Diesel engines in winter

[RonK]

I note too that idling to warm up the engine is a waste of time too. I read that you should wait 60 sec to get fluids moving but because diesels run cooler no point waiting any longer. Just drive easy for a while (less than 3000 revs)

Warming up engines harks back to your grandfathers' day, before the advent of multi-grade engine oils. It's not necessary or even advisable to wait for the modern engine to warm. It will reach operating temp far quicker while driving.

[Gadgetgeek]

RonK, That's true, I guess I don't think anything is really cold until -20. One thought on that though, if you do a lot of short trips where the engine doesn't get to normal temp, its is good to idle it to warm it up to there periodically, as without warming, the condensation build-up can cause other problems. I've only seen it twice, once on a car owned by a guy who lived .5km from his work, so the car never warmed up (and never got above second) and the other was a propane ute I owned that had about half an acre of radiator, and ran cold enough to sludge all the oil with water (LPG creates much more water when burned than other fuels) Sadly that ute died of the congestion. So its rare, and I doubt anyone would run into it, but if anyone is pulling info from a north american, or european source, that might come up, and that's why.

[RonK]

It's never a good thing. Prolonged idling causes glazing of the cylinder bores leading to excessive oil consumption.
A short drive is much better - at typical engine loads there will be enough back pressure behind the rings to avoid glazing.
Personally can't understand why anyone would drive 500m to work.

[ErichFromm]

Thanks again for the responses. Seriously appreciate the assist.

Thanks too for the link to the PDF - great info.

[RonK]

Thanks again for the responses. Seriously appreciate the assist.

Thanks too for the link to the PDF - great info.

A final piece of advice - dirty air filters are the most common cause of diesel engine failures. Dust and subsequent wear in a diesel engines leads to loss of compression causing hard starting, poor performance and excessive oil consumption. If you are fastidious about anything, make it your air filter.

[Moondog55]

Don't all diesels come with a "Fast idle" setting ?
I know every diesel I've ever driven had one , to avoid the glazing effect of that slow revving. Usually between 1200 and 1500 RPM
Good advice on the air filter, reminds me that the ute needs a service

[GPSGuided]

No.

[stry]

Don't all diesels come with a "Fast idle" setting ?
I know every diesel I've ever driven had one , to avoid the glazing effect of that slow revving. Usually between 1200 and 1500 RPM
Good advice on the air filter, reminds me that the ute needs a service

Speeding up the idle won't help as the glazing comes from lack of pressure pushing the rings out against the cylinder walls. The pressure come from loading the engine up.

Can be an issue, albeit not as great, with petrol engines also.

[walkon]

Warming up an engine for a little while will not glaze it up. Yeah the oils have improved but it's also about warming up the pistons, block etc the tolerances close up as the motor gets hotter. Most engine wear is on a cold motor so you are dreaming if you think just turning the key and driving off is better than warming up the motor first. As someone who has owned numerous diesels in cars, trucks and machinery glazing up is a minute problem, poor maintenance is a far bigger issue. All my diesels are warmed up properly before they are driven away and in millions of kilometers plus many hours of operation on the machinery I've never had any issues with glazing. To be honest this issue on glazing is usually brought up by the lazy employees or the other tight operators who think not running the engine for a few minutes with save them dollars.

In regards to the fuel additive. It's simple, just put it in! It doesn't cost much and is a cheap preventative. I put it in on the way up and have never had any issues. Seen plenty of others have problems by not doing it though.

[Scottyk]

Warming up an engine for a little while will not glaze it up. Yeah the oils have improved but it's also about warming up the pistons, block etc the tolerances close up as the motor gets hotter. Most engine wear is on a cold motor so you are dreaming if you think just turning the key and driving off is better than warming up the motor first. As someone who has owned numerous diesels in cars, trucks and machinery glazing up is a minute problem, poor maintenance is a far bigger issue. All my diesels are warmed up properly before they are driven away and in millions of kilometers plus many hours of operation on the machinery I've never had any issues with glazing. To be honest this issue on glazing is usually brought up by the lazy employees or the other tight operators who think not running the engine for a few minutes with save them dollars.

Warming an engine will not glaze it up, I agree with that. You need to run at low load levels for an extended time for that to occur. What the danger of of the "driveway warm up" is it actually adds more wear to your engine in the long run as it takes so long for an an engine to get to running temp if its just idling.
You should start your engine, give it a few seconds for oil pressure to arrive at all the points in the engine then drive away slowly, that's it. Don't drive it hard until it is at operating temp.
This idea of letting in run for a period before driving away is at best a waste of fuel and at worst is damaging your engine due to the increased cold running time.
This is why multi grade engine oils are used.

[RonK]

^ Quite so. During a twenty year career as a Toyota technician and warranty manager I saw the results of the misuse and abuse of literally 100's of vehicles, and learned a few things from the experience.

[Travis22]

I didnt think glazing was a huge issue any more?

Ron, in your experience how would you rate say allowing a modern diesel - ie. D4D Prado or Landcruiser sitting at idle for 30minutes charging a heavily discharged auxiliary battery? Do you think any effects of glazing would appear if the above is done infrequently?

Id assume that to do the sort of damage you refer it would come from someone who lets their vehicle sit idle for an hour or more every day of its life?

Travis.

[RonK]

I don't think doing this occasionally would cause much damage. If it's repeated and prolonged then glazing is possible, but I wouldn't want to put a time to it.
For my own vehicles, petrol or diesel it's something I avoid. Start the engine, fasten seatbelt, release parking brake, check mirrors and drive off. That's plenty of warmup time.

[Moondog55]

And yet there are many modern diesels out there that spend a lot of their working time idling, our local bus line has a very modern fleet but they never seem to turn off the engine even when waiting 10- 20 minutes or so to catch up on the timetable. When I was doing my driving instruction for my HC license I was specifically told to leave the engine idling and certainly we never turned off the CFA trucks when training; although that may have been to get the engine oil hot enough to drive out the water and to charge up the extra batteries. A big alternator can put a reasonable load on an engine