Engine/Transmission (1994 - 1998) Idling Cummins overnight in the Summer?

[SuncoastCustoms]

I have been reading around about Cummins and their dislike for idling, but I have also be noticing that the people that are talking about idling their Cummins are doing it generally up north in the cold of winter. I am going to be taking some trips soon down here in Florida and will not be able to get hotels in some areas, so I want to be able to sleep in the truck with the A/C at night while I am sleeping. Is it still as big of a problem idling the truck for long periods in the 80-90F weather, or is that more of any issue in the in the colder winters of up north?



Any input would be appreciated.

 

[JoshPeters]

I would think the same problems we have during the winter apply, plus one. Cylinder washing due to idling for so long, etc... . plus... Overheating issues as well as the A/C not cooling due to not having enough air flow across the condensor. Maybe a good electric fan would solve the overheating/ A/C performance. I've been playing around with that idea for about 6 months now. I have an electric fan from a Mercedes-Benz S-class sitting in my garage right now, I might have to size it up tomorrow.



Josh

 

[SuncoastCustoms]

Originally posted by JoshPeters

I would think the same problems we have during the winter apply, plus one. Cylinder washing due to idling for so long, etc... . plus... Overheating issues as well as the A/C not cooling due to not having enough air flow across the condensor. Maybe a good electric fan would solve the overheating/ A/C performance. I've been playing around with that idea for about 6 months now. I have an electric fan from a Mercedes-Benz S-class sitting in my garage right now, I might have to size it up tomorrow.



Josh

I was going to use a fan from the local speed shop. They have then for $75, and they are powerful as hell. I used two on a guys Honda when I did his engine swap for him. So if that is solved, is idling still an issue? If so, what kind of problems would I be seeing?

 

[Forrest Nearing]

just idle it up to 1500rpm or so.



Forrest

 

[Jeff H]

I would say ok. As long as the exhaust temps stay around 300. I've got a lot of idle time. Hot and cold weather. A good fan clutch and good cooling system you'll be fine. May wanna bump the rpms up to 1000 to 1100. Helps keep exhaust temps up. Also when the fan cluch grabs it will spin the fan faster to cool down the a/c radiator and engine radiator.

If you have really big injectors you may not want to do this. May not burn completely.

I've considered the electric fan also. Just never got around to doing it. I think that would be the way to go. I think a little custom work would have to be done to fit one in. May not be all that hard.

 

[Texas Diesel]

Just a thought, if you can find a truck stop nearby. On my last trip to Florida I saw some semi's parked at truck stops with refrigerated air being piped out to the cabs, pretty neat idea. On the same trip we stayed several nights at truck stops and noticed the drivers left the engines on all night. All makes of engines, no e-brake on, no fast idle.



When I leave my 01 ideling in the summer with the AC on it stays nice and cool, EGT is about 200 and coolant is 180F (I have a 180F thermostat) and the discharge AC is 35F. You might want to try it for a few nights and then at the next change have your oil analyzed and see if you have any fuel in the oil. Even though I use extended idle my fuel in oil is <0. 5% with the desired value of <2. 0%.



Am I missing something here?

 

[vssman]

I changed over to electrics this past spring after running all winter without any fan. So far it's been as hot as low 90's a couple of days and I have NO problems with overheating at all. Last week (90 degree day) I went about 400 miles (CT to Mid NJ & back) with traffic both moving 80mph at times & stop/go at other times with temps between 170-190. As a matter of fact, the temp never gets over 190 and the A/C is always cold. I used 2 fans from late 80's Park Aves & a 'universal' thermostat switch/relays, ect... Chrysler makes fans that have flatter motors from Intrepids, etc. . that might be easier to fit.



Disclaimer: I don't tow... So I can't say what would happen if you pull a 20K fiver up a 7% grade out of Death Valley.

 

[rrausch]

Sometimes when I travel across I-40 I'll pull off the road and nap for 30 minutes to an hour or so, in the winter I'll leave the heater on and in the summer I'll leave the A/C on, but I also leave my exhaust brake on, and that keeps EGT's at a little above 300 degrees. But I'd be afraid to do that all night long because of cylinder wash.

 

[SEmerson]

I have let mine idle at 110-120 temp in the summer. No problems yet. While I am sure it brakes down the oil faster and vanishes the valves a little my comfort is more important.

 

[CATCRACKER]

i would say go for it i will just repeat what everyone here said. bump the idle speed up 1000-1100 (also helps the a/c compressor spin a little faster which it needs to) hook up a fan to get some air flowing across the fins helps with the heat exchange. at 1100 rpms with a/c on you will not have to worry about anything. the engine at idle will get very cool no need to worry about it overheating. remember diesels run very cool at idle due to the long stroke and forced cooled air unlike gassers.



these engines were made to work! after about an hour at night trust me you will freeze your buns off



oh yea the a/c blows colder air the slower you set the fan speed in the cab. so i would recommend number 2 setting on recirculate and you will wake up with ice on your blanket

 

[Skydiver]

Just point the truck into the wind. Will help cool it and might help remove the carbon monoxide. Idle it up.