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nissan
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Discussion Starter · #1 ·
Just a couple of quick questions for you 4.2 diesel owners.
1) Whilst the engine is still warming up after first getting it started, what rev range do you usually change gear?
2) When the engine has warmed up what revs do you usually change gear?

The reason for asking is i have noticed that yellow bar around the 1800-2800rpm (i think)on the gauge and when reving to around say the middle of the bar it sounds like i am almost thrashing it. I know that it is a big old motor that isn't really sound proofed and all that, so it isn't ever going to be that quiet, but just want to make sure that i am not killing it slowly, as i don't want to labour the engine either. So yeah thanks if anyone can shed some light.
 

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1) Can't help you there as I always let my engine warm up before I drive it.

2) Usually change gears at around 2600-2800rpm as that seems to work best for me. Change much earlier than that and its revving too low in the next gear. Any more and your not really gaining anything. Just my experience.

Thatss with 33's, 2½" exhaust and extractors with standard 3.9 diffs(as far as i know)
 

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Usually 5-10 mins. By that time the needle has started moving up the temp gauge. Lately temp gauge is not working properly but still let it warm up for the same amount of time.
 

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Warm up what's that?
I've had my TD42 shorty for 20 years hop in start up and go
I take it to 4000 RPM every day in 1st & 2nd not all the time though
Never missed a beat
Never been apart
Never had the tappets done
Been turbo-ed & w2a intercooled for 12 months now still drive it the same
I do let it cool down to 150 C before i turn it off now
It had 33000 km's on it when i got it
Now has 230000 km's on it just run in
I do live in the Tropics so it only gets cold 7 days out of 365
Run 33" tyres 4.11 gears
It's fully loaded steel winch bar,winch,alloy roof rack,140 ltr tank,roller drawers(full) cargo barrier, engel fridge,dual batteries
You can't kill them i've tried
 

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Learned the hard way - RD28t out TD42 in
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Sitting letting the motor warm up before driving off is a very bad practice. Ideal if you want to coke it up I suppose LOL.
 

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1992 (GQ) Nissan Patrol Ti Wagon
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The first couple of gear changes around the back street i do around 1800 - 2200 then after that anywhere up to 2800rpm, unless offroad, towing etc.
 

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I hardly ever rev mine over 2200, dosen't seem to pull much after that (and yes it does 2500 @ 100)
 

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Warm up ummm that would be the time it takes to lock shed door
gear changes between 3-4000rpm, runs 32's 2.5inch exhaust with genie extractors
use to change gear between 2-3000rpm just use to get sluggish and coke up engine, give it a good flogging and runs great minimal smoke been doing that for last 100k and haven't done anything to engine apart from regular servicing, bit like 91Shorty
 

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Wait til oil pressure light goes out, back out of man land(garage) wait for door to
close and thats it.
Mines turboed so i drive on about 1/4 to 1/2 throttle everywhere and just
rev it in the yellow area or there abouts.
Yes they like to be used.

Cheers Ian.
 

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Sitting letting the motor warm up before driving off is a very bad practice. Ideal if you want to coke it up I suppose LOL.
Why do you say that? Been doing that for 60,000km's I've had it and no problems. Took the rocker cover off and no build up in there at all.

But if it's really not good for it then I'll have to change that
 

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GQ Dual Cab. TD42Ti with fruit.
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Why do you say that? Been doing that for 60,000km's I've had it and no problems. Took the rocker cover off and no build up in there at all.

But if it's really not good for it then I'll have to change that
Majority of engine wear is with a cold engine. Therefore it is advisable to minimise the cold running time as much as possible. Gentle driving will raise the operating temp much quicker than sitting in the driveway, therefore reducing engine wear.
 

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if you idle a old style diesel for long periods it doesnt burn all the fuel thats going into it and glazes the bores.

im actuelly starting to get worried about my engine,iv been working on the car for a while now and i only start it up to move it. and i also let it idle for long periods while im sorting out problems,wonder if im doing it harm
 

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Discussion Starter · #14 ·
Right well thanks for all the diffent replys. Lots of different responses but it all suggests that i am not thrashing it like i thought i was lol. Thanks for putting my mind at ease.
 

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I don't rev to a particular rpm, I change when its required or rev it till It feels right for the next gear. I do however keep it below 2800ish when cold.

I don't think sitting warming up is going to do any harm unless its hours on end, Iv'e never seen an engine die from over idleing. Just use it how you want and stop worrying
 

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i start wait about 30seconds max, then drive out of my complex. cruise down to the lights bout 300m.
cruise again to round about 500 or so metres. then its basically what ever is needed to get up the hill other side of round about. but do try and just cruise when cold. when its hot a very different story. i change when needed. and if it needs 4000rpm to forfill requirements then it gets reved to 4k. diesels dont like being chugged around and need a good rev to clean em out. mine always run better after a good thrashing on the highway for a coupe of hours.
 

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1: drive it nice and gentle for a bit, keep an eye om my temp gauge in the upper hose, when that starts to rise above 50 I know the thermostat is open.
2: depends which turbo is on it and how much of a hurry I'm in...
2A: One I change at 3200 if I'm hauling something heavy standard DTS TD05),
2B: the other depending on the situation I change at 2000 to keep it docile and polite if I need to, or if I'm giving it some I will change at 3900 (modified and high-flowed TD05).
 

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Yet another debatable subject.
Mr Emanuel states:
1 to 2 _ 25km/h
2 to 3 _ 40 "
3 to 4 _ 65 "
4 to 5 _ 75 "

Of course all this depends on how different your truck is from OM, so adjust accordingly. For instance, riding on 32"'s I seem to hit 5th about 80 km/h, (with an AM turbo these parameters have changed again) but like others, it's just instinctive, when to change. Also you have to take into account the terrain (and load), if your going up a hill the km/h and revs would be higher.
Fortunately I live on a hill and use low revs down the track to the grid, so my secondary warming up period is nicely taken care of (at home).

As for the more debatable initial starting and warming up, old Emanuel states:
"Adjust the throttle control Knob until the engine runs smoothly.
After the engine has warmed up, turn the throttle control" off... na na na.
So make of this what you will, as I have had a gut-full of debating the obvious.

Must add though, modern diesel engines have all sorts of (complicated) gizmos to overcome a warming up period, and basically drive straight off, (snigger... maybe another reason for their earlier demise) the engine we are discussing here however is circa 1986.
At idle they use a minuscule amount of fuel and a lot of air by ratio. Oil is changed at 5000km for more than one reason, etc etc etc ad nauseum.

Patrolvic, nice to hear from someone WGAF.
 

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Crikey sounds like I'm driving like a nana and changing too early compared to you blokes!

I change gears between 2000-2200 RPM on my TD42 with 33's. Take it up to 2400 sometimes but rarely.

Never had it at or over 2800 - thought that would be over revving it.
 

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I dont understand the mechanics of it, but i read on another forum that its practically impossible to over rev one of these engines as, the pump has a built in mechanism to prevent this from happening.
 
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