High Idler for warm up?

[Dave MacArthur]

Anyone know the pros and cons of using the High Idler for warming up. I'm wondering if it would be ok to let the truck high-idle for a few minutes (5/10) after startup. I would of course let the oil pressure come up and wait a minute or two before turning it on. Is it better to be under load when warming up (ie. driving) or would this be ok?



Thanks,

Dave.

 

[Bigsaint]

David, I'll answer with this reply... before I had the ebrake, I built a high idler out of a piece on 3/8" threaded stock and a turn buckle. I used this whenever the truck was idling for warm up, keeping the rpms at 1200 or so. When my stock injectors came out for a upgrade to step 3's, the existing injectors looked like crap, really gummed and sooted up. When the step 3 injectors came out, they were spotless ( using the ebrake for warm up/extended idiling). Based on that experience, I suggest plugging in for a few hours before you leave, start it up, wait for the oil pressure to come up and then drive. Try to keep the rpms at or below 2000 until you come up to temp. and don't lug the engine. I don't think that a high idle alone is enough to work the engine and prevent wash down in the cylinders when it's cold. Another great reason to add an exhaust brake when the budget allows.



Scott W.

 

[DennyDay]

Hi Idle

Been using a fast idle for 104k miles with no adverse effects. I also use the fast idle in the field for hours at at a time. Checked injectors at 60k, they had normal carbon with that kind of mileage.

Denny

 

[Neal Cassady]

Warm Engine versus Warming Up

IMO fast idle is good for keeping a warm engine warm. I use it in conjunction with the Defrost setting to keep the EGT's up in extended idle situations.



I don't think it is a good idea to use it to warm up a cold engine.



Dave

 

[LSMITH]

I have to agree with Dave D, I would not use one for warmup. Try it yourself. Get in and start it, then hold the RPM at 1200 and see what happens with EGT and engine temp. I have done this and not seen the need for a high idler.

 

[GSchlegel]

LSMITH - I agree. At any engine (coolant) temp or OAT I have only seen a 21 degree increase in EGTs on a digital gauge if I idle at 1200 RPM vs. 800 RPM. For at least a year the high idle for warmup arguement hasn't made any sense to me and I point it out as often as anyone posts about it.

I think this idea goes back to gassers that most of us were familiar with.

I read on TDR once that the Cummins at and near idle runs at 65+ to 1 air/fuel ratio. We all know our trucks under no load at idle have EGTs well under 300 degrees.

Sorry I got carried away, but the logic of high idle for warmup escapes me (the exhaust brake for warmup does make sence, wish I had one).

Gene

 

[Jeff H]

I've been doing high idle thing since I got the truck at 54,000 miles on it. I have 161,000 on it now. I had injectors checks and were fine. I never let it idle more than 10 minutes.

After it I let it idle. I get on the throtle and go. Get those egt's up right away to get the stink out.