A few weeks ago it got down into the negative teens and I knew neither engine would start, apartment rules do not allow extension cords across sidewalks so a block heater was not an option. I had no choice but to idle overnight during work and until the next afternoon. In total about 18 hours.

MPG on the previous fill of winterized diesel was 25.82mpg. This tank returned 19.53mpg.

No real point to this thread. I just thought I'd share a bit of interesting info and remind everyone that its okay to idle for long periods when necessary.

The only thing I have read is that the idle should be incresed to allow the EGT to be at least 350 so that the fuel does not end up washing the oil off of the cylinder walls due to not completely burning. Ford had a Fast Idle switch that allowed that - might be different for IDI.

Some times you do what you have to do. at least you start out with some heat for the cabin. Did you leave the heater on to keep the windows deiced?

I have often thought about using a Honda Inverter 1000W generator for a block and oil pan heater. would have to make it secure form sticky fingers to keep it from walking away.
block heater is 400W and pan heater is about 250W. the Honda puts out about 8 - 900W continuous, so should work. think the fuel would last 4-5 hours.

Could add a reciever hitch with a plate welded on, bolt on a tool box of some sort, mount the Honda in it with ventilation. they are quiet, almost can`t hear them run.

Living in an apartment, HOA, condo`s, Town houses suck. Too many rules. guess I have been blessed the past 23yrs, living in this old shack up on the hill, away from nosey neighbors.

Charlie

This is my first post here but I want to say something about the long idling of an old Mercedes-Benz diesel engine.

When the W123 model came out, a lot of them were taxi's here in The Netherlands, and taxi's often idle a lot here… the problem with that is, when you're engine is idling at operating temperature, the oil pressure is not at max (3+ bar) value, and so the timing chain tensioner does not tension the chain in an optimal way, that causes to wear out the chain quicker than when you'd just idle for short periods of time.

But I believe it's not a problem when you let the engine idle for a long time let's say… 5 times a year.

(01-25-2010 03:09 PM)sgtpeppers Wrote:  the oil pressure is not at max (3+ bar) value, and so the timing chain tensioner does not tension the chain in an optimal way

Thats not much of an issue, the tensioner ratchets out to keep tension even if there is no pressure.

Depends on the tensioner I believe, the story I heard about the taxi's (from a Dutch W123-club member) is that the chains wore out much faster because of the long idling n combination with the lower oil pressure. I'm not shure if that's on early models, in Europe W123's we're built from 1976, and through the years Mercedes-Benz made some small modifications to the engines.
And also, the chain tensioners do wear, and when you're engine oil is too thin, the oil will 'leave' the tensioner too quickly what causes the pressure on the chain to vary.

If I meet the club member again i'll ask him for the story again, and write it down here exactly as he says.

FYI The chain tensioner circlip that performs the "ratcheting" also wears out, mine did not too long ago in the wagon. On cold starts you would hear the chain rubbing/dragging until oil pressure would build up. Something to watch out for, I have seen one fail completely and cause the chain to jump on startup (big mess).

(01-24-2010 11:22 AM)Rudolf_Diesel Wrote:  The only thing I have read is that the idle should be incresed to allow the EGT to be at least 350 so that the fuel does not end up washing the oil off of the cylinder walls due to not completely burning. Ford had a Fast Idle switch that allowed that - might be different for IDI.

This is exactly right. In addition, the low combustion temps cause soot and unburned fuel to acccumulate on the back side of the exhaust valves.

I look at things like burning vegetable oil and long idle periods as being comparable to someone who smokes cigarettes or regularly lays out in the sun.

Many people burn VO in their cars or let them idle frequently and the engines seem to last a good long time. Likewise, many people smoke regularly or maintain a tan and also live a good long time.

Conversely, there are well documented problems associated with all of these activities. The severity of which varies widely depending on the lifestyle or the driving habits of the vehicle owner.

In the end, just because you can't percieve damage being done, it doesn't mean it's not happening and I can't imagine anyone saying that engaging in these activities is actually a good thing. Like most things in life, moderation is key.

to add to the list of anecdotes, I recently read a post from a candian mercedes owner that his neighbor would keep the 300D on for 6 months through winter. wouldn't even turn it off to fill the tank.

On the other hand, with effort and $$ you can install a webasto inline heater that will kick in with a timer and warm the coolant up for you at the proper time every morning.
I had a petrol version on my G that I removed when converting to diesel. I might re-jet it for diesel and re-install.

Wow, 6 months, that's a long time, can't be really good for the engine.

Installing a Webasto / Eberspacher / other brand pre-heater is not that hard, a W115 200D owner I know is going to fit a Webasto petrol one, with a small seperate tank in the trunk. There are even pre-heaters available that warm up the coolant, oil and interior, very nice in cold winters.