damage from driving off before oil pressure builds

[The motor guy]

I see so many people that just get in their cars start them up and they have it in gear and moving the second they take their hand off the key. I think a good example of this would be the UPS drivers that shutoff their engines at every stop and start them up again. How much does this hurt the engine/ transmission? You would think you would be slamming the clutch plates together on the transmission. What do you guys think about this? How often do you guys see this? Just curious.

 

[AuthorEditor]

The pressure builds within a second or two on vehicles I drive. Especially when warm I doubt there is any significant problem, but when cold it is probably better to wait at least a few seconds. This is one good argument for using filters with effective ADBVs--cuts way down on the lag in oil pressure build up.

 

[IndyIan]

Unless you have a cold start in temps near the pour point of the oil, the oil system is pressurized in a second or two...
Hot starts after 5 minutes of shut down probably have almost zero effect on the engine.
You might be able to damage an auto transmission if you rigged up a car to start with the transmission in gear. But a normal start in neutral or park will have the transmission fluid system pressurized before you could pop it into D.

 

[The_Jeff]

If anyone's done a cost benefit analysis it's UPS. Their fuel savings must beat all the extra work on the starter and just-started engine.

 

[The motor guy]

You ever notice how fedex leaves their engine running while ups shuts them off? Not to get off topic. Just figured id mention it.

 

[demarpaint]

IIRC UPS comes down pretty hard on their drivers if they don't shut the engines down when they stop to deliver a package. Eljefino nailed it, if anyone spent time and money doing research on the cost effectiveness of shutting the vehicle down at every stop it was UPS.

 

[opus1]

+1 on the above. I've noticed this week that the Dakota is hesitating a bit to build pressure due to the ridiculous cold, but within a couple of seconds the pressure is built up. At some point I need to get some synthetic in there, but that's beside the point.....

If anything, I'd think transmission and differential issues would be a bigger problem from starting the car and flooring it right away.

 

[4ever4d]

Originally Posted By: eljefino
If anyone's done a cost benefit analysis it's UPS. Their fuel savings must beat all the extra work on the starter and just-started engine.

I used to drive for a large carrier and we were told to shut down at every stop,as a matter of fact we had a 3min auto shut down on the truck computers.Starters could be replaced on the whole fleet for a quarter the cost of fuel loss on 5min idle times,idle was a "write up offense".

 

[AuthorEditor]

By the way, this is a good time to mention the obvious point that Delo 15w40 is good stuff, but something like Rotella T6 5W-40 would give you better cold flow properties on start up.

 

[AuthorEditor]

Quote:
Starters could be replaced on the whole fleet for a quarter the cost of fuel loss on 5min idle times,idle was a "write up offense"
.

State motor vehicle law here in NY is that heavy duty trucks are not allowed to idle for more than 5 minutes. I think that includes school buses and smaller delivery vehicles now too.

 

[Jeff3126]

On some days, my truck goes a full 9 hours without a shut down.

 

[Vikas]

Most of the hybrids routinely shut off the gasoline engine and restart them many times during a trip. If the engine is warm, the oil pressure should build up instantly. If you are looking at mechanical pressure gauge, that might just have the lag.

 

[Craig in Canada]

Originally Posted By: demarpaint
IIRC UPS comes down pretty hard on their drivers if they don't shut the engines down when they stop to deliver a package. Eljefino nailed it, if anyone spent time and money doing research on the cost effectiveness of shutting the vehicle down at every stop it was UPS.


I think it's also risk of vehicle theft, not just fuel costs, that factor into a policy whether to shut down or not. I once saw a major courier's truck get stolen right in front of him. He left it running with the door open and a guy stepped in and drove off.

There's also "public percpetion" - Why is that delivery guy idling his truck? He's killing the polar bears! - which has nothing to do with fuel cost.

 

[bullwinkle]

Could be wrong, but don't most UPS trucks have air start (sounds like it) which would be easier on starting?

 

[nazareth]

thery dont shut their vehicle off to conserve fuel its company policy with ups and usps any time they get out to shut it off so the vehicle isnt stolen

 

[mikiee]

The most wear on the UPS engine is the first start in the morning. Once the oil is warmed up, it's not an issue.

 

[CBR.worm]

Most of the heavy equipment I work on automatically shuts off after 8 minutes of idle time.

 

[Pop_Rivit]

Originally Posted By: motor_oil_madman
I see so many people that just get in their cars start them up and they have it in gear and moving the second they take their hand off the key. I think a good example of this would be the UPS drivers that shutoff their engines at every stop and start them up again. How much does this hurt the engine/ transmission? You would think you would be slamming the clutch plates together on the transmission. What do you guys think about this? How often do you guys see this? Just curious.


I'm not sure that I could start any of my vehicles and then get them moving before oil pressure builds.

I doubt that it harms the drive train at all unless it's driven hard before it's reasonably warmed up.

At least none of my modern vehicles have ever had an issue with being driven right after being started. That being said, I once had a '58 Chevy Apache pickup that was absolutely cantankerous until it had warmed up for about 5 minutes. But I haven't had an issue in the last 20 years or so on a well maintained vehicle.

 

[Errtt]

I could see no problem on a warm start, but for the first cold start of the day shouldn't be too bad as long as one doesn't try and throttle hard under load.

The most common place I see folks get going immediately after the vehicle has been sitting awhile is leaving work - they want to hurry up and get on the road to home.

Myself, I get settled before dropping it in gear - cell on, gps on, radar detector on, radio on, seat belt on, and if I don't need to defrost the windshield, then I'll drive off but no high revs and I keep the throttle load fairly light until the temp is up about normal.

 

[cbear]

I could be wrong, but I thought UPS had a kill switch on the driver's seat.