Is this normal?? First PSD 121k 01 7.3 F350, went out first cold morning and started truck, around 25-30F. Started normal, oil psi came up and I went inside for 3-5 minutes. Came back out and truck was ideling around 1300-1500 RPM, can't remember exactly. Touched the brake pedal and immediately went back to idle. Next cold morning, same thing, but I tapped brake at 1000RPM and returned to normal idle. Next cold morning, I put turck in drive and moved it in the driveway. Did not idle up this time. Next cold morning, I let is set where I started it and the darn thing did not idle up at all. I have read that it is not too good to let them set and idle cold, to warm up although I do let it set a few minutes, I can't stand to jump in it and go right away. Any suggestions or is this normal? I have never heard of a diesel to do this. One of my releitaves knows several people who have these and none of them know any thing about it....

 

All newer cars and trucks do this since the mid to late 80's The computer reads the temps of the oil and water and run the high idle until the motor is warm or you touch the brakes.


Fire rooster

 

When the temps get cold enough, this is totally normal. On the 7.3s once it goes to high idle (and starts making the 747-mating-call noises!) it stays there until you touch a pedal. On the 6.0, it will actually drop again, then raise up again, etc. as needed. It's all part of the computer strategy for the engine.

Duncan

 

YEP frobozz, it does sound like a big by-pass, just like a P&W 306 in the test cell! Thanks man. Guess these things are sorta alike, suck, bang, blow.

 

That's aviation terminology for those of you who familiar with aviation.

 

 

actually, I screwed up. It's "suck, squeeze, bang, blow....air pumps will be air pumps either PSD or jet engine.

 

So I take it that it is normal for the idle to go up but is it hard on the motor to let it idle when its cold? Whats the best practice for cold starts? Let it warm up or jump right in and drive?

 

IMO, the best practice is to let it warm up for a minute or so and then drive gently away. It's the cold idle that kills them. It doesn't hurt the motor to work during the warmup cycle. In very cold climates, the motor sucks so much frigid air that it simply won't warm up, fast idle and EBPV closed engaged.
For example: My dad used to live in the mountains of eastern WA. He had a 25 mile commute at a slight down hill grade to get to town. He was driving my late brother's VW Deisel in 20 degree weather and could watch the temperature guage go down and the heater would blow cold. By the time that he arrived in town at the bottom of the hill the engine would be stone cold and blowing white smoke. As soon as the ground leveled off then it would immediatly warm back up again and be fine. All this just from sucking cold air into the intake. On the return trip back home going uphill and even colder weather the temperature guage would ride right in the middle.

 

is youre e brake set?? my truck has a the arctic package and will rev up to what ever its programed to1200 to 2100 for quicker warm ups

 

Thanks for the info!

 

cowboy, yes I think my e-brake was set....not sure now...I just now understood "e-brake". I will try it with it set and without it set and see if it makes a difference
THANKS!!

 

I can only assume this feature is new to the '99's and up? My truck has never gone above 550rpm while idleing regardless of how long I let it idle and we are nothing but cold from Thanksgiving till first of June. And I do mean cold. We've already seen a whole week of colder than -15, including -26 this month. And for the record, I've noticed no assistance from the EBPV on warmup time, so I've disconnected it. And like Kwik said, it has to be driven to warm up. I could idle all day and never reach operating temperature. It takes about 9 miles of 30-35 mph or faster to get to operating temperature.

 

E brake is required to be set or no high idle at cold temps. No need to tap go pedal to make it go down, just release e brake.

 

I've never had to have the e brake set for the high idle to kick in, but then I also don't have the arctic package. High idle will also kick off when the engine gets up to temp, whether it is based off of oil or coolent temps and at what temp I don't know. It will also kick back on in really cold temps if it has been idling long enough to cool down.