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I recently replaced my primary engine cooling fan with an electric fan. In this post, I'll cover the eFan I chose, modifications to it that allowed me to use it in the original fan shroud and report on how effective a replacement it has been in my testing.
I shopped around for an eFan for a long time and had many in my baskets at various vendors trying to decide which one suited all my requirements.
Initially, I was trying to stop a tendency to overheat that had left me waiting for my Jag to cool before I could limp her home. That turned out to be a bad fan clutch. Replacement brought cooling back under control. When that clutch began failing after 6 months I decided to find an eFan rather than replace the clutch again.
I looked for flat units most have a strong taper to their housing, or the guard. I also wanted one that had a high CFM rating intended as a primary radiator fan, not an auxiliary.
Clearly those mounting feet won't fit, but that's ok. they make nice stout attachment points once I trimmed them with a hacksaw.
Cut them in half vertically. I need room in front of them for a seal.
Cut them to height to fit inside the shroud snuggly.
Press it into the shroud.
Nice and snug in there.
After confirming the shroud would go back in place with the eFan attached, which required a little adjustment. I basically made the fan parallel to the radiator which the shroud opening is not. This put the lower edge of the fan's built-in shroud very close to the radiator. This is fine, but reduces the area of the radiator that the fan will draw through. I modified the built-in shroud to allow it to draw through the whole shrouded area. Zigzag area is to the corner of the rad. Areas removed entirely are to the top, center of the rad. I could have trimmed the whole built-in shroud short, but this plastic a a beast! Remarkably hard, and as you can see here my cuts wanted to wander. In the end I feel I should have used a reciprocating saw instead, but this is all hidden radiator-side so I called it "done"!
modified built-in fan shroud.
To create a seal between the fan and the OEM shroud I used foam rubber pipe insulation. This has an adhesive on the cut edges to rejoin it around a pipe.
I cut an 8 foot stick of it in half lengthwise so I had one adhesive edge on a rainbow shaped piece. This was adhered to the leading edge of the fan. When pressed into the OEM shroud from the rear it made a lovely seal.
In the engine bay there's so much more room!
There's about an inch clearance there between the main pulley and the fan.
Not pictured here, I marked up the shroud where the fan feet contacted it and pre-drilled holes for four stainless steel screws. These go into the remaining stubs of the mounting feet.
Another concern I had doing this was that I wanted to keep the bay looking good. And I feel like it has a legitimate look. Not obviously un-original to those who don't know what should be there.
Polished looking install IMHO.
So, how does it do?
Noise:
Noise from the OEM mechanic fan was pretty bad. From the front of the car it overwhelmed the sound of the engine. Noise from this eFan is audible, but barely, from the front of the car. Inside, the fuel pump is louder than this fan is!
Cooling capacity:
On low setting this fan keeps the tStats busy. The temperature does not fluctuate from the tStats temp rating at all. Hard highway driving in >90F temps, pull off a ramp and sit at a stop light, idle there a few minutes, race off to sit in traffic, whatever. It does not vary. I will be replacing my 88C tStats with standard temp units since I no longer reach Normal temp. Sits just below the "N". For those who are going to ask, I have a real temp sender not the steady-reading BS one. And my gauge goes up to and above the "N" when parked and turned off after a run. Drops back to just below in less than a minute when cranked.
UPDATE: This Friday and Saturday were exceptionally hot even for us in the Southern US. Over 100F ( 38C ) on my porch in the shade. I got a little worried that something had gone wrong. Temps rose above normal spot, right up into the "N"! Then to the top of the "N"! But that's where they stopped, and even with the Derale on HIGH and with the AUX fan kicking, it stayed right there at the top of the "N". I take that to mean that's all the rad could drop the coolant temp given the ambient temps.
I trigger this fan with a Spall Fan controller. It's a really nice high-amp relay that's epoxy sealed on the bottom for a clean water-proof install and a single-wire 85º temp sender with and adapter sleeve that is not correct thread to replace the OEM Jag unit. More info on this unit available if it's desired.
My car's running hot this summer, so I'm starting to wonder if an electric fan might not be an idea. Lots of good photos and information in this post. I need to do more reading and research before I make the change, however, but the improved cooling while waiting at the lights is something I would really like.
looks good but looks a lot of work, I couldn't be bothered with all that and so I got a coolercats set up from Dallas, It was fitted in an hour and works so well aircon even improved.
another good thing about this mod is that I changed my front crankshaft oilseal in under an hour as there is ample room without any front end dismantling,
My car's running hot this summer, so I'm starting to wonder if an electric fan might not be an idea. Lots of good photos and information in this post. I need to do more reading and research before I make the change, however, but the improved cooling while waiting at the lights is something I would really like.
You have an ally rad, I seem to remember. The OEM engine driven fan setup is extremely good when working as designed. What, exactly, does "running hot" mean in your case Someday? If your car really is so doing, then a new fan clutch, or checking the fan belt tightness, are the likely contenders.
I have electric fans, which I fitted for non-cooling related reasons. They need careful fitting, you need to buy very high quality ones for them to be reliable, and controlling them is not that straightforward.
Greg
You have an ally rad, I seem to remember. The OEM engine driven fan setup is extremely good when working as designed. What, exactly, does "running hot" mean in your case Someday? If your car really is so doing, then a new fan clutch, or checking the fan belt tightness, are the likely contenders.
I have electric fans, which I fitted for non-cooling related reasons. They need careful fitting, you need to buy very high quality ones for them to be reliable, and controlling them is not that straightforward.
Greg
Hi Greg. That's right. Last year I got a new ally rad, new thermostats, new hoses, and a new fan. Normally she runs at most a needle-width to the right of the middle mark, but now it's summer, in traffic (at the lights), on a few occasions now she's crept up past that. After the first time, I checked the coolant, found it so low I could barely see any, and topped it up with 50/50 premix. That seemed to help (though a cooler spell also helped), but the other day she was up there again - both times it's been fairly up there it's been near the end of the run. Checking the coolant again, I once more found almost none visible. But there aren't any apparent leaks - laid down cardboard overnight underneath to check. Could it be evaporating out from somewhere? The caps, for example? The main cap was replaced with one from a Mercedes Benz, but it fits perfectly. Incidentally, when I removed the cap to check, the bottom of the cap was wet with coolant. So there does appear to be plenty in the system.
I grabbed some pics (low quality, as I used my tablet camera). The first photo is waiting at the lights the first time I noticed this. I was using the a/c this time.
The second time, I wasn't even using the a/c when I noticed her creeping up in the last five or ten minutes of my drive, going through downtown. I let her idle in the carpark to see just how high she would go. She seemed to stop at about this point:
That's about a needle-width gap between the needle and the outer white marker (I check the gauge with one eye, from straight on, as the distance between the needle and the gauge face can make it look worse).
As this happens when idling, and she drops down to normal levels with better airflow/higher revs, I experimented by putting her in neutral and revving her to 1500-2000 rpm. That did drop the temp, but only to about halfway between the markers (she might have dropped more if I revved her for longer, mind). Interestingly, now that it's summer, once she's warmed up she idles lower than winter - down to 600 rpm at times. In winter it's more like 800 rpm.
Spinning the fan by hand when she's warm, the fan only moves a couple of blades' worth around. However, the fan only moves that amount when the engine's cold as well. So I'm not sure what this says about the clutch. All belts were checked just a few months ago (albeit before my 2,700 km road trip). The heat sensor stickers I applied a few months ago still show maximum temperatures of over 99 but under 104 degrees - there's no change in any of them. So I don't think she's overheating as badly as the gauge would suggest.
Sorry for the length of this. I just wanted to give you all the information I can think of. I do want to keep the OEM setup if possible. Incidentally, the aux fan comes on and goes off perfectly normally. The climate out here these days is daytime highs up to 35C or 95F, and humidity levels in the 70s and 80s. It's a very wet heat (especially today when the typhoon passed over us...), so I wonder if that might affect the radiator's ability to vent heat into the air.
Any suggestions or advice would of course be gratefully received, as always....
No cooling issues, just a fan blade poking out the bonnet.
Sadly these fans are NLA from Ford/Bosch, and the China ones are crap.
The RH fan is thermo switched by the standard Jag switch in the water inlet of the pump, and teh LH is A/C switched only.
Best test was in 45C and traffic at a standstill, just "kissed" the N, and I was in that rubbish for nearly an hour. Glad I had the big alternator working just right.
Agree on the room available, and even MORE when you slice the front V from the pulley pack.
Someday
Where are you looking to see low coolant? In the central filler spout or in the wing tank? How much are you adding at a time? FWIW, I would use the correct filler cap as supplied for the car by a reputable supplier/maker.
I do not think your car should get quite that high on the gauge, so I suspect something is not quite right; but an electric fan will not sort it. Get the system 100% as is, before doing any other mods, is my view.
A new fan clutch cannot hurt, they are not the most long-lived of items and a sensible bit of preventative maintenance, IMO. In your place I would do that anyway, and change the two filler caps, go round each hose and ensure the clips are tight, particularly the hose between the water pump inlet and the bottom of the rad where it joins the pump. This is hard to see, let alone get at, but frequently needs a tighten. Also carefully measure the coolant you are adding, and report back. Your engine is not in danger at those temps, but it needs correcting.
Greg
Last edited by Greg in France; 08-08-2017 at 04:42 AM.
Running at that Temperature would make me Paranoid, my Grey XJS almost never needs topping up at all and my red one before it went TU
Only needed 1/2 pint before every trip, as I did have a little bit of a leak that I was gradually nailing down which was due to a couple of faulty hose clips.
Maybe its the header Tank you should be looking at.
Hi Greg - I'm checking and adding coolant from the central cap, not the one by the wing (though I have checked that too, out of curiosity - I used to be able to see coolant easily in it, and can't now).
Last time I added nearly a litre of coolant - perhaps 850 mls before I could see the coolant in the central spout at an acceptable level (I didn't want to overfill - a couple of weeks back when I checked, the coolant started spurting out as soon as I got the cap halfway open (and yes, the engine was very cold)).
I'll take a look tomorrow for loose hoses, to the extent I can. She's going in soon to get the rear shocks replaced and the diff oil leak fixed, so I'll ask them to have a look at the coolant issue as well. And I think I might look for some new Jaguar caps and a new fan clutch too. She's only done 56,000 km (35,000 miles), but if it's an age thing rather than a wear thing, it's probably well past due....
OB - The header tank (the one behind the wheel, you mean?). Yes, that temp does make me a bit paranoid. Luckily it's still the exception rather than the norm, and the thermal labels on the engine water pipes suggest things aren't as scary as they look, but I do worry. I generally check the temp automatically every time I'm stopped at the lights....
The water bottle in the front left corner of the engine bay (with a cap) can fail, but more so a hose will be failing or is perished. So I'd be looking at the hoses. Can also be a leaky rubber seal around the thermostat housings to the water rails... Or a leaky heat exchanger... Or a leaky heating valve... Or... (you get the point). There are so many rubber hoses, it can leak from everywhere. Maybe even the water pump... Simply park your car one day, SDSD, and leave it standing on some cardboard. If you can...
You should then see any traces of water/coolant on the cardboard... Check above that area then for water drops until you find the culprit. In my XJ8 it was the darn stoooooopid Octopus Hose. Again a quality piece of British rubber... I'm replacing every single little piece of rubber in my engine bay. I want a water, oil and fuel tight engine. And I will have exactly that!
Hi Daim. Thanks for chiming in. I tried the cardboard trick. The other night I left her with cardboard under the engine, two sheets to cover as much as possible, and nothing showed up. So if it is a leak, it's either pooling in something, or is a very slow one indeed. There was a leak last year from the hose that connects to the bottom right of the rad, and the entire hose was replaced at considerable expense with a rather upgraded one, but when she was hoisted up a couple of weeks ago we looked at that (just as the car was up) and that leak site was fine. Apart from a spot of oil, the engine area seemed leak-free. (I'm not too worried about a minor oil leak. It wouldn't be a British car if it didn't leak oil. A non-leaking British car almost seems like cheating....)
Just to make sure, I might try the cardboard thing again, however.
The water bottle you refer to is the black metal one with the second cap, right? That was replaced last year.
Someday
If you are adding that amount of coolant regularly, you have a leak and that is your problem, for sure.
New pressure caps for spout and wing tank are a priority. Part numbers CCC6707 (2 off) assuming you have a 6 litre car. These may well be all that is wrong. DStant is a good brand, but any from a good supplier (eg D Manners) will do. 16 or 18 psi caps, NOT less. Radiator Cap-Safety Release STANT 10330 | eBay
or http://www.jagspares.co.uk/Manners/p...partno=CCC6707
Full check of all hose clips also. They all need to be checked, including the ones to the heater.
To top up coolant do as follows: Remove BOTH caps (central spout and inner wing ones). Fill with coolant mix the CENTRE spout until wing tank full to overflowing. Replace wing tank cap. Fill centre spout to overflowing. Replace centre cap.
Check tightness of thermostat casting nuts too, and look for drips round their mating faces. Garages often replace gaskets poorly, or put them the wrong side of the thermostat!
Finally, the hose from the inner wing expansion tank to the atmospheric tank can get blocked. Undo the hose (3 in the diagram below) and blow through it. You should hear water bubbling in the tank hidden inside the wing cavity behind the wheel arch cover. If you cannot blow through the hose it is blocked and must be unblocked.
Greg
Last edited by Greg in France; 08-08-2017 at 06:31 AM.
I recently replaced my primary engine cooling fan with an electric fan. In this post, I'll cover the eFan I chose, modifications to it that allowed me to use it in the original fan shroud and report on how effective a replacement it has been in my testing.
So far, no power issues running this fan and lights and wipers together, but it's definately a lot of draw. I have the 75A alternator.
I have the 115A alternator from later models on hand. New pulley and fan for it as the current alt has the smaller shaft. I plan to put the new alt in place of the air pump. Air pump bracket to be modified by a local welding shop. The bolt is the proper 10mm used by the new alt, but the mounting is a bit too narrow for the alt to fit.
I would suggest that that any additional power draw on these 75A Jags be accompanied by an alternator upgrade.
08-07-2017, 12:02 PM
Primary Cooling fan: eFan Upgrade
I'm replacing every single little piece of rubber in my engine bay. I want a water, oil and fuel tight engine. And I will have exactly that! 
