So here is a question, Has anyone tried modifying the X351 3.0d?

I've just finished a schedule of works on mine and now have a lack of a CAT, no EGR and Stage 1 on the engine. It now goes like a demented beast but occasionally pops up with "Restricted Performance" which I reckon is a leak somewhere or other.

The only thing I am now lacking is the Gearbox remap and some better brakes. Does anyone know of any Braking upgrades that will fit?

Thanks

Garry

 

Garry, you should be able to get the brake calipers and rotors off of a 5.0L supercharged car and put those on your car. Of note, you need to get everything!!!! calipers, pads, rotors, the mounting brackets, bolts, EVERYTHING!!!!. About the only thing you do not need is the front spindle. That will give you 1inch (2.5 cm) larger brakes which will make a big difference on your car. Granted, of note, you will need to make sure that you are running 19" rims at a miminum as I recall. Anything smaller and the brakes will not fit. So, keep that in mind.

 

Thank you for that Chris

That was exactly what I was after! I have the 20 inch rims so those should fit nicely. Now to find out where to buy them all from :-)

With great speed comes great twitchyness when you come to have to stop

 

The tune alone is enough, you don´t need to remove EGR. In fact its good to cool down combustion chamber when driving "light foot", what is main purpose of EGR on modern engines. EGR closes anyway then power is required from engine. Nor either you don´t need to remove CAT / DPF for more power: The flowrate of these are far, far more than 3.0 litre engine can push thru with its max rpm. This of course as long as they are clean... You need to remove CAT / DPF if you are plannig to use ~7000 rpm/min -> Dont try it: rods will let go far less.
For sure you will get more sound without CAT / DPF, thats the gain, and if your engine are working without issues and the tune is made correctly, your car should still pass the MOT smoke test without CAT / DPF in present.
I have seen some have replaced the last silencers with straight pipes. This also (even made alone) make a big difference for exhaust sound.
Been heard that one fellow who are working on engine tune shop have been taken up to 380HP / 880Nm from XJ:s AJD-V6 3.0 litre diesel engine without issues (CAT / DPF still in present), but i heard it start to be limit of everything on engine and driveline. (obiosly engine olis need to be changed "often") With that tune, with very flat power curve, ~700Nm available already as low as 1100rpm, diesel XJ should be near in level to be faster than 5.0 SC V8. Note: By my knowledge this is not tested in real life and just an estimation.

 

I dont like the EGR at all, it pushes junk back into the engine that then impedes the burning of the fuel. I liken it to standing behind a truck and trying to run. I burn my fuel better and in turn produce less carbons this way (or thats my logic)

380bhp, now that there is a trippy number. I did toy with the idea of not removing the CAT from the tubes but I thought that while I was there this may help somewhat

The result of the tune and the work is noticeable but I havent rolling roadbed it, as I dont want the extra strain on her

Amazing these engines, great big power plants that do nothing but impress me

 

Oukey...
Think about again: EGR(s) are open (path to the inlet manifold) only when engine are in low power "lean" mixture mode exsample when cruising highway. Not much fuel injected and burning process is accuracy and very good. Even too good because fuel mixture have lot of oxygen and only small amount of fuel. Thats why EGR(s) are opened on this mode (and only in this mode): To replace part of the oxygen rich air with exhaust gas, where oxygen have already burned away. This will keep combustion chamber, valves and piston in lower temp. (hot combustion/piston/valve issue bit later) So, tiny bit of fuel equals tiny amount of particles to enter inlet manifold when running EGR open mode. Right?
When driver push the pedal for more power, more fuel is injected and EGR(s) closed. Now engine have more fuel to burn generating more particles, but ERG(s) are closed. -> No particles enter to inlet at all. You follow? ... Well, above of cource when everything works correctly...
So, no gain on fuel economy, nothing to do with it, or no carbon emission gain by removing EGR. Instead your NOx emissions rocketed sky high by exessive combustion temperature in lean mode. (exept, if your tuner have noted EGR delete on his fuel charts and set the mixture bit higher for lean mode. Thats a correct way to do it. -> It will increase fuel consuption. but it is better for engine.

There are many reasons why above EGR process don´t work even in brand new engine. Lousy engine managment coding, crap injectors or measurement sensors, too light springs or play in gearing on EGR valve are just few known issues right from factory in certain models, causing ERG to be open when it should be closed or heavy particle generation even in lean mode.
Also if fuel injectors don´t atomise the fuel spray for combustion like they should, there will be droplets and these don´t burn complete causing increased amount of particles and oil dillution by unburned / partly burn fuel passing piston rings, The particles for sure then end up for inlet when running in EGR open mode. Dirty fuel filter, low quality fuel, injector, faulty or inaccurasy fuel rail pressure sensor etc can cause poor fuel atomisation. Carbon deposits passing piston rings ends on engine oil, causing wear for bearings and seals. (worn seals on turbos cause more oil to enter inlet)

The "goo" on inlet manifold is mostly from engine oil. The breather will past fumes from crankcase to the inlet manifold and these fumes have oil particles on it. Oil particles "cook" on inlet manifolds making thick black goo together with exhaust particles from EGR. Exhaust particles themself dont stuck as thick goo. The -80:s/-90:s diesel engines did not had thick layer of goo in their exhaust, even smoke was great and black these times. Therefore is important to use Low Ash engine oil -> Oil will stay running format and do not "cook" on inlet channels as easy as standard oils. The oils nowdays are great mix of different chemicals and hydrocarbons. Modern oils have strong molecyle connections for stress and viscosity, but they also change their form and lose their charasterics fast if conditions arent optimal. -> Biggest enemy for molecyl connections is fuel, because fuel including solvents keeping it thin and running. Shortly: More fuel in oil, more fumes and more "cooking" by lost charachters of oil.

Hot temperature is another enemy for engine oil. Remember increased combustion/piston temperature issue metioned earlier? Yep: On diesel pistons are cooled by oil spray from underside and cylinder head have oil channels. -> You quess now what happens when you remove EGR and incrase the combustion temp? Correct: Your oil temperature rises. Again more fumes and because crackcase breather past oil fumes to your inlet manifold you actually made situtation worse. (maybe, lot of variables here, depends the charts as well) Hot piston / valves / combustion chamber surfaces also make particles to stick on them, so piston head, combustion chamber and valves can be soon covered by black carbon layer. (every engine tuner knows that hot surface are like clue for carbon deposits) Again maybe, because there are lot of variables.
Hot piston can also cook engine oil to the piston rings and stuck them. Then combustion gasses with unburned fuel blow thru to the crankcase... You quess? .. Yes: Even more fumes to the inlet manifold!

Note: None of above might not nessesary mean that you are in trouble or your engine suffers any of them. Don´t panic! Your engine might run as smooth and nice forever, because there are lot of variables. Tons of them. This is only in worst case, unfortunaly real for some engines right from desing board (read from Price engine, used exsample in early New Mini:s?) The 3.0 litre AJD-V6 engine is made with great knowhow by Ford/PSA with some tolerances to work as it should, exept it designed to fit in front wheel driven PSA vehicles, so they made it as short as possible. (big mistage: Bearings are bit too narrow, so take good care of your oil and mount your oil filter by correct way! This is extremely important. Check the thread of diesel oil filter drain valve on Diesel versions section on this forum main menu)
As you see, many things come back to the engine oil. Up to that many parts in modern engines are made by plastic. (inlet manifolds, chain guides just to mention some) Oil make plastic britlle. This is why engine manufacturers work together with chosen oil manufacturer so they together make chemically as neutral combination of the oil and plastic type used in engine. Therefore it is recommend to use oil brand manufacturer have been working on. "Fullfill" requirements does not nessesary mean that it is chemically neutral and can cause issues with plastic parts. (cracking inlet manifolds or chain guides) There is no savings, engine oils arent expensive if you calculate price/mile you get out of one oil change. (well, depends where bought)
I have seen many local tuned BMW diesel engines, where things have rocketed south fast after EGR / DPF delete and tune. Everything went opposite than thought. (might be tuner error as well, not knowing what need to be done for succesfull tune?)
Most of them have aftermarket "cone" air filter too, sucking hot air from engine bay instead of original air intake front of radiator. -> Even higher temp for inlet/combustion for oil to cook down everywhere.

I have been racing long time with different cars in past and broke (too) many engines back then. Some were driver errors, some engine builder errors. Both me, so have to dive in and seek the reasons and learn what causes what. (for driver errors there were nothing to do...lost case ) When engine running flat out on its peak power whole race distance, small details matter (can be costly and usually happens fast)

For referense: My 2010 XJ 3.0D have all original EGR, CAT / DPF in place. Been only used Castrol C1 low ash oil with 10k km change interval, and twise a year Lucas injector cleaner fuel add-on for 3 full tank in a row. I clean the MAF:s and MAP once a year since owned it. (6 years now)
My XJ are used 60% long distance highway / 40% short city driving. Last autumm i used endoscope to check my inlet manifolds for the situtation just for curiosity, and it have only very thin layer of coating on them, no accumalation seen anywhere exept some around end tips of the metal pipes inside of throttle body what injects the exhaust gases in. Wiped it clean. ( i could not reach as far down to see valves. It would be interesting to see them too)
My XJ have now 316 000 km on odometer. (197 000 miles) Last MOT smoke test was 0.01, so DPF is still working well.
I claim that if everything is in order and working correctly: The EGR(s) are not a problem on 3.0 litre AJD-V6 diesel engine.
(as long as they and other related systems work as they are mentioned and correct oil is used)

Yes, 3.0 litre AJD-V6 is a very good engine. Better than its reputation. (oil filter housing drain valve can be one reason for many bearing failures)
Everybody are surpriced how efortless old big cat moves when just lightly requested. Even engine start to be bit old desing, comparing some newer ones with 3 turbos etc.
It have its flaws, but when taken care its Ok.
Enjoy your car.

 

Yep, any Jag fitted with OEM 355 mm front and 326 mm rear brakes (which I am sure the OP's is) will accept an upgrade to the 380 mm front and 376 mm rear brakes no worries and it is a fairly straightforward plug and play bolt off bolt on job. Just swap over all the hardware as you have listed (plus splash shields) and no need to change any brake lines etc.
With wheels/rims if sticking to OEM Jag you will need 20" to clear the front brake calipers, the only exception is F-Type 19" which will fit.
The hard part is finding all the parts at a reasonable price, you will need new rotors/discs and pads for sure but the rest (calipers, brackets and maybe splash shields) can be found used at a fraction of the new price. The 380 mm front brakes are identical across all Jag models so don't restrict yourself to just XJ but the rear brakes can vary/differ across models, XJ and XF are the same but XK and F-Type are different (except for the rotors which are the same across all Jags.).
Another tip - many sellers of brake parts especially brake pads are extremely vague about the exact description of the brake size, you need to make 100% sure you are ordering/buying the right type and size parts, make sure they are 380 mm for the front and 376 mm for the rear, if not sure/clear check with the seller first.
You CANNOT mix and match parts across brakes sizes!

 

Thanks for that OzXFR I think what I'll do is look for a Cat B (I trade a bit) and strip it off the front. Hopefully it didnt get the Cat rating because its brakes failed :-)

 

Thank you for the comprehensive reply Vasara, I can see your point on a lot of the stuff and understand it is through a lifetime of learning there!

So from my side I dont understand why pumping exhaust gases back into the engine will help with the fuel economy, I too have several cars that have surpassed the 200k marker (in the UK so Miles) and have found that without the EGRs they both have less trouble and also you dont end up with gunky EGRs to clean out every 20 or 30k miles. I also find there is a distinct increase in power and fuel economy by doing it. I'm not known for my tender right foot and understand that due to enjoyign the power there will be greater bills around the corner.

I've taken on board your advice about the lean mode, I'll see if I can get that done. The chap that did the Stage 1 was new to me and not someone I normally use. I wasn't impressed with his knowledge to be honest so I am looking to get it checked out again

Again thanks for the reply and for the comprehensive information I really appreciate it

 

Hi ImNotJohn,

No problem. Been learned hard way and i believe knowhow sharing. This forum have been helped me a lot and i want to give some back if i can.
There are great members here.

The most common misunderstanding about EGR is the reason it have been added for the engine: Its there so engine can be runned with extra lean mixture for saving fuel. To prevent damage for extra lean mixture, part of the oxygen rich air is replaced by exhaust gasses thru EGR valve. Also too oxygen rich burning process create high amount of NOx. Problems start, like you wrote, in high mileage vehicles, if and when the system is not working correctly anymore. (unfortynally some engines are known not working correctly by EGR part direcly from factory... shame on these manufacturers!)
Not sure how far in lean side JLR have been went with AJDV6, so cant say for sure when or if there will be problems or not. I believe in normal community and mix drive you are very well Ok. Remember: The EGR open only in situtations where low power is needed from engine, exsample highway cruising. EGR is closed when power is requested. (or should be closed) City driving is mostly acceleration and decleration. Therefore if any engine got intake sooted during city driving, there are someting wrong in the valve (it leaks or stuck) or its programmed wrong. (open in wrong time)
I know tuned and EGR deleted AJDV6 engines been running without problems hudred thousans of miles but its all about the fuel charts. If EGR is deleted, its wise to adjust lean mode chart. (and this is how and why owner feels engine snappier after EGR delete. The engine do not enter anymore to the lean mode. Thruth is that EGR delete alone do not make any difference for power. Valve is closed anyway when accelereted. (or it should be closed)

Of cource if the EGR valve have been leaked and after its deleted and bloked, the engine will work better, but so it does after any other fault fixing. (vacuum hose leak or dirty MAF / MAP )
Good idea to recheck the tune.
Btw: Its not only Diesel engines. EGR works exactly same way and purpose on gasoline engines as well.

Farest i have been driven with plain factory setup is 2.2D Peugeot 607. It had +530k km (+331k miles) on clock when i let it go. (for to next owner)
I also had an big Citroen Jumper van for my hobby, also with 2.2D, but not same family than 607 engine. Van that had about 440k km (275k miles) when i past it for next owner, but that had EGR changed at least once. EGR failures are quite common on these vans. EGR will stuck open and soot will be evertwhere if not fixed fast.

All the best: Enjoy your XJ !

 

Guys…. Another technical question for you.
Way the egr works
Egr opens on different moments…to recycle gases.
My question is:
He goes full open from full closed? Or has intermediate positions? More to be precise…… is just a 2 position switch or….. It permanently adjusts based on requirment of the car?
On Jags and other cars.
And….. If it has low voltage due to.….. Lets say….. Wire chewed by rat…..and half of the wire being practically gone in thickness…… could that make the egr go only from fully closed to fully opened…. With no intermediary function?
So….in short…. Its like a switch on of or like a potentiometer? Its adjusts?

And…. Pretty much the same question with an injector.

Why the question….
On a diesel….. Bout of the aspects presented.
Could cause, randomly, at acceleration and deceleration.… jitters and noise, because of starving either of air bysudden close of egr of fuel on sudden flowloss through injector?
Maybe sometimes it has enough electricity to operate properly….. Maybe sometimes they are under voltage and suddenly close…. Both cases.

Under fullaccelerations…… fullbeans…. Not one hiccup. Nothing. Never. Ever ever ever. Because maybe charge is optimal and all works. Regardlessthespeed to start the acceleration! Not from 0 to max speed. Not in kick down. Nothing.
But once you start to drive…. Normally….. Jitters at deceleration.…. Like its choking.
And driving….100….130 kph….. Sometimes is good…. Normal sound, but sometimes becomes noisy….. Increase engine noise. A bit rough sound.

Oil clean, fuel clean filter changed, iddlenormal…. But jitters when cold and with rev matter jiggling harder with electric seats on and smaller jiggling with electric seat off( seems to act better with less electrical consumers) . When hot…. Jiggling is almost gone.

PS : IMPORTANT! This situation with idle is for years. Soma asta the wire situation. But it has been getting more jitter like its choking…. More pronounced… and felt through the chasy. Just changed the gearbox and motor mounts. Next is the intermediate propahaft bearing. The sound is still there….. Some times. No matter cold or hot…. At declaration it feels like it might choke. And sometimes….. Not that hard, at frequent gear changes in 30…60 kph. Egr not adjusting properly? Air valve control not good ?Missing power even when driving and not being consistent? Same questions on injector

It SEEMS that, on normal drive….., gearbox like to upshift to low rpm…… and then the noise starts. Humming. On full throttle…. Not. And in engine braking….. Same humming…. Bigger as it decelerates…. With… sometimes big… sometimes verry few shakings until you press the brake and stops.
Injectors done at professional shop.
Rpm at cold….. With climate on…750 rpmish….. Without climate at 450 ish


Ps2: not having any computer errors what so ever….. For a long time……. No shop could identify the problem
And now I think the jitter getting worst in frequently and amplitude is killing engine mounts and gear box a lot sooner

 

The EGR valve(s) main purpose is to replace excess oxyden, in low power output events, with exhaus gasses where oxygen is already burned off. With this less amount of fuel can be distributed to the cylinders without fear of meting parts by too hot combustion. Most of modern diesels, like x351 the EGR:s are controlled by PWM signal by ECU and since they are not just Open/Close valves. Note: When everything works like engineer have designed, EGR:s are open only when very low fuel is burned so soot accumulation on EGR shall not be any issue. However: There are lot of reasons, many directly from desing board, why soot accumulation can be high. Basicly for some reason the EGR stay open or leaks when it should be closed.
You might have jamming EGR. If its leaks when it should be closed, there will be less oxyden in burning process (rich mixture) causing black smoke and eventually block the DPF. On x351 the EGR:s are direct driven so the actual position can be read by diag SW - As long as the calibration is accurate. The EGR calibration is done by diag tool SDD by a single task or Full Vehicle Reset function. (disconnect-reconect battery do not start the calibration) When activated both EGR:s run full cycle 4-5 times.
Injectors works same way. They are behind of very fast PWM control under ECU. They spray multiple accuracy measured layers (up to 7!) of fuel on each compression cycle.
Possible reasons of your issues:
EGR: You might have sticky EGR:s. They could operate Ok on full open and full closed, but tiny adjustments might not happen and then mixture is away from optimal. Solution: Clean or replace.
Injectors: You might have dirty/sticking injectors. Try some diesel fuel addon, like Lucas upper cylinder lubricant. Also possible that fuel rail pressure sensor is playing up. (output value need to be compared to the mechanical meter)
MAP pressure sensor blocked. Very easy check. Top of the engine. One screw.
Sticky/swallowed air intake shutoff valve on throtlle body. This is also very easy check or fix. Caused propably by usage of wrong engine oils, resulting air shutoff valve to swallow and sticking. Take intake air hose adapter off from top front centre of engine and close the valve by finger. If you feel that it sticks on closed position then need to be sanded down or replaced.

 

Just read your edit:
To add my previous reply: Your 450rpm on idle is too low. ECU should detect that and correct. Do you have std ECU or modded?
You can try to swap MAF:s positions. They are identical and as one is for primary turbo and other is for secondary, the primary have measured approx 80% more air than secondary.

 

problem in discussion is on another car. Not Jag . An om646. But i simply don't have anyware to ask. Been to 6..7 shops. No error no problem. Damn it…. When at shop it runs…. Ok…ish. Kinda. But yes….. Same answer as applyable to all diesels. Egr sticky…… it is….. But I don't know if its gone the egr or has a bad wiring because of one wire chewed by rats a long time ago. Same case with the injector. Bad wiring…. Same motive. Injectors wore done at shop.… egr is sticky at start but after it runs normally when I checked with diagnose real time at a service shop. Most definitely I have to re do the 2 wires.…… that is a night mare to do because you simply can't find car electricians over here. Will do it myself…... . And check and clean.….. All the plugs I ca. Find on the engine withering loom. And after that….. Start changing sensors.……. Because again….. None at any shop can chef if a sensor its bad or not. Especially…… solenoid like pieces. Those are a big no no to check around here….. Because the break if they do. And that it's exactly the answer I got in 3 big shops. Imagine that.
So…. Like I told you…. I really didn't had anyware alse to ask for answers. All shops said the car works good

Thank you for the answers .

 

Ok.
I would start with wires. Damaged wires can work Ok when in shop, but play up when in motion. I would not do any other tests / work before damaged cables fixed.
Fixing cables with soldering is not so hard and no electrical needed. (forget abicos etc in vehicle)
Check this: (in EU the lead solder is history ~20 years by RoHS directive)
Soldering rule by three steps: Add heat -> add solder -> keep heat 1-2sek for solder to soak.
Simple soldering kit with some solder and flux with it cost 15-25€ in a local market. Cutters/stripper and some heatshrink and some wire wrapper shall end total less than 50€. Disconnect battery before start playing with wires to avoid shortages.
If possible remove the damaged cable harmness from vehicle and take it to table for better access.

 

thanks for the answer
i did some soldering before. Not a new thing. Nice tips in the video. Thanks again