Periodic Idling During Extended Down Time
 

A philosophical /perhaps controversial question if I may. For the last several weeks I've been working on the slow and tedious process of rust repair on the floor panels of my Discovery 1. One or twice a week (usually when working on grinding or tacking) I will run the engine for ~15 or 20 minutes. I thought this was the right approach to keep things moving and bring the engine to temperature, however now in reading some online opinions I'm noticing some folks say that if you can't take the engine though a good driving cycle (warm up, varying RPMs, extended time at high RPMs) then the engine shouldn't be run at all. Anyone inclined to give an informed opinion on if the Rover V8 is particularly subject to risks with my approach? Is it better to just leave it alone for a few *months? while I do this work in the driveway?

I have numerous vehicles and classic's I only drive a few months in the summer and they sit the rest of the yr (incl my Disco). And that's how it's been for 20 years (25 yrs for a couple). And my brother does too ...so do a few buddies of mine who have a lot of 'classic' cars or trucks they don't drive in the winter. None of our vehicles have shown any degradation and nothing's 'blown-up', engines are clean inside, etc. We don't use Sta-bil ..and all the fuel we have has ethanol in it (except the Disco only gets non-ethanol premium).

Most of my vehicles I don't drive in the snowy/salty winter. So they sit all winter, some outside, some inside, some in heated or unheated environments. I may start them up once over the winter if we have a particularly warm series of days and the roads are very clean/dry. May drive up/down the driveway or cul-du-sac to clean off the rotors, then it's back in place. But only after the engine has fully warmed up and the water evaporate out of the exhaust. My Jeep Cherokee is a plow truck and I usually put insurance on it, say, Jan 1 and take off at end of March or sometimes in April or May 1, depending on how snowy it is. I change the oil on the plow truck once every 3-4 years (I use Citgo Synthetic). My Trans am I hadn't started and ran in probably 5 years ....lol. But I unhook my vehicle's batteries when I know they aren't going to be used a while, but I shake the batteries and charge them periodically to keep them up (shake to de-stratify the fluid inside).

So, no. Don't worry about it sitting for a period. You're going to get a lot of opinions from people who get their info off youtube. The main thing you want to do is keep yer rotors from rusting too much. If you do start it up when it sits for a while, I recommend doing one of two things: 1) Say you start it up a little more frequently -- run it for about 30 seconds or a minute, turn on the defrost (to activate the ac compressor) then shut it off. You just want to circulate the oil and coolant but not warm the engine. Then the engine doesn't warm up enough to build up condensation inside, or load your exhaust (muffler) with moisture. That moisture along with combustion byproducts creates a carbonic acid which is about the acidity of orange juice. Let it sit in your exhaust long enough it'll prematurely rot out your muffler. But if it's in the winter time, like me, it's really too cold for meaningful oxidation chemical reaction to occur. But too much combustion water in your muffler ...in the cold north (and a muffler can fill 1/2 way with water), can freeze solid and bust a muffler ..so you don't want to load your muffler up with water by constantly starting, let run, then shut off w/o unloading the water from your muffler (unless of course you want a 'split' muffler).

Or ....2) Start the engine and run the engine until it's fully warmed up and the hot exhaust has evaporated the water out of the muffler (driving it really helps empty the muffler). Probably 20 minutes or more. I say, Muffler bc it's in the rear on these disco's and takes a while to get it warm/hot enough to evaporate the water completely out.

Often in the summer before I start to drive the Disco (or some of my other vehicles which sit a while), I'll put it up on jackstands, pull the wheels and compress the calipers (and pedal them back out) about 3x in/out per caliper to ensure the caliper pistons are 'free' ...and maybe hammer the pads with a sharp blow to ensure they're 'free'. On my Jeep cherokee plow truck that sits all summer, each fall before I drive it, I remove the front calipers and run them in/out, clean off the rotors with 80# sandpaper, and lube up the brake sliding surfaces. Sometimes I need to run a file over the brake sliding surfaces on that rig bc corrosion often occurs with some salt that may have not fully washed off since the past spring. I also exchange the brake fluid every few yrs too (I have a brake exchange machine).

Pretty much all farmers and construction company owners have a number of pieces of equipment, tractors, skid loaders, harvesting equipment, gravel crushers, paving equipment ....and so on that only gets certain times each yr and many that get used very sporadically. For example in the winter tractors w/o heated cabs may sit, or not get used much. These folks don't do any special to 'put to bed' or spring 'wake-ups', whatever, they run them as needed sometimes with LONG gaps between, and have been since the 1950's and earlier, and, look, they don't have engines that crap out prematurely. The idea that the oil needs to be changed every 3 months, or you need to use Sta-bil ir other processes are modern urban myths. But just follow some simple guidelines to keep moisture down and circulate the 'juices' periodically. Keep water and rodents out and the battery charged. Do your basic maintenance as required as well.

If you're not going to run your Disco for a few months, follow my suggestion (do a search) and install a piece of hardware cloth (screen with 1/4" holes) over the open hole to your heater blower (remove the plastic cowl piece in front of the windshield). Keep the mice out of your heater blower/heater system. They can litterally create a smell that will make your eyes water going down the road and make your Disco uninhabitable! Don't put it off till it's too late, or you'd wish you did (just sayin'). It'll take a LOT of work to undo ..don't ask me how I know.

Hint 2: check and adjust the pH of your vehicle's coolant so it doesn't 'rot' out your heater core. Aluminum in a low pH environment acts as an anode and literally get's scavanged into the coolant. Thats not so bad, except the aluminum is paper-thin in the heater core. There's a very narrow range of 'happy' pH when you have mixed metals (Cast Iron & AL). But that pertains to any vehicle weather it sits or not.

That reminds me I need to get my pH tester going this fall yet.

Thanks Mark for the advice and reality check! Great information and good context to know it is common to leave these engines/all engines out of service for a period of time with the right preparation and commissioning steps. I'll leave mine off for the next few weeks as I finish up the body work.
Thanks again!