Idle Hours!

[2wd]

How many idle hours you got? Compared to total hours?

What's considered high idle hours?

There are some reports of the 5.7 used in police chargers racking up massive amounts of idle hours. Some reports of problems but also some trouble free. From what I've read, when idling, sometimes the lifters aren't getting sufficient oil flow compared to when running 1000+ RPM.

I've got 450 total hours, with 50 idle hours. ~13k Miles - (mostly idling from remote starting in the winter) That's 11% of hours at idle.

 

[Fatherof3]

I’d have to check but I’m sure I’m over that

 

[Ramaroo]

... From what I've read, when idling, sometimes the lifters aren't getting sufficient oil flow compared to when running 1000+ RPM.

That sounds abysmal.

 

[Mr. Hindsight]

Here’s mine...

 

[Dusty1948]

I have 28 Idle hours; 1080 Total hours.
Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 17 July 2018. Now at: 031844 miles.

 

[Diamondback]

How many idle hours you got? Compared to total hours?

What's considered high idle hours?

There are some reports of the 5.7 used in police chargers racking up massive amounts of idle hours. Some reports of problems but also some trouble free. From what I've read, when idling, sometimes the lifters aren't getting sufficient oil flow compared to when running 1000+ RPM.

I've got 450 total hours, with 50 idle hours. ~13k Miles - (mostly idling from remote starting in the winter) That's 11% of hours at idle.

You are correct .. my Master Tech does nothing all week but rip apart the top and replace cams/lifters on vehicles "with too many idle miles (oil pump wasn't 'designed' for idling all day I guess, and fails to keep up enough pressure)."

Remote starting isn't that bad as the oil is cold and there is plenty of pressure. This appears to be those the drive ALL day allowing the oil to thin out too much and idling for (let's say) 30 mins or more?

 

[Dusty1948]

You are correct .. my Master Tech does nothing all week but rip apart the top and replace cams/lifters on vehicles with too many idle miles (oil pump wasn't "designed" for idling all day I guess, and fails to keep up enough pressure).

Remote starting isn't that bad as the oil is cold and there is plenty of pressure. This appears to be those the drive ALL day allowing the oil to thin out too much and idling for (let's say) 30 mins or more?

I've read this theory a number of times but I'm not sure it makes sense. Have you ever seen a 5.7 motor oil pressure lower than 20 psi at idle? All of my 5.7s idled at 28-35 psi hot from the day I got them to the last day I owned them. Factory spec's call for a minimum of 4 psi at curb idle. None of the Mopar techs I talk to seem to agree with that theory. Of the cam failures I've seen pictures of there is usually only one lobe/lifter roller failure. If the problem was insufficient oil flow at idle speeds to the valve train I would expect to see aggressive and uniform wear on all or most of the lobes.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 17 July 2018. Now at: 031844 miles.

OIL PRESSURE

DESCRIPTION​	SPECIFICATION​
​	Metric​	Standard​
At Curb Idle Speed (MIN)*​	25 kPa​	4 psi​
@ 3000 rpm​	170 - 758 kPa​	25 - 110 psi​
* CAUTION: If pressure is zero at curb idle, DO NOT run engine.​

 

[ScottMA64]

I have just over 9000 miles on my 2019. Last time I looked, which wasnt that long ago, I had 261 drive hours and 251 idle. My idle hours are long because I sit in my truck during my break times at work. Gotta keep the engine running to keep cool/warm and keep the battery charged when listening to the radio.

 

[Diamondback]

That was the exact same thing I pointed out (asked), @Dusty1948

"does it seem to (almost) always be the same cylinder?" .. for me, I've noticed it seems more and more like Cylinder 5 (which starts with a MISFIRE #5 complaint).

anything less than 15 is way to low on any vehicle, I don't agree with the FCA Engineers on that one.

 

[airgas1998]

the lifter/ cam lobe failure is NOT do to extensive idling. it's an inferior alloy not being properly hardened.

 

[Diamondback]

Agreed. -- editing my original post to add the QUOTES to what he said, for clarification.

 

[Dusty1948]

That was the exact same thing I pointed out (asked), @Dusty1948

"does it seem to (almost) always be the same cylinder?" .. for me, I've noticed it seems more and more like Cylinder 5 (which starts with a MISFIRE #5 complaint).

anything less than 15 is way to low on any vehicle, I don't agree with the FCA Engineers on that one.

Most people nowadays will find the 4 lb. minimum extremely incredulous, but I think that's because of a lack of understanding. Anyone familiar with small block Chevy motors, especially the A-H series, would not find that spec terribly concerning because factory specs at 4 lb. curb idle are pretty common in older GM motors.

What must be understood is that is a field spec for engines in minimum condition. Mopars in particular have a history of higher oil pressures and I'm sure those working around 5.7 Hemi motors would react abruptly to idle speed oil pressure that low. (A tech. would also be measuring the oil pump pressure at the higher RPM to see if it's still in spec.) I think what the factory spec is telling us is 4 lbs. of oil pressure at curb idle is the absolute minimum to run the engine at idle speed without damaging the engine. You'd probably never see one that low unless there's some serious internal wear.

One of my son's just sold a 2003 Hemi with nearly 200,00 miles on it, and the hot idle oil pressure was still over 25 lbs. And that was with 5-20W oil.
Best regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 17 July 2018. Now at: 031853 miles.

 

[Diamondback]

Mine has yet to fall below 15 itself, too.