4" ratchet and extension bar, remove from both sides.
6. Top centre of bumper (in front of fans) 2 x 8mm bolts, remove these.

Bumper will slide off and down, if you have fog lamps, unclip both plugs. Job done

Behind the plastic bumper, you will find an absorption thingy, black in colour, this is held on by 2 x 13mm bolts, one on each end.

John

[mjb]

Thanks