Re: Driving a Diesel - Best Practice?

Mate I am no mechanic, but I have learnt a thing or two.

When you look at the torque and power curves of a 2H you will see that torque peaks quite low at around 2000 rpm, but power peaks at around 3500 rpm.

When you are changing up and accelerating hard (ish) you want the engine to be delivering decent torque values when you let the clutch out, which will assist until the engine starts delivering more power as the revs climb. The gearbox on your engine is designed to do this, and if you change at around 3000 to 3200 on the way up, you will see that you should be around 1800-2000 in the next gear when you let the clutch out, which is in the sweet spot for the torque value. This is especially relevant when towing or climbing a hill. When changing down to climb a hill, change down at about 2000, as this will put you back on the power curve in the lower gear.

Dont let it labour in top gear. You will flog out the thrust bearings, big end bearings and cause other problems. depending on your driving style and acceleration requirements, I wouldnt select 5th until doing 80km/hr when accelerating. putting around below 80 in top gear is fine, just dont expect to accelerate.

another rule of thumb I have learnt from years of nursing high end engines: for longevity, dont operate over 75% of your rev range for long periods. I think from memory red line sits near 4000? therefor 3000 rpm would be a comfortable non problematic long term rpm.

Others will chime in year I am guessing, and possibly suggest otherwise, which is fine of course. Ultimately your driving style will dictate the many variables.

One other thing - when going up a hill, try backing off with the accelerator a smidge. keep backing off untill you hear a change in engine note. keep the throttle there, as any more throttle is only wasted fuel. You will be amazed at how much throttle movement is not necessary. diesels are quite different to petrols in this regard.

Have fun!

Re: Driving a Diesel - Best Practice?

G'day Jono, Cades got it right as far as operating your 2h, they are really a small truck engine and if you do as Cade says, you won't have much trouble.

Never put your car into neutral when going down a hill, your engine and gears are the best brakes you have, technically wheel brakes should only be used for emergencies and stopping. Driven properly you can reduce wear and fuel consumption by using your drive chain properly.

I'm one of those people who bring their vehicles to operating temps before driving off, engines being metal have expansion rates and tolerances built in so they give the best performance when at specific temperatures. If you drive your vehicle before it has reached operating temps, extra wear will start to occur. As we use SVO, it helps because as soon as its started I switch over and by the time it's ready to drive, the VO is at the right temp.

Same for shutting down the engine, I always let it idle for 2 minutes to allow oil flows and tolerances to adjust, instead of suddenly stopping and leaving very high temperatures and oil pressures. Most people forget when you shutdown a hot engine, internal temperatures rise initially, unless heat is dissipated, which happens with pre shutdown idling.

Re: Driving a Diesel - Best Practice?

Yes make sure you let it warm up - i try to run mine for at least a couple of minutes in the morning (until my temp gauge shows 40c for Water) to be kind to the engine.

Such an old motor it would be worthwhile doing an engine flush - everyone has their pet product/way of doing this - i use a product FOC - from http://www.costeffective.com.au/ and have done so on all my diesels.

I also add their ANtiWear product to the engine - about 20ml a month and the transmission - about 10ml per month - the engine sounds better when this added.

I personally swear by Bypass Engine Oil filters - again others seem to have varying opinions http://jackmasteroilfilters.com.au/ - i never change my engine oil with this - just once a month change the toilet roll filter and top the engine oil up - thus adding new detergents etc to the oil

Again depending on how your transmission has been treated you might want to get it flushed out also (is it manual or auto ?)

Craig

Re: Driving a Diesel - Best Practice?

Personally, I would be very hesitant to use any type of "flush" in an engine.
Is there any reason to believe you have a big build up of crud?
As long as the engine is running OK I would leave well enough alone.
If you run a flush in your engine oil and it starts breaking deposits loose you could end up with blocked oil passages and a damaged engine.

I normally start my car and drive away withing 15- 30 seconds of starting- even in the winter. No hard acceleration for a few blocks and I am good to go for the rest of the day. I use biodiesel so fuel viscosity is not a concern

Re: Driving a Diesel - Best Practice?

Not understanding this one sorry Tilly. The purpose of the flush is to break loose any and all crap and to get it out of the oil galleys in the engine. Based on your comments (i am inferring) - you seem to agree their could be crap in there - and if you break it free it could be bad - surely if you do not break it out and it comes out of its own free will at some point this could be far worse ?

The way i have always done it when i have purchased a new diesel is to run one of the flush products - as the manufacturers recommend - drain current oil, fill with sacrificial oil, add flush and run for 1/2 hour at fast idle - then drain again.

Whenever i have done this the oil that comes out is always very thick and full of sludge - so it is definitely carrying something out of the engine with it.

As an aside - even though people claim that bypass filters do not work - i have just done the same process above on my suburban - which is the first time in 3 years that it has had the oil dropped and the sacrificial oil came out looking like it was nearly new - still slightly black - but definitely no sludge or thickness to it.

Craig

Re: Driving a Diesel - Best Practice?

I think the real purpose of most engine flushes is to relieve people of money they do not need to spend.
There could be crud built up in your engine, you never know.
I do not know if there is or isn't any crud in my engine.
However, if there is crud built up, it is not causing any problems because my car is running fine. I sure have no intentions of trying to stir the crud up to get it moving in my oiling system. The last thing I want to do is "break lose" any crud that might be there and give it the chance of clogging oil lines and causing oil starvation damage to the engine.
I have never run any type of flush in any of my engines
I do not know why it would be far worse if it broke lose on it's own.

Don't fix it if it isn't broke


What manufacturers recommend this? Not the engine manufacturers I would guess.



You mean that after you drain the old oil and then fill it with "sacrificial" oil with flush added and run it for a half hour, when you then drain the hot sacrificial oil you find that it is now very thick and full of sludge?
It sounds pretty drastic.
Where are you getting your second hand diesels?
How many diesel engines have you done this with?

EDIT
You have not been buying cars from my brother in law have you?
He had a car just stop dead while going to work. Problem was linked to the fact that he bought the car new three years earlier and in that time had never changed the engine oil

Re: Driving a Diesel - Best Practice?

i'm a bit like tilly in regards to warm ups and additives, regular oil changes, and i replace the filter each time and normally fill it with oil before putting it on where i can.
i take easy for about 10 klms especially if i have a heavy load on to warm up the diff and gearbox.
cheers stuart

Re: Driving a Diesel - Best Practice?

Having a nice clean engine is not going to do any harm. One guy here flushes his 1HD-FTE with four litres of biodiesel and runs it at idle for a few minutes. He runs it on bio as fuel too, and being direct injection, his oil stays clean for thousands of kilometres after oil change, looks like honey.

IDI is always going to create more soot, more black oil, than a DI. But surely as long as you follow manufacturers oil change schedules and use oil within spec, then there's nothing particularly wrong with this approach, like Tilly.
Nor is there anything wrong with running a flush if that's what you like the idea of.

Tim

Re: Driving a Diesel - Best Practice?

Exactly.
There are endless products in the huge aftermarket auto industry that are completely and utterly useless. This is just another.
If you look at what is in them, it's all the same stuff which is available at Bunnings for $11 bux a litre I paid the other week.


It makes me wonder how many people have worked on engines or stopped to give a moments thought as to how the reality adds up to the fearmongering these products work on. An engine with regular oil changes of the right type of oil with a working thermostat and otherwise running and serviced as it should has no to very little "crud" build up. That's the first thing.

Secondly, engines that have some build up have it on non rotating parts. The only parts that can have build up of any possible concern are generally the drain gallerys not the supply galleries because once there is any restriction the oil pressure pushes it out.

3rdly, any engine that has blocked gallerys from lack of oil changes, no thermostat etc is already stuffed and has excessive wear that makes the build up from the lack of oil changes a moot point. The smallest galleries are the ones oiling the camshaft(s) so if they are fine, everything else will be. If they are not then the engine is definately a limited proposition anyway and a chemical can't clean where it can't get to, IE, an already blocked gallery.

Not last or least, ever TRIED removing sludge or buildup from an engine? Nothing short of mechanical scraping or intense chemical/ heat treatments will shift the stuff. I have never even heard of some of this stuff breaking away and clogging galleries. It usually just sits in places with adequate clearance and doesn't move or interfere with the engines operation. I fail to see the point of making the engines internals any cleaner than what regular oil changes afford anyway.

What I have seen repeatedly and was a problem on some cars is small, hard bits of carbon that eventually block the oil pickup screens.
If you have ever tried to clean one of these screens, you know how hard it is and that the fix even backyarders employ is to throw the thing to buggery and replace it with a new one because it's near impossible to remove the stuff without buggering the screen.
To imagine that some diluted additive is going to shift this stuff in 5 or 15 min while the engine is running and pulling it into the screen is a leap of faith from people I'd like to sell some shares in the Sydney Harbour bridge to.



Thats because you are a realist and a person that can think for themselves.

I don't know what people are so worried about "Breaking Loose" in the first place? Chunks of diamond hard carbon the size of gravel? Litres of tar like gloop that are going to wrap around the crank or pickup like plastic bags?
Forget about the hype, can someone tell me with logic and reality applied, exactly what is so terrible in their engine that's potentially going to "Break away" and cause so much catastrophic damage???
Any soft sludge that "Breaks away" is going to be picked up in the oil filter the same as any hard bits that make it through the filter screen. The oil goes through the filter before it goes to the bearings and cam so what's the difference about what's stuck on the non moving surfaces?


I'm wondering the same thing.
I hate to think what the rest of the vehicle must be like if the previous owners maintenance was so slack as to not change the oil regularly so as to cause this sludge proliferation in the first place.
The engine internal condition is real easy to check, just look under the oil filler cap. If it's clean, chances are the engine is. If there is buildup, the engine has no chance of being well maintained. If you can as on most engines, have a look at the rocker gear through the filler hole. . If it's clean and sludge free, the rest of the engine is. If it's full of crap, well then why in the hell would you buy a vehicle like that ??? If the engine oil wasn't changed, hate to think what the transmission and diff is going to be like not to mention the last time the coolant and brake fluid was changed!

Checking under the oil cap and the rocker gear through the filler hole is pretty basic stuff you do when buying a used car!


There are a number of rental cars companys now that do the same thing to save money on servicing. They only keep them a limited time so they top the oil up when needed but don't change it. Cars won't show the effects till they have got rid of them so what do they care? As long as it lowers their running cost, all good.

Re: Driving a Diesel - Best Practice?

Hi folks!
I am pretty new to this forum so I hope you do not mind if I add my thoughts to this discussion as a long time mechanic.

Peter1 has hit the nail on the head.
The only deposits an engines flush removes are the ones in your wallet.
I am always amazed at how brazen the sellers of this type of snake oil are. I am also disappointed that the government does not take a stand and eradicate this type of fraud.

I know of no engine manufacturer who recommends the use of an engine flush.
All you need to do is change your oil to the schedule in your owners manual and you will have no problems.

If you look at the MSDS to most motor flushes you will find they are usually made from a mixture of Kerosene, mineral turpentine and diesel fuel.

As far as draining your engine oil and filling it with biodiesel as a flush- this sounds like a really bad idea. I strongly advise against doing this.

Re: Driving a Diesel - Best Practice?

I'm nodding at what you say Tilly and Peter1. I have never used flushing products either. When I last checked my valve adjustment the rockers etc looked clean as new. I have seen far blacker under a petrol rocker cover. My engine has always had oil changed at the recommended 5000km. I am confident the last owner did the same as he was an older guy who looked after his vehicles. However I picked up a wreck with an unknown history and the oil is so tar like I am considering flushing that. I'm was thinking a mixture of the cheapest oil and biodiesel. Costra why do you think it is a bad idea? Kero and oil does sound fairly safe I must admit.
Bypass filters, I do have one but don't extend the oil change period. They worked better on a petrol car I had, the oil would look like new after 25000ks

Re: Driving a Diesel - Best Practice?

I was talking cars and mentioned this engine flush thing to a mate this morning who has spent a lot of time building BIG engines in earthmoving equipment and generators etc.
His comment I thought was a classic:

" Why would you want to flush an engine? Did someone take a dump in it???"


Another Veg world proclivity ( amongst other places) That makes me laugh is the obsession some people have with using the latest and greatest engine oils.
Particularly in the Veg world where the average vehicle has 10-20 years on it, You can buy the cheapest supermarket brand oil you can find and it's still about 5 specification grades ABOVE what the manufacturer specifies and exceedes what the engineers who built the engine probably even imagined.

To think that using expensive synthetic or other wonderful oil is going to give years extra life to an old design engine is like thinking you'll get more in a cup if you fill it from a bucket instead of a litre bottle.
A person would do far better for their engine by buying supermarket brand oil and changing it twice as often or whatever the savings allowed, than running some over spec oil to its recommended interval or beyond, especially if you are Running veg fuels.

Of course in doing that, you wouldn't even need to think about wasting your money on some bogus engine flush because every time you changed the oil you would peer into the rocker cover and see the nice shiny metal sitting in there and know it was clean and deposit free.

Re: Driving a Diesel - Best Practice?

There's no reason to flush new or rebuilt engines, but I flush our 2h and Isuzu engines each oil change, use 500ml of dino and 2 stroke, the Isuzu has done over 680000 and 2h 600000. Done that since we got them, don't bother about the 12ht rebuilt engines yet, but when they get over 200000 will probably do it as they are di and need extra care using SVO.

Why, simple they run on SVO, have done lots of klms, there is certain amount of blow by at that age and internal wear. Not worried by carbon build up, it's more to do with any mixing of SVO and engine oil. Always get a bit of sludge and as the IP is oiled from the engine I'd prefer it not to end up there.

The same with the fuel systems, always put some 2 stroke in the startup tank to help keep the injectors clean and every 5000klms run 2 lt through the fuel system, you feel the difference in the 2h, not sure about the Isuzu as just put a new turbo on and it has heaps more power. The 12ht seems no different, but both are newly rebuilt. One has done 5000 klms, the other less than 3000klms.

My father who was a racing driver, made me warm engines up and when driving road trains, you could really tell the difference between a cold drive off and a warm one. It's the same now, would never drive any of our vehicles before reaching operating temps, especially using SVO. But that's me, had it drilled into me the difference of an engines ability to produce its full power and the required expansion and built in tolerances of internal parts. It all makes sense to me, engines are designed to operate at certain temperature, so expansion tolerances are built for those specifically, not when cold. You never see a racing engine being driven under load until it's warmed up and they pre warm them before warm up laps. Same with all vehicles, until parts and lubricants are at their designated operating temperatures, you can easily get wear in new engines. Seen many truck engines over the years clapped out because drivers have idled them at 650-850 revs for long periods and short trips, when the engine either doesn't reach operating temp, or cools and you get wear and finally blow by.

Was always taught to start an engine at low idle speed and when oil pressure is reached, idle at 1200-1350 to bring the engine to operating temps. Idling below those revs, means your engine either doesn't reach operating temps before driving off, or whilst standing with a hot engine, it cools down to below operating tolerances. In either case you get wear and finally blow by.

Re: Driving a Diesel - Best Practice?

Obviously, everyone has their own opinion and I see no evidence of a shift in position from the proponents of each of the methods discussed. Without having specific test results for each engine discussed, for each of the methods described, there is no likelihood of anyone being convinced.

Please feel free to continue using your preferred routines, as you are comfortable with them.

What are my preferences?
1. Start and drive
2. Change engine oil at 1/2 manufacturer recommended distances
3. Change oil filter at each oil change
4. Only change fuel filter when it affects performance
5. Flush the toilet only!

I am enjoying the conversations.

Regards,
Tony