Dreamed

Dreamed

Member
When do you guys change gears when driving a TD4 manual?

At the moment I'm changing around 3-3.5k revs, but it sounds as if I am forcing the engine and it might not be the best for its overall longevity.

I'm interested in prolonging cars' life as much as possible. So I'd like to make an educated choice when I change gears. My ears tell me 2.5k is the best to change gears, as the engine doesn't scream too much, but I've heard people saying diesels need higher revs to avoid clogging up the system.

I also suspect changing from 1st to 2nd should be done at different revs than changing from 2nd to 3rd... etc
 
Cruising around with a diesel is ok but every few hundred miles, it's generally considered a good idea to give it a hard drive, this will bring up your cylinder temperatures and exhaust temperatures to help burn off any deposits of soot and particulates.

Diesels like to be run hard (constant of around 80% peak power on diesel generators) and survive better if they are. Obviously, this is the opposite of what you want for economical running.

You are correct with the gearing, the freelander's lack of low gearbox was made up in some part with a low geared first. I have a petrol K series turbo engine in mine and generally pull away in second and only really use first gear around the farm.
 
monkfish24 said:
Cruising around with a diesel is ok but every few hundred miles, it's generally considered a good idea to give it a hard drive, this will bring up your cylinder temperatures and exhaust temperatures to help burn off any deposits of soot and particulates.

Diesels like to be run hard (constant of around 80% peak power on diesel generators) and survive better if they are. Obviously, this is the opposite of what you want for economical running.

You are correct with the gearing, the freelander's lack of low gearbox was made up in some part with a low geared first. I have a petrol K series turbo engine in mine and generally pull away in second and only really use first gear around the farm.
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Diesels like to be run at plenty of power, and it is an even better idea on modern engines with DPFs, they soot up if you drive around at low revs all the time.
 
normally change gear when noise gets too loud in first and so on. I prefer not to waste each gear as I stall at the lights in fifth to the chagrin of drivers behind. Hey if learners can do it why not I when i explain to the angry faces.
 
The TD4 gives best economy when you change up at about 2 - 2.5K RPM.

My automatic changes up at 2.5K RPM, unless I'm giving it some beans.
 
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Turboman said:
I don't know much about Freelanders, but that would suggest to me either that it is clearing out gunge from running at low revs beforehand, or that your injection system is overfuelling.
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I believe the induction system is clear of leaks, I did change 1 hose that had a split recently, but that didn't fix it - not sure leaks would cause the smoke anyway as the older EDC runs off a MAP rather than MAF for fueling. I regularly change air filters. Its direct injection, the VP37 pumps are pretty reliable and the injectors are simple nozzles that shouldn't over fuel - but may have a clogged spray pattern I suppose. It could be clearing gunge out as I don't take it over 3K revs very often or it could be the EGR letting exhaust through. I have cleaned the plenum out which had a fair amount of gunge in it, but never cleaned the EGR or inlet manifold - suppose I should do really as its 20 years old now, done almost 150k miles and probably never been done! (I've owned it 8 years).
 
GrumpyGel said:
I believe the induction system is clear of leaks, I did change 1 hose that had a split recently, but that didn't fix it - not sure leaks would cause the smoke anyway as the older EDC runs off a MAP rather than MAF for fueling. I regularly change air filters. Its direct injection, the VP37 pumps are pretty reliable and the injectors are simple nozzles that shouldn't over fuel - but may have a clogged spray pattern I suppose. It could be clearing gunge out as I don't take it over 3K revs very often or it could be the EGR letting exhaust through. I have cleaned the plenum out which had a fair amount of gunge in it, but never cleaned the EGR or inlet manifold - suppose I should do really as its 20 years old now, done almost 150k miles and probably never been done! (I've owned it 8 years).
Click to expand...

As far as I know, all injector nozzles can wear over time, and that will tend to cause overfuelling, or give the effect of overfuelling.

flat said:
Yep, basically, go hard or go home (on a recovery truck if you over Rev it )
Click to expand...

You shouldn't really be able to over rev a diesel, that is what the governor is for.
Doesn't always hold good on older and worn engines, though! :D
 
Turboman said:
As far as I know, all injector nozzles can wear over time, and that will tend to cause overfuelling, or give the effect of overfuelling.



You shouldn't really be able to over rev a diesel, that is what the governor is for.
Doesn't always hold good on older and worn engines, though! :D
Click to expand...

Especially if they start self revving in their own oil :eek:
 
pardec said:
:eek:
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Nothing to worry about, can be quite entertaining. When my mate's 2.5na ran away in Hayle, it completely filled Front Street with smoke, and stopped the traffic both ways! :D

The vehicle was stationary, no-one was hurt, it just totaled an engine that was on it's last legs anwyay.
 
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