8,300 Idle Hours

Tech discussions on the L77 6.0L V8.
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impalaplt
Posts: 67
Joined: Fri Jun 18, 2021 3:50 am
Location: Tucson, AZ

8,300 Idle Hours

Post by impalaplt »

So, my car is fairly low miles, but kinda high on the idle hours....

I KNOW I need to do the DOD delete, and I'll probably do an upgraded cam too....

BUT, since this has quite a few idle hours, should I go into the engine, and replace things?

It's a 2015, with about 55,000 miles on it now.
Fandango
Posts: 67
Joined: Fri Jun 12, 2020 12:31 am

Re: 8,300 Idle Hours

Post by Fandango »

Not unless it starts showing signs of needing it. An oil analysis might be able to spot an issue, but I think they like to see a few, so they can see a trend.
HoldOn SV

Re: 8,300 Idle Hours

Post by HoldOn SV »

Those numbers are makin' me brainert.
GammaFlat
Posts: 259
Joined: Mon Sep 21, 2020 9:26 am
Location: NW Indiana

Re: 8,300 Idle Hours

Post by GammaFlat »

In theory, multiply the number of idle hours times 33 (as in 33 mph which is an average speed a car travels in it's life). 8300*33=279,900. Now, that's only wear on the engine, accessories (alt, compressor, water pump, idlers). The big things to worry about are the engine internals which are the hardest to address.

The two key indicators to consider are compression test and oil pressure.

The compression test indicates how your valves and rings are doing. The oil pressure indicates how your bearing clearances are doing (crank and cam).

If your oil pressure is low, you may have growing clearances which bodes not so well of longevity of your engine. If both of those measures (oil pressure and compression) go well, sleep well. If they don't, these things are not expensive to address: put new bearings in (5-700 after gaskets).

Rings and/or valve job on heads might be more involved (machine work on cylinder walls and new pistons / valve job on heads). I think minimalist head work is 500 bucks. Cylinder walls and new pistons are closing in on 1K (clean block, gasket kit, bore, new pistons/rings).

The good news is that any of these upgrades open the door for more upgrades (in no particular order)
1: $1000 for a 4 inch crank gets you a 402 cubic inch torque monster, admittedly, you'll also need rods and new pistons
2: new pistons.. opportunity for compression ratio play
3: CNC port work on heads, valve seats, better springs, lighter, self cooling exhaust valves - or just buy new really nifty ones :)
4: upgraded camshaft which of course includes lifters, pushrods, springs 1K-ish

Most of my assumptions include you assembling at the end of the day.
Current: 2013 9C3, deeper trans pan, 12VoltSolutions Remote, Class III hitch, Android Auto capable radio
BluesBro
Posts: 134
Joined: Tue Aug 03, 2021 1:26 am

Re: 8,300 Idle Hours

Post by BluesBro »

My car has 16k idle hours, compression was good, oil pressure was good. With the DOD deleted I don’t really worry about it, I send it every day. I don’t run the rev limiter up as high as the lower hour cars we have(6200 vs 6700) but other than that I’m not terribly worried. It does seem to be in need of starter, but all other accessories are in good shape.
2014 Caprice PPV 6.0L - TSP Stage 1 Cam, Solo 3in Mach Cat Back, VCM OTR, Pedders Coilovers, HP Tuned
2002 Avalanche 5.3L - MBRP Exhaust, RC 6in Lift
Sanford
Posts: 356
Joined: Mon Dec 12, 2016 9:38 pm
Location: Texas Gulf Coast

Re: 8,300 Idle Hours

Post by Sanford »

I would consider the amount of gas burned to play a bigger roll in the amount of engine wear. A idling engine that burns 1/2 gallon an hour does not have much of a load on reciprocating parts as a pickup pulling a trailer that is burning 5 gallons an hour. Some of the other accessories may suffer from the idle hours such as fuel pump, cooling fans and AC compressors.

The 33 miles per hour calculation fits better if the engine is being worked, such as a earth moving equipment or generators. Most of their run hours are working hours.
anwat
Posts: 23
Joined: Thu Jan 19, 2023 1:06 pm

Re: 8,300 Idle Hours

Post by anwat »

I know this is an old thread, but I've got to throw this in for consideration: You're using a average vehicle speed of 33 mph to calculate. Maybe if that vehicle was a highway patrol or state police vehicle, that would be accurate, but on a municipal vehicle, I don't even think it's close. All of the urban black and whites I've gotten into in the last few years have an average speed on the life of the car as being under 10mph, and that isn't including idle time in the average. Admittedly, I'm in SoCA , so the traffic is a bit worse here than elsewhere, but the job is different for a city cop, at least as far as driving goes.
The load the engine is under is also mentioned. Those city agency vehicles are a lot more likely to have wide open throttle runs several times a day than others. Another very real consideration is the number of left handed U-turns made at speed. It has to take a toll on suspension parts after a while.

I don't necessarily have a better number to use, but wanted to throw out those facts so folks could use them when assessing vehicle condition.

One other thing: While you probably won't know for sure, but cars without partitions will generally be in better condtion than those with. Vehicles driven by or assigned to detectives, SROs, Watch Commanders and other administrative positions won't see the hard use the patrol pool cars do. They also get maintained more regularly, since someone is responsible for the car...when something breaks, they take it in rather than just waiting for the next guy who drives the car to do it. So if it's overheating, it only does once before the mechanic gets it. The patrol car may do it 5 times before someone finally does a repair slip on it.
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