Question for vehicle that sits 5 days a week

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Jan 22, 2005
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I understand about moisture in the oil with it not getting to operating temp, etc. Sometimes time is tight during the week and I can't take my truck for a 20-30 min drive through down in the middle of the week. Would it hurt anything to start it up and let it idle for about 5 minutes to keep the oil moving or just leave it alone. I typically only am able to drive it on Saturday & Sunday due to long work hours. woops: 04 GMC 2500hd 6.0 M1 5w-40 Thanks
 
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A 5 minute idle would be about the worst thing to do as it would not fully warm the oil up (that takes a good run of about 15 miles) and likely would introduce more contaminants into the oil.
 

Mighty HD

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So with it sitting there its not going to "hurt" anything then ie: lack of lubrication, etc? so is it a 20 minute ride or 20 MILE? 20 mile ride around here is about an hour.. Any specific guess on run time/city driving?
 
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Leave it alone if you're not going anywhere. You want to run at least 5-10 minutes after water temperature stabilizes as coolant warms up faster than oil. How long that takes varies from vehicle to vehicle. You want a quality filter, of course, with a good anti-drainback valve, so your first start will get pressure right away.
 

Mud

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5 days? I've got vehicles that sit for months without being driven and they start and run just fine. No 5 minute idle time though, if they are started up they get driven, allowing time to warm up, etc. Oil gets changed really often too. 5 days is cake. Don't worry about it. Drive it on the weekend or whenever you get a chance.
 
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Starting it up and idling for 5-10 min is much workse then not starting it as the oil never gets to opertaing temp and the moisture never burns off as well as other contaminates and the rich fuel mixture at start off never burns the fuel out of the oil as well.. I have one that sits for days or weeks at a time but when I do start it I try to drive it at least 10 miles. The UOA is fine with this regimen.
 

Mighty HD

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Lots of good information here. I thought that starting it up for a few minutes would be safe just to get the oil moving around. Reading this board has turned me into an oil freak. I now have over 100qts of M1, extra filters, worried about drive time, temps, etc. What did I never do before this...
 
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Getting the oil moving around isn't going to make any difference, it's just like everyone said, you'd be diluting your oil with fuel and wearing the engine out faster. Our 78 Chevy plow truck has sat up to a year in between starts and still started up no problem at -25c weather during the first start in a year, with good oil pressure right away. You'd have to leave it sit more than a year before you worry about hurting the engine. The rest of the truck won't like sitting that long though.
 
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Time spend under temp is high wear time and you might be producing more sludge and acid. If you have to make a short trip, don't let the engine run any longer than you have to. Don't try to warm up the engine a lttle extra by letting it idle a bit, before moving. And, turn it off as soon as you stop. Then go for your longer drive and get everyting up to temp.
 
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Many decades ago, a "rule of thumb" was that you needed a trip of 100+ miles to burn off contaminants that could be driven off my operating temperatures. This was when thermostats were in the 160-180F range, though. The reason people should be concerned in those days was they were advised to check their oil level 100 miles into a trip if their cars had been driven short distances most of the time. This was because water could build up to a quart in the oil which would subsequently burn off by about 100 miles. Consequently, what appeared to be a full crankcase at the start of the trip would rapidly drop a quart. For several decades now, thermostats have been around 195F. This sets operating temperature at least 15F higher. Results in quicker burn-off of contaminants. Notwithstanding the hotter thermostat, you still need 30-60 minutes of operation to burn off water depending on what the ambient temperature is. Regards, Gary in Sandy Eggo
 

Kestas

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I used to run my 57 Chevy once a week for 10 minutes when it was in winter storage. This was back when I was 18. The fuel dilution was so bad that after a few months the 5 quart charge turned into 6 quarts! The 10W-40 drained like water!
 
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Forget about any extra 'running' in an effort to burn off any contaminants. A 2004-built vehicle will have fuel injection which pretty much makes the issue of fuel contamination moot. Use a HDEO if you can, but otherwise, just drive the thing as you would normally. There is no harm whatsoever in not driving a vehicle for a couple weeks.
 
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