Moose:
so from the points made in this thread we can conclude that most employed drivers on here would drive a fully loaded truck up say “birdlip hill” and then switch the engine off at the top without allowing any time for cooling
and most owners/ operators would after doing the same allow time for cooling before switching the engine off!
I don’t see that the reasons for running the engine a little have changed, after all it’s not just the turbo after a hard pull the engine may well be right at the top of it’s operating range temp wise and a few min’s of idle will allow the thing to cool with the coolant circulating, in fact with modern engines running at a higher temp and the fact that when a turbo does fail it can now cause many expensive problems that would not apply on a pre euro4 vehicle or older due to the lack of sensors, dpf filters etc
I do the same, and for the same reasons. And if I’m wrong, what does it cost me? A couple of pence worth of diesel.
This appears to be the most sensible post on this matter. Of course you let the turbo reduce speed by idling for a few minutes before you shutdown. Regardless of how good modern synthetic oils are, you need to keep the oil flowing through the bearings until the rotor slows down to idling speed. Its just the same as letting the engine idle after a hard climb, it gives the coolant some time to cool down the engine. I only once had a boiler in England and that was at the top of a long climb on a hot day to somewhere in the Forest of Dean, Cinderford, I think it was. It was with a BRS Bristol with a Leyland 680 in it loaded with bricks. When I pulled onto the building site, I switched it off and heard this awful noise, It was the sound of boiling water and was it boiling its guts out! so I jumped in and fired it up quickly to cool it down. I once had Foden with a 150 in it boil on a flat road at nearly maximum revs in WA just because I had a tail wind. Mind you, the wind was coming off the desert and it was nearly 50 degrees. Without air con, it was quite warm in the cab.
newmercman:
I always let the engine run for a few minutes before turning the key either way.
After pulling a hill or sitting in traffic I would leave it running a little longer to allow the hot spots to cool so the heat is spread evenly over the engine.
From cold, start it, let it run a couple of mins on tick over, then crank it up a few hundred rpms for a couple more minutes, then pull off slowly using minimal throttle and boost until it’s at operating temperature.
For that reason I never park at the bottom of a big hill.
What “bearings” are in a turbo charger?There are no bearings.any “bearing” exposed to +1000 degrees C and rotation speeds of 100,000 rpm would rip itself apart in less than a second.The oil is the bearing in a turbo,its forced between two bushings and holds the 2 faces apart.
Most turbo failures are caused by low oil pressure(pump failure or worn main bearings)contaminated oil (coolant in the oil etc) or the bushing seals failing and the oil is blown out of the central housing into the exhaust or intercooler.If the oil film is lost and the faces touch the turbine spindle just rips itself to pieces.
Guy across the street from me had a blinged up Subaru with a turbo timer fitted, seemed to let the car idle for about 1m after he had locked it and walked away before switching off. The fact these things exist would suggest its good practice.
Chas:
Perhaps it would be a good idea for someone to create a DCPC module on engineering appreciation & mechanical sympathy. They could call it “How a Truck Works”.
Whether your tongue was in your cheek at the time of writing, or not, I would actually find that more use than the current guff on offer
I’m deadly serious M8.
Unless half the folk on here are just out for a troll, it would appear that quite a few of us have little or no appreciation of mechanical sympathy & how operating a big diesel unsympathetically can massively increase the total cost of ownership.
I remember an ex boss chasing after a new starter in his car, he’d been slipping the clutch while shunting out of the yard in a fully loaded 8 wheel tipper & the ‘cork’ smell was overpowering as he drove past the boss’s window.
NB12:
Guy across the street from me had a blinged up Subaru with a turbo timer fitted, seemed to let the car idle for about 1m after he had locked it and walked away before switching off. The fact these things exist would suggest its good practice.
Good practice maybe for something in a ‘monster’ state of tune.
But turbos are now an integral part of truck engine design. Typically now a turbo will last at least half the life of the engine…pre Euro 3 you might expect to put 3 or 4 turbos on in the first life of an engine.
Unless half the folk on here are just out for a troll, it would appear that quite a few of us have little or no appreciation of mechanical sympathy & how operating a big diesel unsympathetically can massively increase the total cost of ownership.
I agree, and I also agree with the earlier poster who said that manufacturers are only interested in the interests of the original purchaser. All the manufacturer cares about is that the turbo lasts for 500,000 km, and boasting about the fuel consumption figures, neither the manufacturer or the first owner cares whether the turbo lasts for 600,000 km or 1,000,000 km, whereas I of course do.
If I pull up, leave the engine running and go to the back of the cab, there’s an enormous amount of heat being pushed out by the radiator fan. After a minute or so,the temperature of this has dropped noticeably and so it’s reasonable to assume that the engine is nearer ambient temperature than when I stopped. It’s also reasonable to assume that temperatures will have equalised to a degree among engine parts and so contraction rates will less different leading to fewer stress problems.
I may be wrong, but if it costs me an egg-cup full of diesel to do this each time, then I’m quite happy to pay for that in order to do what I think is best for my engine.
NB12:
Guy across the street from me had a blinged up Subaru with a turbo timer fitted, seemed to let the car idle for about 1m after he had locked it and walked away before switching off. The fact these things exist would suggest its good practice.
Good practice maybe for something in a ‘monster’ state of tune.
But turbos are now an integral part of truck engine design. Typically now a turbo will last at least half the life of the engine…pre Euro 3 you might expect to put 3 or 4 turbos on in the first life of an engine.
This must be why I never put a spanner near a turbo these days.
Where’s this data from, let me guess, manufacturers.
Never heard of a turbo being needed for a 14 litre ■■■■■■■ before Euro crap was even a ■■■■■■■■■ for an apparatchik, they always lasted the life of the engines where i worked, mind you the oils got chenged before they turned solid and needed to be dug out maybe that helped a bit…
I suppose if these makers desperately want to sell you a repeat order @ 5 years they’re not likely to approve of practices that makes it last 10…tell the mug what they want to hear, no different from politicians.
Moose:
so from the points made in this thread we can conclude that most employed drivers on here would drive a fully loaded truck up say “birdlip hill” and then switch the engine off at the top without allowing any time for cooling
and most owners/ operators would after doing the same allow time for cooling before switching the engine off!
I don’t see that the reasons for running the engine a little have changed, after all it’s not just the turbo after a hard pull the engine may well be right at the top of it’s operating range temp wise and a few min’s of idle will allow the thing to cool with the coolant circulating, in fact with modern engines running at a higher temp and the fact that when a turbo does fail it can now cause many expensive problems that would not apply on a pre euro4 vehicle or older due to the lack of sensors, dpf filters etc
can anyone tell me where I can buy some of this modern lubrication that hangs in the engine rather than the sump and how long on average it will take to drain the oil after removing the sump bung?
I don’t think that’s what been said at all, there is a great deal of difference between stopping an engine straight after its been working flat out and slowly pulling into a premises and coming to a gentle halt. The same goes from cold, pulling out of a premises gently and gradually building up the revs is a not the same as going flat out from cold.
well after a quick look back through this tread words like “totally pointless, and don’t see the point, no need these days, along with switch off wherever I am” jump out or are these folk now going to backtrack and start to say not if it’s been working hard?
so I would not agree, it is what was said!
Well said, Moose. I got my start as a long distance lorry driver in 1963 with Welch’s Transport of Henlow and finished up on BRS until I came to Western Australia 48 years ago. Some of the old ways I learnt in England such as letting the engine cool down before shutting it down are still relevant. Even going down hill in the same gear you went up in, one day you might experience a brake failure regardless of exhaust brakes and Jacob’s brakes ( there is a difference between them, you know) When I got promoted to a transport manager, there were certain things I expected from my drivers. Let the engine cool down before shutting it off and letting it idle long enough to let the turbo slow down. In my yard, these were sacking offences along with planting the foot on a cold truck to build the air up quickly and driving an artic into a tight spot or parking bay instead of reversing in. My motto was ‘If you don’t like it, ■■■■■■ it’.
Moose:
well after a quick look back through this tread words like “totally pointless, and don’t see the point, no need these days, along with switch off wherever I am” jump out or are these folk now going to backtrack and start to say not if it’s been working hard?
so I would not agree, it is what was said!
