All posts by drobinson


The amount of oil the provent collects will only be an average, it will vary between engines, mileage of engine, etc etc..

The biggest issue with a modern common rail diesel engine is not particularly CCV (Crank Case Ventilation) recirculation or EGR (Exhaust Gas Recirculation) its the combining of the two. The oily fumes of CCV and the dry exhaust soot mixing together that form a black sticky tar like product that collect in the intake, its the biggest cause of EGR, intake related faults, valve issues etc etc.

By isolating one or the other, using either method such as a provent or EGR blanking on upto early Euro 4 spec engines, or on later Euro 4 spec engines and Euro 5 doing EGR emulating or remapping to delete the EGR function is one of the biggest positive things that can be done.

Personally I tend to go with EGR blanking, deleting through remapping or emulating to be a better solution as it also removes the by product of exhaust gas being “re-used” in the combustion process, thus leading to cleaning more efficient combustion, which in theory should give more power, but more positive will give better fuel comsumption and a longer lasting engine, of course when combined with regular (10,000km) oil changes and air/fuel filter changes, again at that 10,000km service interval.

Just food for thought, nothing more.
A provent is one positive “mod” to do for very little cost.


The JK Wrangler is particularly sensitive to mis alignment, as in the wheels, A lot more sensative than a lot of other vehicles that I work on that one might perhaps think would be far more sensative than the truck like JK Wrangler, such as new Range Rovers etc etc. I resolve a lot more of this on the JK just by getting the wheel alignment done properly, as in it does need to be just about spot on.

The biggest cause has been when the vehicle has been somewhere and got “the big lift kit”, had “heavy duty u-buet” steering arms etc etc and large tyres, it seems most stuff up the adjustment when they do the alignment badly (well in Perth anyway).

While this doesnt help everyone, I use Bob Jane in Victoria Park (Perth W.A) and they never have an issue because its a “Jeep” or “Land Rover”.



The Defender TDCi fuel cooler placement on the inner passenger side of the chassis, while from an engineering and purpose point of view it’s in a good spot for air flow and doing what its designed to do.

But… it does seem more prone to getting damaged and or the fuel lines attached to it by branches, logs etc etc. I have heard of people removing the fuel cooler to fix the issue of getting damaged, quite simply this is a bad idea.

The fuel cooler, its purpose/reasons on any common rail diesel is (in the most basic explanation):

*Diesel engine power will be typically measured at fuel temperatures of 50 C (deg C), the higher the diesel fuel temp, the less density it has, less density, less power.
*A typical common rail diesel on the high pressure side of the fuel system will be around 30,000psi, high operating pressures cause excessive heated diesel.
*Diesel fuel is also used to cool (and lubricate) fuel system components, so the fuel also acts as a heat sink (heat exchange).
*Most common rail fuel systems have a high volume of fuel going through the fuel circuit, aprox 80% of fuel delivered to the engine goes back to the tank via the return line.
*The fuel cooler (heat exchanger) is what removes excess heat from the return diesel fuel, airflow also aids heat dispersion.
*The coolant lines connected to the fuel cooler, or rather the “Heat exchanger” are not at that coolant temperature of 80 – 90 deg C, but (like a lot of the cooling system) are typically round 50 deg C.
*The coolant removes excess heat from the heat exchanger.
*The cooled return diesel fuel can be round 40 deg C.
*The cooled return diesel fuel temperature will be closer to that of the fuel in the tank.
*The less differential between return diesel fuel and whats in the tank reduces the possibility of condensation.
*Cooler diesel fuel improves efficiency in combustion and reduces emissions.
*Cooler fuel in the tank reduces overall tank temperatures, with reduced radiated heat through the body.

The simple fix is fit a fuel cooler guard manufactured by APT Fabrications.  There is a link over on my webpage under the Contact Us (or in this case, them…)



The Jeep KJ Cherokee has a factory TPMS (Tyre Pressure Monitoring System), this is all very nice but they arent known for being particularly reliable, some of us simply don’t want this function, sensors need to be replaced by genuine and if you change to a steel wheel I believe the TPMS wont function anyway.

In the U.S its a mandatory (legal) requirement and a dealer prolly wont disable this function. In Australia its not a legal requirement. I was told that “only a dealer can disable this function”. This is not entirely correct, but you will need access to a diagnostic tool that is capable of doing the programming function for each tire sensor.

In the pic below I am using the most awesome Snap-on Sollus Ultra scan tool (worth every dollar I paid). Once into the program function simply program in for each sensor listed the code 22122212 your done baby! Now enjoy no errors on the EVIC or no idiot light.

On a Jeep KK Cherokee (the model after the KJ) its uses a more standard type of computer programming, as in a simple in out code, so use the code 00000000.



As we all know, you don’t re-use nylon locking nuts….

The retaining nuts and bolts for the prop shafts on all Land Rover Series, Land Rover Defender & Land Rover Discovery 1 & 2 models are a 3/8 UNF thread. The original factory nylon locking nut thickness are a odd thickness. You can either purchase standard thickness retaining nylon locking nuts or thin nylon locking nuts. In most applications using the standard (but thicker than the original Land Rover nuts) will be fine.

On some applications such as on a Land Rover Discovery 2 front output prop shaft the bolt length are too short and the thin nylon locking nuts must be used. If you use the thicker nuts the thread on the bolt wont pick up on the nylon part of the nut enough to secure it.

The picture below explains it all. From left to right

Thin 3/8 UNF, Land Rover 3/8 UNF, Standard 3/8 UNF



In the previous post FUEL FILTER HEAD REPLACEMENT we looked at the fuel filter head replacement on the Jeep KJ Cherokee CRD.

On the later Jeep KJ Cherokee CRD 2.8lt it uses a later black (plastic) style fuel filter head, this head is also prone to leaking. If replacing the later black fuel filter head you need to wire in a resistor to the fuel filter head temp sensor. This is pretty easy.

The pics are in order and have a description. Keep in mind this mod is for Australia where a fuel heater is not needed.


The Jeep KJ Cherokee CRD fuel filter head is prone to leaking, both on the early metal looking style and the later black plastic style. The genuine replacement head are expensive. The symptoms are as listed.

  • Hard starting.
  • Stalling once started.
  • Random cutouts while driving.
  • A code may or may not be listed, if it is it will be something along the lines of “P0093 = Fuel rail pressure malfunction positive pressure deviation”

The pic below is the replacement fuel filter head that can be picked up from most filter suppliers. In Perth W.A I use Filters Plus. The cost of the head is round $50 and is a permanent fix for this common issue.

EARLY FILTER HEAD: On the early Jeep KJ Cherokee CRD (thats the metal looking head) you need to extend the length of the fule hose that feeds from the outlet of the head that goes to the intake of the high pressure pump.

LATER FILTER HEAD: On the later style of filter head (this is a black plastic looking one), the original fittings and fuel hose can be used. This pic below is of a later fuel filter head replacement job.

On the later style of filter head, you will need to wire in a resistor as a replacement for the fuel temp sensor, this is cover in another post, look for FUEL FILTER HEAD RESISTOR MOD”

In both the early and later style filter head, once replaced it will use the fuel filter as used on the later style. I use BALWIN BF7970