There are several issues that develop from extended idling time .
1 The diesel engine unlike the gas engines only use enough fuel to keep spinning. Therefore creating very little heat at idle . This coupled with a high capacity cooling system will not allow the engine to maintain operating temps. Engine oil needs to be heated to keep vaporizing the moisture out of it that acumulates from the combustion process and will breakdown the addative package prematurly.

2 Before the advent of warm up devices there was also the issue of bent push rods from valve stem varnish . The valve stems would build up varnish from excessive idling in cold temperatures . Then would glue the valve stems in the guide . Upon the next startup the pushrods couldnt handle the load required to break the varnish free and bend . This was a big issue back in the 90's when the warmup devices were optional. Now they are standard on most light duty diesels.

3 Idling means low oil pressure . Low oil pressure is bad for bearings that rely on pressure to prevent metal to metal contact. Turbo's especially need high oil pressure to keep the impellars centered in the housing.

In general there are no benefits to idling more than a few minutes after coming off the the road. And really unless you are working the engine hard right up to where you are going to shut it off you can use it just like a gas engine and shut it off right away.

The comment about diesels running away by consuming engine oil is true but very rare. I have never seen it but have heard of it happening on Detroit 2stroke diesels when they would have a supercharger seal failure.

If your nieghbor thinks he needs to treat his pickup like a heavily loaded big rig then he is misinformed .

 

Thank You for the advice, thats a good one to ask him if he leaves his truck idle for hours when he drives it to work or when he stops for fuel, thats a good one, I never thought of that , ur right, good thinking, thanks again.

 

Tell him to get a Duramax... gas jobz are even louder than them..... lol

Anywho if im just idleing around town, i barely let my diesel idle after i put it in park. If im crusin down the hi-way ill let it idle for 5 - 10min.

 

I have been an owner opperator for fifteen years and have owned nothing but diesel pickups. Research has shown that for every hour of idle is equal to 50 miles of wear on the motor. Just think, the guy that lets it idle all day is almost due for an overhaul.

 

I know some farmers who use to let tractors idle when not in use.....never shut off! I suppose that has came to an end with the fuel costs now.... they also worked maybe 14 hour days or so

 

Yeah, we live next to some jerks too. They really stink.

 

I did ask him if he lets his Dodge diesel idle for hours when he drives it to work or if he leaves it idle when he stops to fuel it up? He said everybody leaves their engine run while getting fuel .He said any diesel will run hot and overheat if you shut it down after the engine warms up and leaving it idle will keep the engine cool down plus he did say his turbo has to cool down cause the heat will damage the seals and something about his engine oil pressure is at 2000 psi and leaving it idle will lower the oil pressure and the high oil pressure may cause a blown seal in the pump or something I don't understand.

 

Well, I'm starting to think that he's just nuts.

 

I will second that....

 

Wow.. Great thread guys! First off, I'm not a idler or not an extensive one anyway. I've owned a 96 F350 diesel for about six years now and it has been great to hear the responce for both the truckers and mechanics. This makes complete sense and common sense always seems to prevail.

How about this ole' one though.

"don't run a diesel on short trips (or frequent short) because it's hard on them."

"And if you do make a series quick trips, it best to let them idle if you can rather than turn them off."

I suppose it's more of an operating temp thing or makes no difference.... or does common sense prevail agian!