Very long story, but I've been asked to replace the filter and oil in a 3.7 that was drained of oil 6 weeks ago and has been sitting in the garage since then. Is there anything I should know, like should I let the engine stand overnight once I've refilled it to ensure that the oil has got everywhere it needs to go before I fire it up?
Refilling an engine that's had no oil in it for 6 weeks
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twack
Full Access Member
in the perfect worl you would fill it up and prime the oil pump by turning it over either by hand or with the starter. if you do it with the starter you would want to dissable the injectors. but i bet it will be fine
could always pull the plugs and roll or tap it over a few times
everything is going to be really dry after that long
everything is going to be really dry after that long
When you say pull the plugs, do I have to actually unscrew the spark plugs or can I just pull off the coils?
And sorry to sound like a real noob, but what do you mean by "roll or tap it over"? Just give it a few really short bursts on the starter?
And sorry to sound like a real noob, but what do you mean by "roll or tap it over"? Just give it a few really short bursts on the starter?
mmc757
Full Access Member
Its F-ing humid in the UAE.
I would change the oil and filter again after a few hours of operating time because you may have gotten some corrosion in the system while it has been dry.
I would change the oil and filter again after a few hours of operating time because you may have gotten some corrosion in the system while it has been dry.
Humidity isn't really a problem at this time of year, in fact the weather is fantastic between about November and April. Summer is just hell - 120F and very high humidity 
Point taken about another oil and filter change after a few hours of driving. Is corrosion something to be worried about long-term, or will it get ground off the interior surfaces and into the oil when the engine is back in normal use? Would it be worth getting the engine power-flushed before the next oil change?
Point taken about another oil and filter change after a few hours of driving. Is corrosion something to be worried about long-term, or will it get ground off the interior surfaces and into the oil when the engine is back in normal use? Would it be worth getting the engine power-flushed before the next oil change?
67Customs
Full Access Member
It isn't going to be as dry as you think. I've had a 302 motor pulled for three years with no oil and when I pulled the coveres, and the parts still have oil on them.
In my opinion, since it has only been 6 weeks, then I would put the new oil in, fill the filter with new oil, put it on and then start it.
In my opinion, since it has only been 6 weeks, then I would put the new oil in, fill the filter with new oil, put it on and then start it.
twack
Full Access Member
if you are only disableing the sparkplugs then you are washing your cylinder wals with fuel and allowing much of it to go past the rings into the oil, BAD IDEA. if your doing it by hand i would say at least 10 full turns. i would just do it by hand if you can or honestly just toss the oil in and start it up
waywardtravel
Full Access Member
Long time boat engineer. When I worked on trailer boats years ago we winterized them in Washington/Alaska for 6 month storage. You would spray fogging oil down the carb while cranking the engine over to coat cylinders/rings/valves. I opened up plenty of engines for other reasons in the spring that weren't winterized without issue 6mo. later. If your really worried remove the plugs as mentioned spray some penetraiting oil in the cyl's re-install and fire away. Pre-lube pumps are installed on BIG engines for a reason but 6weeks Jeep engine? Just my 2cents
tjkj2002
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Pull the spark plugs out and add about 1 oz of air tool oil in each cylinder.Put spark plugs back in,add oil to the engine(and new filter).Let sit overnight and then start.It will smoke some and you will need to replace the spark plugs but you will be good to go.
waywardtravel
Full Access Member
With all due respect, I'm not going to do the math right now but if I poured 1 oz of thick 50wt oil into a 600 cc cylinder angled at 45 degrees, would I be lubricating the cyl? Where are the ring indexes located and what are they made of? Fog it with a penatrant and start it in my opinion. By the time you re-install the plugs it will have saturated for at least 15minutes. Air tool oil is around, I think 46wt. I think the only concern in an engine sitting for a short period of time would be any rust that has accumulated on the rings or bearings. I don't have a clue what chrysler coats the rings with but they are in the core a high carbon steel possibly forged steel either way, the core could rust if the coating is gone. Hand turning the engine 20 cranks would do virtually nothing in reality because it would only pump oil into the upper valve train the scoring of the cylinders just happened when you cranked it. I would bet you would due less damage/wear starting the six week sitting engine than 42 cold starts that might have happened if that engine was started and brought to temp every day for 42 days.
loves_off_roading
Full Access Member
Make sure you put some oil in the oil filter.
waywardtravel
Full Access Member
That's a VERY good point if filter is changed.
honu
Full Access Member
Lots of different advise...
I like to take a conservative approach to something like this... a little time spent now, may save a bigger hassle later.
My boat sat for several years, hadn't been planned that way, but such is life... After draining and refilling with oil, I pulled the plugs and gave each cylinder a small shot of Marvel Mystery Oil. I let it set over night and before replacing the plugs, I turned the motor over, first by using a socket and bar on the crank pulley (motor was free) then by spinning it over until I could see oil coming up into the valve train.
I replaced the plugs, started the motor and ran it a low RPM until it'd warmed and the smoke from the oil in the cylinders started to lessen.
I increased the revs incrementally, essentially as if I was breaking the motor in. It gives the rings a chance to loosen over time and cleans the bores of any tiny bit of corrosion that may have formed.
I took it through about 4 complete heat cycles, then changed the oil and filter... it looked filthy. After about 10 hours of running, I changed out the oil and filter again... much cleaner this time.
Since then, just regular maintenance... it's been several seasons and the motor runs great. What I did was probably overkill for your situation, but perhaps there were a couple of ideas in there that might help out.
I like to take a conservative approach to something like this... a little time spent now, may save a bigger hassle later.
My boat sat for several years, hadn't been planned that way, but such is life... After draining and refilling with oil, I pulled the plugs and gave each cylinder a small shot of Marvel Mystery Oil. I let it set over night and before replacing the plugs, I turned the motor over, first by using a socket and bar on the crank pulley (motor was free) then by spinning it over until I could see oil coming up into the valve train.
I replaced the plugs, started the motor and ran it a low RPM until it'd warmed and the smoke from the oil in the cylinders started to lessen.
I increased the revs incrementally, essentially as if I was breaking the motor in. It gives the rings a chance to loosen over time and cleans the bores of any tiny bit of corrosion that may have formed.
I took it through about 4 complete heat cycles, then changed the oil and filter... it looked filthy. After about 10 hours of running, I changed out the oil and filter again... much cleaner this time.
Since then, just regular maintenance... it's been several seasons and the motor runs great. What I did was probably overkill for your situation, but perhaps there were a couple of ideas in there that might help out.
Lots to think about, for sure
I was wondering, though - is the situation really all that much different from leaving the car for weeks without draining the oil? I mean, we've left our own Liberty sitting in the garage with the battery disconnected for about 3 months while we were travelling. We got back, reconnected the battery and just fired the engine up without a second thought. No problems at all.
Surely in our case the top of the engine would have been in pretty much the same state, maybe worse, than the engine that's been sitting without oil for 6 weeks?
I was wondering, though - is the situation really all that much different from leaving the car for weeks without draining the oil? I mean, we've left our own Liberty sitting in the garage with the battery disconnected for about 3 months while we were travelling. We got back, reconnected the battery and just fired the engine up without a second thought. No problems at all.
Surely in our case the top of the engine would have been in pretty much the same state, maybe worse, than the engine that's been sitting without oil for 6 weeks?
waywardtravel
Full Access Member
Only difference I think is what oil "might" be held in place by the oil filter and how long it would take for a new filter to fill. In many engines after oil change you can hear the valve train for about 3-5seconds. If it was mine I'd fill with oil and start as long as the old "long story" didn't involve chocolate milk colored oil.
No problems with the old oil that I know of, the job was just started and left unfinished for various reasons, none to do with the Jeep!
Anyway, I guess I've been over-thinking this so I'm just going to go for it. Fit a new filter (which I'll pre-fill with oil), fill her up, let her sit for a while and then start.
Anyway, I guess I've been over-thinking this so I'm just going to go for it. Fit a new filter (which I'll pre-fill with oil), fill her up, let her sit for a while and then start.
J-Thompson
Full Access Member
There is no difference between letting the jeep sit with oil
in the pan or oil drained
I let my Jeep sit for 4-6 weeks often
all I do is start it and let it run for a few minutes before I drive
I have been doing this for years
in the pan or oil drained
I let my Jeep sit for 4-6 weeks often
all I do is start it and let it run for a few minutes before I drive
I have been doing this for years
Before I got married, my truck used to sit routinely for 6-8 weeks (regular cutter deployments/patrols) every 2 months. When we got back, I would walk off the ship to the parking lot, check the oil & trans fluid, then let it warm up before moving it. This truck runs 14 second quarter miles, will do at least 130mph and has over 114,000 miles on it. If you're really worried, pull your coils, take your plugs out and spray some fogging oil in the cylinders. Add a little MMO to the regular oil and run it that way for awhile, then change the oil and filter again. Unless you got a whole bunch of condensation or crap into the sump, it won't make that big of a deal.
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