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The Heating and Cooling systems don't neatly fit into the other categories. The heat (and power for refrigeration) comes from the engine, but it's primarily about the interior comfort. Rather than agonise, it has it's own section here.

Contents 1 Description 2 Common Faults and Fixes 2.1 Refilling the coolant 2.2 Aircon blowing hot air 2.3 Blank Display on the heater control. 2.4 Changing Pollen Filters 3 Viscous Fan Problems 4 Fitting Kenlowe Fans 4.1 Removing old fan 4.2 Brackets 4.3 Thermostat 4.4 Wiring

[edit] Description

See also AirCon, Heater Matrix

[edit] Common Faults and Fixes

[edit] Refilling the coolant

From Elliot Mansfield o­n the Dakar4x4 list. This is aimed at the older engine incarnations, but the procedure is the same:

Remove the filler plug in rad, and the cap from the expansion tank (you do have o­ne right!).

Fill the rad right up to the top with water. Then start the engine and wait for the thermo to open. Usally the water level in the rad will drop down a few inches, top the water back up to the top, and allow the bubbles to come out.

As its starts to produce steam, quickly replace the filler plug. (otherwise it just boils over).

Top up the expansion tank to the line, but keep the lid off. Allow more bubbles out, untill it get close to boiling. Keep topping up the expansion tank as req. o­nce it starts to get quite hot, I replace the cap o­n the tank, and leave it to run, giving the top hose a few squezees to check that there water in it.

Then I stop it, leave it for a few mins, then take the filler cap of, and check the levels. I squeeze the top hose the make sure it's full of water. If it over heats whilst doing this, its usally best to let it cool down completely and start again - becuase all that happens is that the block just instantly boils the water, causing loads of steam to be blown ut, and actually sucking more air in.

The other tip from the workshop manual is to blow though the top return line to the overflow reservoir to make sure this isn't airlocked before starting.

[edit] Aircon blowing hot air

Aircon is blowing hot air? My dealer says I need a new compressor......

A fairly common fault is that after a short stop on a hot day, the aircon fails to, well, aircon, and blows hot air into the cabin. This may or may not be accompanied by the "book" symbol appearing on the display.

The problem is caused by the clutch in the compressor failing to engage. There are two causes to this problem. The first is that there is a higher than normal voltage drop over the wiring harness. There is a Land Rover Service Bulletin which describes this, and describes a replacement wiring harness part number YMQ104590AA, which has an additional resistor and relay (RL10). If RL10 is fitted in your fusebox, then you have the new harness. The new harness switches power direct from the alternator to the compressor clutch. If the voltage at the compressor clutch is less than 11.5 V thenn you will need this replacement harness fitted.

The lower voltage to the clutch can contribute to the second problem, which is wear of the compressor clutch itself. There should be a gap of 0.8mm around the front plate of the compressor clutch. If this is not the case, then the clutch needs adjusting. There is a Land Rover technical bulletin which describes how to remove the complete compressor and overhaul the clutch; however there is a simpler repair option open to the DIY mechanic.

Adam Moore sent the following information to the RRO mailing list:

I had the same problem with my '95 4.0 this spring. The A/C would intermittently not work, I traced it to the compressor clutch not engaging and had the same experience as you did, if I hit the clutch it would engage.

The dealer wanted to replace the whole compressor to the tune of $1,000, in my internet search for a better price on the compressor I found instructions on the Sanden UK web site to fix the problem.

Here is the abridged explanation, the whole operation is on the Sanden UK web site but sounds much more complicated and suggests the use of special tools; so here is the shade tree mechanic version:

1. With the serpentine belt in place, remove the nut on the end of the a/c clutch drive.

2. Use a flat head screwdriver to remove the outer clutch plate, be careful as this plate is actually a spring plate and if you over torque it you could make it worse.

3. Remove clutch and 1 of the spacer washers at the base of the shaft.

4. Reassemble the whole thing and enjoy trouble free a/c

The problem will be evident when you have it apart. There are rubber stoppers to ensure that the distance between the clutch and magnet is maintained. Over time these compress and the distance is allowed to increase, so that sometimes the clutch is just out of the magnets reach and can not engage. Removing the spacer brings the whole assembly back into specs.

---

You may find the original instructions in the Support Section of Sanden's website.

Section 14.1b details the removal of the clutch plate, and 14.6 details the reassembly procedure.

In addition to Adam Moore's instructions, when re-assembling the unit in step 4, the retaining nut should be torqued to the following specifications:

• 1/2-20: 20-25 ft•lb (27-34 N•m, 270-350 kg•cm)
• M8: 11-15 ft•lb (15-21 N•m, 150-210 kgf•cm)

I had very similar symptoms, aircon began to blow hot air after 8 -10 min of in town driving and Test Book appears. After compressor shim and relay check and voltage check on compressor feed, it was blocked radiator. Anyone with 100K or more should make sure to check flow. All is well now! PS. Test Book at dealer showed nothing because it was not an electrical issue. Ice cold now and no Test Book

[edit] Blank Display on the heater control.

Don't panic! The display is a reverse LCD with a light behind it, and the segments go clear to allow light through to make up the display. The good news is that the problem is almost certainly the light, which is about 60p to replace. The bad news is that if the dealer says "do you want us to fit it for you", they are going to charge you around £250+VAT for the privilege of taking half the centre console apart. For a full description of the process of replacing it, check out Dave Sparkes' article on rangie.com.

[edit] Changing Pollen Filters

The pollen filters in the P38A are a service item, but don't always get changed, especially by non-main-dealer servicing agents who don't always know where to find them. If they aren't changed then airflow through the system will be drastically reduced, resulting in poor heating and cooling performance, and potentially putting higher load on the heater fan.

Checking and changing them is pretty simple. Lift the bonnet at look for a "letterbox" shaped cover at the ends of the panel at the back of the engine bay. Unscrew the cover and pull out the filter, making a note of the orientation as the replacement will only fit one way.

http:/images/new-pollen-filter-location.jpg http:/images/new-pollen-filter.jpg

The old filter was pretty dirty - at this point the performance of the heater was pretty poor. Don't let yours get this bad.

[edit] Viscous Fan Problems

Yves Bellepeau reported a suspected problem with his 2.5 DSE being very noisy when first started. The suspected culprit is the viscous fan coupling. Dave Sparkes offered these thoughts on the subject...

When the engine is cold the fan coupling is much stiffer than it should be, thus the fan turns very fast, moves a lot of air, and makes a lot of noise. When the engine goes faster the resistance of the air drags against the fan with sufficient force to free off the coupling, so it starts to slip, as it should do. As the engine gets warm this also allows the coupling to slip more easily.

It is always difficult to test a fan viscous coupling because it is difficult to measure the turning torque. Be aware that if stood overnight, all the fluid in the coupling collects in the lower half, and makes the coupling stiff. This is normal behaviour. Open the bonnet WITHOUT starting the engine. Try flicking the fan round with your fingers. It should move about 3 blades round. Your fingers will probably leave clean marks on the blades, so give it a couple of flicks, then turn it slowly backwards to count how many dirty blades there are between the marked ones.

If your coupling is stiff obviously you will not get this three blade spin. (3 blade spin = clean, dirty, dirty, clean, dirty, dirty, clean). After removing your fingers !!!, start the engine, there will be a lot of fan noise. When the engine has been ticking over (on standby) for a couple of minutes the oil is dispersed, via centrifugal force, into its proper place, and the fan makes less noise. Just stand near the engine bay and listen. By holding a hand above and slightly to one side of the gap between radiator and engine you can also feel the change in airflow as the coupling starts off stiff, and then begins to slip more. Stop the engine and try the finger spin test again. I don't know what you should get, but it will feel obviously easier to move. That is what normally happens.

I suspect with yours you can leave it at tickover for 2 or 3 minutes without it making a lot of difference. Once you have stopped the engine and done the second finger spin test, start the engine again, and this time rev it up, or close the bonnet and drive the car around until the fan quietens. Then try the finger spin test again and you should feel the lower spin resistance.

If I am correct this fault is unusual, because these couplings normally fail by slipping too easily, and the engine then overheats, especially if it is a V8.

If you do come to change the coupling, remember the nut has a left hand, counter-clockwise, thread. Please let us know what you find.

As far as I know that the viscous coupling nut is only a LH thread on the Diesel engine - it's a RH thread on the V8.

There are two Land Rover tools needed to get the thing off. The first, LRT-12-094 is a basically just a big enough spanner, and the second, LRT-12-093, is an even bigger spanner with some holes drilled through the end. These holes fit over the nuts on the crankshaft pulley to hold it in place. These tools should be available from normal LR parts sources, a main dealer, or the <a href="http://www.spxuk.co.uk">SPX UK web site. SPX are cheaper than getting them from a main dealer, though I have heard of long waits for parts.

Update

Much discussion on VCs on various mailing lists has lead to the following additions to Dave's excellent information. Contributions from Ron Beckett, Franc Buxton, and others.

David: Having visited the page you referenced below, I went Googling to see if Imperial did a smaller fan. I didn't find a web site for Imperial , but I did find several references to people using the products. One of these was http://www.iatransit.com/news/fans_maintenance.htm which I found fascinating, in that it showed a maintenance department doing exactly what we are doing. Mind you, they have had to change 15 electric fans 'this year', and by sourcing locally, they save $100 per fan. Even better, it gave chapter and verse:

"The fans ...... are distributed under the Imperial Automotive Products brand. However, it appears that they are actually manufactured by Hayden Automotive that is an American company that manufacturers automotive coolers and condensers". Note these aren't the same Fans and Viscous Couplings used on the Range Rover V8, but it is the source of IAP items which is important.

Anthony Brooks sourced a cheaper replacement for his 3.9 rangie:

The fan is Imperial 220618 (actually got it from Autozone.com), the flexalite fan clutch is FLX-5555 (again, I don't know if this will work) and there's an Imperial fan clutch that may work as well, part # 215049. Again, I've no idea about the clutches, but the fan did work on my '89 RR with 3.9 and not too surprisingly it looks like it'd be fine on the defender (also with 3.9). Oh, and when I replaced the fan, the original plastic one was in bad shape; it'd started to develop some small cracks.

STOP PRESS! I just discovered that my car (1997 4.0 V8) uses a 36mm nut, not the 32mm on some other variants, and is a right hand thread - or, at any rate, turn the spanner anti-clockwise to remove. To hold the pulley in place I used a 18mm ring spanner around one of the pulley bolts and held against the central shaft. Any spanner with a long shaft, larger than the pulley bolts, and with the ring "in line" with the shaft rather than angled should work.

[edit] Fitting Kenlowe Fans

I got this information from Jonathan Clark in Stockport. Jonathan was concerned (as I've heard from a few other owners) that the existing electric fans weren't coming on enough. I can only say I've never had a problem with the existing cooling, though in the UK I don't really see extremes of temperature.

I have finished installing a Kenlowe electric fan kit this morning. Its a dual 13 inch kit which replaces the viscous coupled fan and comes with wiring kit, adjustable thermostat and two relays. The viscous fan was getting a bit tired and the other day (which was hot at around 30 degrees C) the aircon was heating up the engine a lot.

I know that the aircon fans can operate at full speed to supplement the viscous fan, but on this car I am not convinced they work. Also, getting any additional fuel economy is a bonus (Kenlowe report up to 8.5%.. we will see).

In case anyone is considering the install, it took me about 6 hours. About 4 hours of this was making the necessary brackets and fitting the fan assembly. I would imagine the average DIYer would have given up and take the car to a garage..

Without the workshop kit I have (drill stand, angle grinder, metal cutting jigsaw, vice, etc.) it would have been even slower! With the metalwork provided I did the following to make the brackets to secure the fan vassembly.

[edit] Removing old fan

Top of the cowl comes off easily enough. To remove the fan and viscouns coupling you are supposed to use the LR tools. I used an adjustable spanner which opened far enough (about 34mm) and a G clamp to stop the pulley from turning. You don't need to remove the poly V belt.

The bottom of the cowl was harder to get off. The main obstruction is a Y piece in the bottom hose which 'clips' into the cowl. This needs freeing before the cowl can be lifted out.

[edit] Brackets

1) Join the top and bottom rail section together and then colt the top one to the fans. Cut the bottom piece of frame (rail) at both ends to clear the pipework (power steering?) flush with the end of each fan. I did this with an angle grinder although it would have been easier if I had done it before bolting the fans onto it.

2) Mark and then cut a section about 15mm deep out of both metal fan ducts to clear the edge of the rad. This is neccessary as the dual fan assembly is slightly wider than the rad. You need to remove the plastic edge finisher from each one and then cut and refit it afterwards. I used a jigsaw with a metal blade to do this.

3) Make brackets to fix the top rail onto each side of the rad frame by cutting and then bending two of the L brackets into a Z and drilling then bolting onto each end of the top rail.

4) Make a bracket from one of the U shaped pieces with two L pieces bolted to it to fix the bottom rail in the middle. The U needed about 30mm cutting off each end. Make sure you then file the sharp edges off so you don't damage the rad during fitting. All of these brackets needed the angles adjusting by mounting in a vice and hitting with a hammer. This is so that the bracket angles from the bottom fan assy rail towards the front of the car to be bolted onto the brackets on the bottom of the rad which secured the old fan cowl. Use two of the M6 bolts to fix to the bottom fan rail and two M6 on each L bracket. All these holes need to be drilled. I drilled and fixed the U piece and then marked the L brackets in situ and then drilled. The bottom of the Ls fix to the rad using two of the bigged bolts. You will need two additional M8 plain washers here to go below the rad bracket as its plastic.

5) Using a left-over piece of one of the L brackets cut for the top mountings, Drill six holes in it. Four are 6mm to relocate the power steering reservoir about 25mm to the side, and two are 4mm to mount the bracket for the thermostat. I used 2xM4 screws to mount the thermostat bracket.

[edit] Thermostat

This mounts using its bracket onto the custom bracket also supporting the power steering reservoir. I fixed mine the wrong way round and only found out when I put the knob on it. The capiliary tube should come out of its body at the front of the car so that the knob markings line up with where the securing screw goes once its preset. I had to replace the standard spring clip of the top hose with a worm drive clip as the spring one does not seal properly with the capiliary and supplied rubber block at its ends. I also used some gasket sealant to make sure.

[edit] Wiring

You will need two 30A fuses, a 15A one, (all spade type) and various crimps. The kit comes with crimps, but not the type for my crimp tool so I used what I had (blue/yellow ones).

I wired the power for the fans (switched by the relays) back to the under bonnet fusebox main feed from the battery (under the rubber cover) and routed out with the main battery lead. I mounted the relays on the back of the battery cover which is close by. I also used the ground connection below the fusebox for the ground feed to the two fans.

In contrast to the Kenlowe supplied wiring diagram, I switched the ground of the relay coils as this results in less wiring. I picked up a ground connection next to the thermostat using with a ring crimp onto a convenient bolt, but not from the thermostat bracket as the rad is isolated from the chassis. The power to the other side of the relay coils was fed from the same permanent main feed as the fans, additionally fused at 15A. This arrangement means that the fans can run after the engine is switched off. I have yet to see whether this causes problems with the alarm! If so, I will find a switched feed to send to the relay coils.

For a shade under GBP300 I would have expected Kenlowe to supply custom brackets, I also needed fuses, cable ties, a worm-drive hose clip and had to make a bracket to slightly relocate the power steering reservoir. Still, end result is good and I feel much happier about the car's cooling ability.

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Buying - Models - Servicing - Enhancements - Powertrain - EAS Electronics - Brakes - Interior - Exterior - Security - Heating - Manual