Is it bad for a gas engine to idle for extended periods?

[Thundercloud]

I've heard it can be hard on the journal bearing on the crankshaft and connecting rods to let a gas engine idle for too long? I don't know if this is a wives tale or what. The only reason it half way makes sense is because oil pressure is lower at idle. When I start my 440 up I usually manually put my foot on the gas pedal and bring it up to about 1800 or 2000 rpm for about 3 minutes and let it idle for only about 10 minutes at the most before I get in and rev the motor up to recirculate the oil better. Is this really necesarry? I'm a full timer so I'm talking about when I fire it up just to let it run for a bit. I take it out for a cruze sometimes too but With me getting in and raising the rpm it sucks.more fuel. Let me know your thoughts please. Thanks!

[Froggy1936]

T,cloud  Proper way is to make sure engine does not fire till it has oil pressure! With a carburated veh do not touch the accellerator pedal till you have reading on gauge or light is out for a few seconds (99% of bearing wear is from starting) Once you have pressure there should be no metal to metal contact at any surface in the engine except pistons and rings and then not full contact. This is dependant on a good viscosity lube I always use STP (back in my raceing days we would pull the engine at the end of the season leave it sit for 3-4 mo then when opening it for rebuild all connecting rod and main brgs were still wet with oil) This was from the STP fortified oil that does not run off from sitting Z Max & Lucas are the same thing but cost more As far as idleing ity just wastes fuel , But it is better to have a warmed up engine when you are going to start loading it down . THe truckers leave there rigs run for heat/A/C  and most dont pay for there own fuel Revving a no load engine not a good thing . Do not put these additives into a new engine till rings have had time to seat and oil has been changed and warmed up Always add to a hot engine never a cold one  Frank

[Thundercloud]

Yeah I carfully read your response and it sounds like I should invest in a oil pressure gauge. Ha ha. I've just been going off sound. I'm going to install a mechanical oil pressure guage and sender. Yeah I guess the engine is dieing either way when you run it its just a matter of time and I won't rev it up too high without load on it. I usually try to keep the rpm down when it first fires off and yes I use Lucas. I love that stuff.

[DaveVA78Chieftain]

By design, carburetor fast idle is supposed to be set to 1400RPM max in order to allow the engine to warm up.  I wouldn't push it past that during warm up to allow the parts to expand.

Dave

[Thundercloud]

Ok. Yeah good thinking. I'm going to put a tach on it too. The rig has 65000 miles on it but of course those are heavy miles but I'm going to try and make this motor last as long as I can. It seems to run ok which is a good thing.

[TripleJ]

I use to think it was bad to let an engine idle for extended periods.  At my current job our vehicles idle for sometimes 16 hours per day with brief periods of absolute raging abuse.  That means there are vehicles in the fleet with over 10,000 hours and 100,000 hard miles and we rarely have engines fail mechanically.  Its usually transmission, or the vehicles just fall apart around the driveline.

However what I would not do is start it for no reason.  If youre relatively certain your battery is up and your fuel is good, theres really no reason to start it.  Cold starts put a lot of moisture and combustion byproducts in the crankcase, and if you dont intend to run it at operating temperature for a while, all that stuff just sits in the oil and corrodes parts.

I would rather put stabiliser in the gas and the battery on a tender and let an engine sit for 1 year, then start it 2x per month just for the sake of running the engine.

[Thundercloud]

Oh. Yeah I'm just trying to keep the parts moving. I always make sure the thermostate opens and I move the mechanical fuel pump around so the plunger doesn't get funky. I guess it also wards off any racoons, squirrels, beavers,spiders and raindeer.

[Stripe]

And the occasional evil spirit.


But not "Evil GENIUSES!!" Muahahahaha!!

[legomybago]

But not the meeses.....hahahahaahaha