Your questions answered: RRS oil dilution, Td5 cruise control and more...

Gambia garage

I am an independent Land Rover specialist based in Gambia where there is an ever increasing number of Range Rovers, Range Rover Sports, Range Rover Evoques and Velars. I personally have a slightly modified 4.6 Range Rover Classic and a 4.2 Range Rover LSE.

DPF issues: The biggest problem we seem to have out here is the dreaded Diesel Particulate Filter (DPF) causing engine oil dilution, which can destroy the engine. I am able to remove and map out the DPF, but not usually in time, as the problem is not known or understood out here. I always take a dilution reading of the oil first and check for sparklies [particles] in the oil filter. As you know, the dilution should be zero, but I have had them still running with 25 per cent oil dilution. Then there are those that are on three or four per cent and fail, very strange. They even fail after renewing the engine oil and filter as a result of the engine damage previously caused by the dilution. That can be difficult for the owners to accept, as you can imagine, so I have to explain the situation in detail to cover myself.

From experience, it seems that when a car starts to have a suspected dilution they send it to this country and some
unsuspecting buyer gets what they think is a good-looking car, and then they start to find out that it may not be as good as they thought. We get the cars in and have to tell the owner that there is a dilution problem and show them the metal particles in the oil filter, which shows the engine has suffered wear due to the dilution already. Changing the oil and filter helps, but it can’t fix the engine wear, and they have to hope the engine does not seize as a result. This is a very well-known problem, but I have to deal with the customers who are not happy about it. There are a lot of Evoques, Sports and others parked up with seized engines here: not good.

3.0-litre crankshaft clearance: I am currently doing a rebuild on a 3.0-litre Range Rover Sport (L494 model 2018-2022) with crankshaft bearing failure. I got a new crankshaft and after I fitted it (without removing the pistons) there was a clunking sound when the engine was turned, and it was quite tight to turn for about 150 degrees. I suspected bent valves, as there is not much else that could cause this, but I was not sure that the valves could either, with the rotation being so long.

Both heads were removed, and at every stage we rotated the crank to check if it was free – no difference. We found that one timing chain was snapped, so renewed both on the rebuild, but all the valves were fine. So we then removed each piston, and again turned the crank every time – no change. We got to a point where the crank was the only thing sitting on the bearings and still it clunked. We put chalk all around the webs on the crankshaft to see if it was catching anywhere, but it wasn’t.

We lifted the crank out and had a very close look at the cylinder block, not even being sure which end the noise was coming from. We could not see anything, so we looked closely at the new crankshaft, and saw a scored mark at the front of the front web, where it had been touching the block (pic 1). A closer look showed that the high point on the block casting (pic 2), had been ground down, but not ground down far enough, leaving a high point. The spot it was touching can also be seen. We then checked the original crankshaft, and saw the same marks on it, but not as bad. We got a grinder in there and took out the high point, and the crank now turns over as it should. I thought this was very unusual and that you may be interested, and pass it on to anyone else doing these repairs. 
Dave Paget, Gambia

Ed Evans comments: For anyone not aware, the oil dilution problem was first noticed on diesel-engined Evoques and Discovery Sports from 2016 model year. The Diesel Particulate Filter fitted to these (and many other vehicles) traps soot particles in the exhaust flow to prevent them being expelled through the tailpipe. The vehicle automatically detects the exhaust flow through the DPF, which will reduce as the soot accumulates. At a certain level, the car will automatically regenerate the DPF by introducing additional fuel to burn the soot and clear the filter.

This regeneration process is said to take around 20 minutes to complete at an average speed of 40mph. If the time span and speed cannot be accomplished (for example, when using the car only for short journeys in urban areas), the regeneration process will not be completed. However, before the DPF becomes blocked, an amber warning light will appear, at which point the vehicle needs to be driven at a suitable speed (when safe) for the necessary time to complete regeneration.

If an automatic regeneration process (not detectable by the driver) is interrupted, say by slowing or stopping, some of the unused regeneration diesel fuel finds its way to the sump where it dilutes the engine oil, with the potential to seriously affect engine lubrication. The degree of oil dilution is assessed by the car and, at a pre-determined level, the system will illuminate the service light on the instrument panel, requiring an oil and filter change regardless of when the previous routine oil and filter change was carried out. So this warning should not be ignored of the basis of a recent oil and filter change – the work needs to be done right away to protect the engine. There is potential for other models to be affected, according to the proximity of the DPF to the engine, Evoque and Discovery Sport being the most likely.

Regarding the 3.0-litre crankshaft concern, both the engine block and the crankshaft are cast components. Many castings are subject to minor variations on their unmachined surfaces which may need to be dressed. In this case a considerable amount of grinding appears to have been needed to clear the previous crankshaft web, and obviously wasn’t enough to accommodate the new crankshaft. It’s definitely one for engine repairers to watch for. Thanks to Dave for sharing this experience.

Defender Td5 cruise control

I recently rediscovered an article by Trevor Cuthbert in an old issue where he put cruise control in a Td5 Defender for around £20. I have seen various threads online saying that if the gearbox has been modified that it would not work. Well, my gearbox is standard but I have a Roamerdrive [overdrive] fitted. This unit is totally mechanical so I assume that, as the cruise part of things is controlled solely by the ECU, that this install should work okay. Can you please confirm? Phill K

Simple selection: the two switch buttons on Trevor’s Defender Td5 allow easy operation in comfortable reach from the steering wheel

Trevor Cuthbert replies: When the speed has been set on the cruise control on the Defender Td5, the ECU maintains the speed of the Land Rover until one of four actions is carried out by the driver:
• The clutch pedal is pressed
• The brake pedal is pressed
• The resume/cancel button is pressed
• The on/off switched is turned off

Each of these actions is noted by the ECU, and cruise control becomes inoperative until the resume button is pressed or the cruise control is switched on again and reset.

I don’t have personal experience of the Roamerdrive but, as you indicate it is completely mechanical, it should have no effect on the electronic function of the ECU and cruise control. The overdrive is simply adding some higher gearing to the drivetrain. Similarly, if I fit larger tyres to my Defender 90 Td5 (such as changing from the current 265/75 R16s to taller 255/85 R16s) the cruise control will continue to operate in a normal manner.

In both scenarios of taller gearing due to an overdrive or bigger tyres, it is assumed that the engine power and torque can cope with the gearing and terrain for the cruise control to be effective. For example, when I am towing a loaded trailer and the cruise control is set and functioning, as I approach an incline the ECU will try to maintain the set speed. However, if the incline becomes too steep there will not be enough power and torque for the speed to be maintained and the rig will begin to slow down. Before this becomes a problem with the engine starting to labour, I will naturally change down a gear or two anyway and, in doing so, depressing the clutch cancels the cruise control (the resume button needs to be used to get the speed setting back).

So, when you operate your Roamerdrive to gain higher gearing (and this operation has no electrical input to the ECU) I would expect the cruise control will increase the fuel to the engine in attempt to maintain the set speed, and will successfully do so if there is enough power and torque in reserve.

As you will have seen from the cruise control installation feature, the cost of the parts and materials is low, so if you are prepared to spend some time on it, I think cruise control will be very effective in your Land Rover.

Freelander 2 electric park brake

I would like to say how helpful the article that Ed Evans did in the December issue on the Electric Park Brake (EPB) on the Discovery 3 was, especially the part on the emergency release cable. Is the EPB the same set-up on the Freelander 2, and have you covered the EPB on the Freelander 2 in a past issue that I have missed? I would like to know how to find the emergency release cable on my Freelander 2. It’s a 2013 GS model which I have owned for five months and it is the first vehicle I have had with an EPB. I believe the interior set-up on the Discovery 3 is a little bit different to the Freelander 2. Doc Kelly, South Wales

Ed Evans explains: The Electric Park Brake fitted to the later Freelander 2 models is completely different to the Discovery 3 arrangement. The Freelander system is not cable-operated, and does not use separate brake shoes. Instead, an electric actuator is fitted to each of the rear brake calipers and operates the caliper pistons to push the normal disc pads against the brake disc to lock the wheels, and also to retract them to release the wheels. So, when you switch the park brakes on, or off, in the cab, a signal is sent to a park brake module which controls the application or retraction of the brakes.

Thus, there is no need for a manual release mechanism, and these systems are not known for jamming on. There is a method for releasing and deactivating the park brake, but this service mode procedure is normally only necessary when replacing the brake pads. There is also a procedure for releasing the brake when electrical power has failed, but again this is a workshop job, and not something a driver would do on the roadside. Most EPB issues on Freelander 2 are caused by incorrect installation/calibration, excessively worn brake pads or battery failure. In other words, keep the vehicle maintained by a knowledgeable garage, and there should be no problems.

Doc Kelly responds: I did not know the Freelander 2 had a different EPB system as I have been told to listen for a winding sound coming from the back of the vehicle when I apply the EPB. If it is not cable-activated, how do I go about adjusting it, or is it self-adjusting, and what should I look out for?

The newer Land Rovers are new to me. I am an ex-REME mechanic and worked on Land Rovers most of my army life and still do a bit of work on the Discovery 1, but they don’t have the electronics. I purchased a Haynes manual for Freelander 2 up to 2014 and was totally disappointed with it. There is no mention of anything to do with EPB. Could you possibly cover this in a future edition of your mag. I have picked up so much information in your mags over the years about the newer Land Rovers.

The relatively simple EPB (compared with Discovery 3/4) on Freelander 2 and more modern vehicles, uses an electric actuator mounted on each of the rear disc brake calipers to apply the disc pads

Ed Evans: The Freelander park brake is self-adjusting. In fact, the whole operation of the EPB is governed by the electronic module according to the state of other systems around the car, such as the engine, foot brake, clutch on manual cars, engine torque when pulling away, inclination of the vehicle when parked on a hill and, if you apply the EPB when the discs are hot, it will automatically adjust the holding force as the discs cool down. Of course, we never needed all this stuff and the handbrakes on early Discovery, Defender, Range Rover and Freelander worked perfectly well and were not known for causing problems; if they did develop a problem, they were easy to fix.

Having said that, modern electric park brakes rarely go wrong, but when they do the solution can be complex and expensive and require special procedures. If you do encounter a specific problem, let us know, and I and the team will do our best to explain the solution. In the meantime, I will look into covering the operation and servicing of the Freelander 2 EPB and disc brakes in a future issue of LRM.

Fasten your heat belt (Yes, heat)

I’ve been told by a friend that Land Rover is introducing heated seat belts into their top-end cars in the near future. Is he winding me up, or is there some truth in this? And what can be the point when the cars have some of the best heating and air con systems in the business?

Ed Evans replies: I haven’t heard anything about heated seat belts being introduced on Land Rovers, though they are being developed by the ZF company, a name more associated with transmission components on Land Rovers, though it has far more diverse interests. The heated belts are intended only for electric cars and, as Land Rover has announced no electric vehicles so far, I can’t imagine these being applicable at the moment.

Belting idea? This thermal image shows how the ZF belt applies heat to the body via conductors integrated into the belt webbing. It’s claimed they may increase electric driving range by up to 15 per cent

The idea is to give the car’s occupants direct heat close to the body right from engine start-up, such as we enjoy from heated seats. This is said to put less demand on the car’s normal heating system which, in the absence of waste heat from a conventional engine, uses electricity from the battery, thus depleting the car’s driving range. So the purpose of heated seat belts is to increase the electric car’s driving range in cold weather. Otherwise, I understand they look and function like a conventional seat belt.

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