Hi guys, just a paranoid new owner question here. I live in Montana and we are starting to experience cooler nights. It's been in the mid 20's to low 30's at night lately and when I start up my new truck(just bought pre-owned 2000 cummins with 60K miles on it a couple of weeks ago, 1st diesel for me) in the mornings there is quite a bit of smoke until it warms up. Smoke has blue color to it. How much is normal? I also am curious how long one should let these motors warm up before leaving the drive way when cold started. Also, at what temp. level should I start plugging it in at night, its easy for me as I have an outlet close by. Unfortunately I do not have adequate garage storage so the pickup gets to sleep outside. Any insight or ideas would be appreciated. Thanks RJ in Montana...

 

You don't "have" to plug the truck in at any temp but it's nice if you do because when you get out to your truck in the morning it's already warm and almost as soon as you crank it you have instant heat and can drive the truck. The best thing to do is put the plug on a timer that plugs into the outlet and have the timer kick on about 3-4 hours before you get up in the morning. It's nice having a block heater. I think it's very safe to say that at 20-30 degrees you're gonna see some unburned fuel coming out the tail pipe until the engine gets warm. The block heater should get rid of most of that if used, at least make it act like it's starting up in warmer weather and smoke a lot less. I had a datsun diesel that would cover a parking lot in white smoke on start up until it got warm. My truck puts out a nice little cloud of unburned fuel on cold starts, like any diesel does. It's nothing to worry about as long as it goes away after you start driving it. Once the engine warms up it'll start burning the rest of the fuel.

 

I plug mine in when temps start getting in the low 30's.<br> The truck starts and sounds better, less smoke, and its easier on the batterys as the grid heater don't have to cycle as long.

 

Actually, unless they changed it, the grid heater won't cycle after you reach 19MPH anyway.<br><br>

 

[quote author=MAX340 link=board=4;threadid=6079;start=0#55315 date=1035152688]<br>Actually, unless they changed it, the grid heater won't cycle after you reach 19MPH anyway.<br><br><br>[/quote] <br><br> Right, but I was refering to when your first start the eng it pulls some heavy amps untill you reach that speed, if it hasn't been pluged in.

 

Yeah. The faster the starter turns the more counter voltage it creates and draws fewer and fewer amps. The initial start takes a lot of amps. The slower the turning of the engine at start the more amps is used. The faster it turns the fewer amps from quicker counter-volts.

 

the current draw versus time function of the starter has very little to do with back emf, which I believe is incosequential for starter motors. it has to do with stall current and plain old mechanical work. starter works hard, starter draws more current! ;D