Noob Diesel Questions

[Turismo07]

Hi,

Sorry if these are noob questions, I have read through the sticky's relating to diesels and in general have read the odd thread on the 2.5VM diesel, but have a couple of further queries.

What are they like to drive compared to the 4.0L petrol, or even compared with other turbo diesels?

Do they suffer from turbo lag? I recently drove a 3.0L turbo diesel manual 2001 Holden Jackaroo, and it was sooooo slooow even when the turbo kicked in, but before that there was a 2-3sec delay between putting your foot down and the vehicle actually responding to the throttle input... I also recently hired a 2012 3.0L TD Patrol (me and x3 other mates) and drove 9,000km trip up north and it also had noticable turbo lag (delay was 1-2 sec) but was quick enough to live with everyday (very thirsty though, 12-13L/100km all country driving..).

The diesel and 4.0L have similar touque figues (300nm) but will the diesel cruise comfortably at 110km/h loaded up with camping gear (some on a roof rack) with 2-3 people inside and say 31" tires? My 4.0L loaded up didn't like the bigger hills and if I was taking it easy (i.e. not putting my foot down and kicking the trans down a gear) would slow down to say 90kmh. Are the diesels similar to this or better/worse?

What scanner can you get to read the diesel ECU, or is there one avail that doesn't cost heaps of $? I read that the diesel requires a DRB2 scanner, is this correct? Will OBD2 scanner's not work? Will OBD2 scanner's at least show live info from the ECU (i.e. coolant temp, engine load, throttle position, etc) even if they won't read/reset trouble codes?

I've had a 4.0L XJ before and wish I didn't sell it now cos it was so sweet (well I knew it was at the time, but needed to sell for personal reasons), but then again it had everything done to it (i.e. all preventative maintenance and servicing, Commodore injectors, extractors, hiflo cat, clutch fan delete, etc). Now I'm looking for another Jeep, most likely a XJ and would like the fuel economy of the diesel and the fact that its a manual (much prefer over auto), and also cos I can't be bothered spending all the $$$ to get another 4.0L back to where I had my first XJ (and still only return 12-15l/100km between country and city driving with 31" tires, lift, roof rack etc). If the right 4.0l pops up in the next month or so, then I may still get it cos I know a lot about them etc and can fix it, but for know I'm considering the diesel.

Thanks :)

[Balkanac]

mate i have a VM diesel and my recommendation is stay away from jeeps alltogether, esp VM diesels. Very unreliable and a real PITA to work on. Diesels are delicate, heads are prone to cracking. This happened to me and it was $1300 per head to be recond and the thing has 4 of them. Ended up getting a brand new engine, $6k.
The srarter died on it last week, i had to get the engine mount out to get to it, which also needs replacing, $385 from Jeep. There is another place im waiting on an answer for.

Drive wise its great, i have to admit, it goes everywhere, no lag, you wont even know it has a turbo. Its not fast but its faster than a 3.0DiD 2007 hilux and nicer to drive. I did a lot of offroad tracks on idle. engage 4wd, 1st gear, slowly let the clutch out and it crawles on idle up the hills with 4 people in it. Unbeleveably capable offroad and great fun.

I see that you are in perth, you are welcome to have a look at mine once i get it back together :)

[Mudmonster]

the diesel are $$$ to repair but personnaly i think there great, i have brought 4 in the last few years
fuel econnomy stock tyres you are looking at around 10L/100k
im running 33's and getting around 14L/100

towing wise i have pulled 3.5t and pulls fine, dont know the load is there untill you come to a hill. fuel econy went up to 15L/100k
with about 2.5t trailer mine will cruise at 110k easy and it still has more stick

scanner you need a special bosch scan tool

i get a small ammount of lag due to my larger intercooler pipes.

[layback40]

From your questions it sounds like you are not a good candidate for a diesel. I have driven/ owned diesel cars/trucks/tractors etc for over 30 years. they are quite different to petrol cars. Your questions present as some one who doesnt have the type of driving style suited to a diesel.
Treated as a diesel, the VM is fine. if you expect them to behave like a petrol car, you will be disappointed as they dont. They are not a street racer but are a solid work horse. Like any diesel they do not take well to abuse or poor maintenance.
The engine in the TD is used in tractors stationary applications & boats as well as other cars. If looked after, not like a petrol, it is very reliable.

[Turismo07]

Thanks for all the info so far :)

I understand that the VM requires religious maintenance and I’m not saying I know all about it cos I would have a steep learning curve but I am in the habit of servicing all my vehicles every 5,000km and making sure everything is working as it should, if not better.

Whether I’m willing to take the plunge on a VM yet, which from what I understand has no fudge factor like the 4.0L has, is what I’m trying to decide as a trade off for fuel economy, manual trans, and good pulling power (torque) (which the 4.0L has but loses a little due to the auto trans).

I see that you are in perth, you are welcome to have a look at mine once i get it back together :)

Thanks for the offer, I may take you up on that :)

scanner you need a special bosch scan tool


Is this the ‘DRB2’ scanner? Can normal people buy one of these for a reasonable price, or is it only for workshops and cost big $$$? Will a normal OBD2 scanner be able to at least read the VM’s ECU and provide live info (coolant temps etc)?

From your questions it sounds like you are not a good candidate for a diesel. I have driven/ owned diesel cars/trucks/tractors etc for over 30 years. they are quite different to petrol cars. Your questions present as some one who doesnt have the type of driving style suited to a diesel.

You may be right in your assumption. I do like a certain level of ‘performance’ in my vehicles and enjoy driving them accordingly, but I’m not buying my next XJ for that. I want a decent off roader that can get my wife and I to most places be it just outside the city or 1,000’s of kms away comfortably with the least amount of hassle and fuel usage as possible.

Treated as a diesel, the VM is fine. if you expect them to behave like a petrol car, you will be disappointed as they dont. They are not a street racer but are a solid work horse.

What do you mean by driving style or, treated as a diesel, the VM is fine? I understand that diesels generally don’t rev like a petrol and its best to keep them in their torque band which is in most cases below 2,500rpm, is that what you’re referring to? The work horse side of things is what is attractive to me. Although I have never owned a diesel before I have a little experience with them as I've have driven them for work (small trucks and big vans -Iveco's etc) plus also driven my mates 4wd’s and help them work and service their 4wds here and there (Toyota’s) however am aware from the sticky’s that the VM is ‘different’ to the normal Toyo engines…

Like any diesel they do not take well to abuse or poor maintenance.
The engine in the TD is used in tractors stationary applications & boats as well as other cars. If looked after, not like a petrol, it is very reliable.

Poor maintenance I can understand, but what else do you mean by ‘abuse’?


Sorry if these all seem like totally dumb Q’s, I understand that the VM is a ‘delicate engine’ for the average owner, so I’m just trying to understand as best I can what they’re like to live with before I set out to buy one. From everything I’ve read, when they’re running great, then they are a sweet engine and hard to beat, that’s what I’m aiming for.

[layback40]

Thanks for all the info so far :)

I understand that the VM requires religious maintenance and I’m not saying I know all about it cos I would have a steep learning curve but I am in the habit of servicing all my vehicles every 5,000km and making sure everything is working as it should, if not better.

Whether I’m willing to take the plunge on a VM yet, which from what I understand has no fudge factor like the 4.0L has, is what I’m trying to decide as a trade off for fuel economy, manual trans, and good pulling power (torque) (which the 4.0L has but loses a little due to the auto trans).







Is this the ‘DRB2’ scanner? Can normal people buy one of these for a reasonable price, or is it only for workshops and cost big $$$? Will a normal OBD2 scanner be able to at least read the VM’s ECU and provide live info (coolant temps etc)?



You may be right in your assumption. I do like a certain level of ‘performance’ in my vehicles and enjoy driving them accordingly, but I’m not buying my next XJ for that. I want a decent off roader that can get my wife and I to most places be it just outside the city or 1,000’s of kms away comfortably with the least amount of hassle and fuel usage as possible.
When you get a second hand one, chances are the damage is already done. I use mine as a daily drive as well but it seldom gets a run less than 25km. Diesels dont like short trips. They need to be run for extended periods of time hence why they are good in trucks that do long runs. You dont attack a hill with it screaming like you may with a petrol.
As the VM 2.5 has separate alloy heads, the cooling system is critical. Just like the Mercedes om 602/3/6, if it gets hot, chances are you have already done damage. Clean coolant is critical. Clean fuel is critical. I do 10,000km oil changes as it does mainly long trips. If it starts to go wrong & you keep going it will go bang in a big way.
OBD2 is useless with the VM. The DBR2 is over $1k if you can find one. In the past 2 years I have not needed to get codes read.
On Mercedes diesel forums at times there are young guys wanting to turn up their turbo boost & get the most out of an old diesel Mercedes. They then wonder why they go bang. The VM has reasonably high boost when it is working hard. Its already been tricked up well before it went in the jeep. Running at max boost for long periods risks melting pistons. I have a boost gauge installed, it helps to get the best fuel economy as well, I have an exhaust gas temp gauge to go in some time.


What do you mean by driving style or, treated as a diesel, the VM is fine? I understand that diesels generally don’t rev like a petrol and its best to keep them in their torque band which is in most cases below 2,500rpm, is that what you’re referring to? The work horse side of things is what is attractive to me. Although I have never owned a diesel before I have a little experience with them as I've have driven them for work (small trucks and big vans -Iveco's etc) plus also driven my mates 4wd’s and help them work and service their 4wds here and there (Toyota’s) however am aware from the sticky’s that the VM is ‘different’ to the normal Toyo engines…
A person who drives a diesel all the time doesnt normally worry about turbo lag, they have adjusted their driving style around it. Many new little diesels are now designed to perform like a petrol engine. The VM 2.5 is more like a tractor engine. If you are a boy racer who likes to be first off at the lights every time using the engine performance to the max then a diesel is not for you.



Poor maintenance I can understand, but what else do you mean by ‘abuse’?

Drive till it stops. With a petrol you can let it cool down & it will go again, not so with a diesel.

Sorry if these all seem like totally dumb Q’s, I understand that the VM is a ‘delicate engine’ for the average owner, so I’m just trying to understand as best I can what they’re like to live with before I set out to buy one. From everything I’ve read, when they’re running great, then they are a sweet engine and hard to beat, that’s what I’m aiming for.
For an average Joe, the VM is a bit delicate, for a person who has been driving diesels for a long time its just another one.

[cheezel]

I have a 99 diesel. It still has some quirks/problems (can read my threads) but as I usually only get to drive it once a fortnight it has not caused me any great issues :-)

I am very much learning about the vehicle as I go along and must say that these forums are great, there is a wealth of experience and knowledge that people are willing to share.

No idea what you are looking at but for a '99 TD sport with "full" service history and 137k on the clock I paid $7500 for it but had to do a bit of work (new windscreen, new rotors & rear master cylinders, broken handbrake & clock spring, 3 new tyres etc -- general maintenance type stuff which I did except the windscreen & tyres cost about another $800).

I looked for a long time for a XJ diesel before I found one I wanted.

Cheers!

[murray]

i have one and the wife had a petrol you realy cant compare them as one is a auto the other is a manual
i wouldnt change it for the world it holds its own when 4x4ing
i am in perth as well if you want to check out what they go like

[Turismo07]

Thanks all for your replies, and to Murray for the offer, but i ended up buying a WJ v8...

Wasn't planning to, was always set on another XJ due to my budget but got it cheaper than most XJ's (update models) are for sale at the moment, it needs some fixing up, but I knew I was going to have to do that with whatever I bought anyway. Now I have more comfort, more power/torque, same offroad capability (in stockish form), and slightly better fuel economy than a 4.0L XJ (when driven nicely).

[Antiferret]

should have bought the wj crd :cool:
ha ha ha ha ha