trucks idling

medic417 said:
Actually if you read the manuals on newer diesels you will find they are not designed for extended idling.
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High Idle. any diesel new or old, they actually over heat if not running at a high enough RPM. 900-1100 rpm is what we are thought is the safe range for a diesel engine.

on a side note has anyone worked in a gas amblam. i got the pleasure the other week and let me tell you they are the bees knees. smooth, quiet, QUICK AND FAST. we wont know about the durability for a year or two but for now they are getting rave reviews. the ford V10 is the way to go right now.
 
socalmedic said:
High Idle. any diesel new or old, they actually over heat if not running at a high enough RPM. 900-1100 rpm is what we are thought is the safe range for a diesel engine.

on a side note has anyone worked in a gas amblam. i got the pleasure the other week and let me tell you they are the bees knees. smooth, quiet, QUICK AND FAST. we wont know about the durability for a year or two but for now they are getting rave reviews. the ford V10 is the way to go right now.
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Actually has to do with idling at any speed they clog up exhaust then you have to send them for repair. The 2011 models with exhaust fluid may not have as much trouble but that is yet to be seen.
 
High idle has nothing to do with overheating or clogged exhausts in a diesel engine.

When a diesel idles below 1200 rpms. They fuel will start stacking in the cylinders. This causes "washdown", which will basically wash the oil off the cylinder walls and destroy the engine. Most high idles are set from 1250-1500 rpm. The only time a diesel should idle normal is after a long hard run. This is to allow the turbo to cool down, before shutting it off. If you shut down a hot turbo, it will burn the oil on the bearings and bushings. This is called "coking" and will destroy a turbo fast.
 
reaper said:
High idle has nothing to do with overheating or clogged exhausts in a diesel engine.

When a diesel idles below 1200 rpms. They fuel will start stacking in the cylinders. This causes "washdown", which will basically wash the oil off the cylinder walls and destroy the engine. Most high idles are set from 1250-1500 rpm. The only time a diesel should idle normal is after a long hard run. This is to allow the turbo to cool down, before shutting it off. If you shut down a hot turbo, it will burn the oil on the bearings and bushings. This is called "coking" and will destroy a turbo fast.
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A diesel should also idle normal when the vehicle is stopped at a red light.

Does this "washdown" you mentioned also occur with modern electronic fuel delivery systems?
 
Yes, as you know a diesel needs heat for combustion. When it idles to long at low rpm, the cylinders lose heat and all the fuel does not burn. So it starts collecting on top of pistons. Then gets by the rings and washes the oil away from the walls.
 
reaper said:
Yes, as you know a diesel needs heat for combustion. When it idles to long at low rpm, the cylinders lose heat and all the fuel does not burn. So it starts collecting on top of pistons. Then gets by the rings and washes the oil away from the walls.
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Seems like this would be incredibly easy to manage electronically. For example, if the brain determines the engine is getting too cool, it can raise RPM just enough for for just long enough to get it warm enough. This way, the use of high idle can be minimized, thus minimizing the extra fuel consumption, extra pollution, extra wear and tear, and extra noise associated with it.
 
A lot of the big Detroits and cats do have this. Just hasn't hit the smaller ones. Costs more money
 
reaper said:
A lot of the big Detroits and cats do have this. Just hasn't hit the smaller ones. Costs more money
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It shouldn't be significant. It's just a bit of programming. The temperature sensors and means of controlling engine RPM are already there. But it's good to know it's being worked on, at least.
 
i know my engines engine hi idle in 1150rpm per the manufacture it is a Detroit 60 series 450hp. my ambulance hi idle set by ford is 950. 1500rpm would be screaming, that is higher than crusing speed.
 
I really wish my service told us things like "it will damage the trucks if you let them idle normally for hours at a time," because I had nooo idea before reading this thread and wouldn't have thought to look into it.
 
Aerin-Sol said:
I really wish my service told us things like "it will damage the trucks if you let them idle normally for hours at a time," because I had nooo idea before reading this thread and wouldn't have thought to look into it.
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It was something that I had to be told, too. We were always instructed to set the parking brake so the engine would "high idle" when we were posted, dropping a patient off, etc.

Just don't forget to release the brake before your next call, it's embarrassing when you're driving down the road and smoke is coming from the brakes. Trust me.
 
Wow you guys have it bad, the company i run with just built us a new station which is where we run out of unless on standby, Climate controlled bays, buses are always plugged in and ready to go. We don't ever have to bed anywhere but the station unless on a call.On standby though we try to keep our rigs relatively warm, but at most events its summer so its trying to keep it cool. BTW the 2010 fords are JUNK, we've had to many problems with ours before they even hit 40,000 miles. Oh and our E-brakes only work for high idle, they wont hold the rig in place
 
C.T.E.M.R. said:
our E-brakes only work for high idle, they wont hold the rig in place
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this is because someone drove with it on, or you need to adjust it. you may want to have the mechanic take a look at that...
 
I know in our region of NY we have to keep our vehicles running most of the time, be it hot or cold to keep our on-board drugs within certian temp. ranges.
 
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