generic oil change question

[60thAnivrsryXJ]

Ok I would like to know how many people think this is a good idea. You change your oil and then you refill it until the dipstick reads full then run the engine for about a minute and then check the dipstick again and add more oil until it reads full again.

 

[5-90]

1) Drain Oil

2) Remove Filter

3) Lubricate gasket on new filter

4) Install new filter. Install to "contact" (gasket touches metal surface) then NOT MORE THAN 1/4-1/2 turn

5) Refill with six quarts of your "oil of choice."

From what you're saying, my line of thinking is that you're going to overfill your oil. When you shut your engine down, it takes 2-5 minutes for all the oil in the upper engine to drain back down into the oil sump, and then get a good reading on the dipstick. This is why I check my oil AFTER I pump gas, not BEFORE.

While overfilling your engine oil may not sound like a very bad thing, it is a bad thing. Overfilling you engine oil can result in excess "windage" - oil being beaten into the air and then causing drag on the crankshaft. It's also possible to overfill to the point where the sump is so full that the crankshaft actually hits the surface of the oil - and both of these conditions will cause loss of power, and accelerate bearing wear.

No - just pour six quarts into your straight six and call it done - it's easier. They don't just pull fill specs out of the air, you know...

5-90

 

[AJPulley]

I agree. Use six quarts. If you really feel the need, check the dip stick again only after the egine sits for a day so all the oil has time to drain back to the pan.

 

[XJ_ranger]

im not sure he was asking for a cherokee specificly...

just in general...

 

[5-90]

Well, this is a Cherokee board, so that's the context in which the answer is given.

However, I'd not do something like that. I might run the engine for a while, but I'd check the oil AT LEAST an hour later - again, to allow for total drainback of the engine oil, and to prevent "false lows" from being read at the dipstick.

In my experience (about 25 years, give or take) I've found that using the "fill spec" for the oil change suffices nicely...

5-90

 

[BCParker]

relating to this oil fill level question,

If I'm using the bigger filter, (napa1515)

do I fill 6 quarts and then try to eyeball a half of one, or do I go by the dipstick, waiting a few minutes between checking of course?

or do I just try to fill up the filter before screwing it on, then add 6 quarts?

or... do I just say screw it and get the original filter?

 

[5-90]

You could eyeball it, or just have a pint cup or bottle handy (a pint is a half quart) or just use some sort of measuring cup to make sure.

A few ounces over isn't going to matter, I'd even be willing to bet that a half-pint is OK - but I'd prefer to measure than guess. Maybe I'm just picky...

5-90

 

[60thAnivrsryXJ]

Yeah it was meant to be generic. I don't actually do this in any onf my vehicles, I just pour in what is called for. That is the way they try to make me do it at work and I don't agree with it. I ended up puttin like 5 and a half quarts in a little honda 4cyl the other day at work and I hope it messes somthing up and they have to buy the guy a new engine. They say you gotta do it to fill up the filter but see if you agree on this. I could be confused about the way oil filters are made but... Doesn't the oil just go through the bypass until it gets warm enough to flow through the filter. So a minute of operation would not accomplish that would it.

 

[Matthew Currie]

Yeah it was meant to be generic. I don't actually do this in any onf my vehicles, I just pour in what is called for. That is the way they try to make me do it at work and I don't agree with it. I ended up puttin like 5 and a half quarts in a little honda 4cyl the other day at work and I hope it messes somthing up and they have to buy the guy a new engine. They say you gotta do it to fill up the filter but see if you agree on this. I could be confused about the way oil filters are made but... Doesn't the oil just go through the bypass until it gets warm enough to flow through the filter. So a minute of operation would not accomplish that would it.

No. The oil filter in any modern car is "full flow," which means that all the oil flows through it. The bypass is not thermostatic but opened by pressure. It opens if the filter is too clogged to pass all the oil needed, so that the engine does not starve. If you fill to the dipstick before running the engine, the level will go down by the capacity of the filter after running even a short while, perhaps even after cranking, and you should add that much. However, if you put in the amount called for in the specs, this will include the capacity of the filter. Many owners' manuals specify an amount with and without filter change for this very reason. If you are filling to the dipstick you should always wait at least a few minutes even when the oil is hot, for the oil to run back to the sump.

If the people at work are making you add more than the recommended amount, they're wrong. It probably won't kill the engine but it will waste oil, and if it's really too much it might burn off faster and increase pollution and cause premature plug fouling, as well as causing unwanted splash and turbulence in the sump. If you add too much it might also cause excessive crankcase pressure and blow the seals, but I doubt that will happen unless you really overdo it.

 

[cmotsvt]

How about just refillling with the same amount that you removed?

 

[BCParker]

How about just refillling with the same amount that you removed?

Bad Idea

after running for 3000miles or more, you're bound to lose some oil, so the amount you got out can be anywhere from a few ounces to a few pints less than what you would put in. (depending on how many oil leaks you have, and how much you just plain burn up)

in regards to my earlier question about the larger oil filter, I've decided to just forget about it for now. - after reading around, and seeing the weird way the larger filter hangs on to the oil filter adapter (looks like it could just blow off if it were to be jolted at all), I'll stick with the same size that has always been on there, and six quarts of oil.

 

[90Pioneer]

The people who are waiting days or hours to check their oil aren't doing it correctly. Your oil should be checked with your engine warm and at operating temp.

If you just drain oil and pour six quarts in, most likely you're going to be over full. You aren't draining ALL the oil out when you pull the plug. Or at least it would take hours, if not days, for you to do so.

Fill your motor up with 5.5 quarts, run motor for a minute or so, shut down, wait a couple minutes, and check oil level, and add as needed.

 

[60thAnivrsryXJ]

I know the oil filter bypass isn't thermostatically operated but I have a teacher who says that when you first start your engine the oil is thick because its cold and it doesnt flow through the filter it goes through the bypass. He says you should always let your engine warm up for 2 or 3 minutes before driving, otherwise you are lubricating your engine with unfiltered oil.

 

[Matthew Currie]

I know the oil filter bypass isn't thermostatically operated but I have a teacher who says that when you first start your engine the oil is thick because its cold and it doesnt flow through the filter it goes through the bypass. He says you should always let your engine warm up for 2 or 3 minutes before driving, otherwise you are lubricating your engine with unfiltered oil.

The theory makes sense, but I would not wait before driving, since unfiltered oil will do no more harm when gently driving than it will when idling, and driving will warm it up faster. As soon as you have oil pressure (and that had better be about the same time the engine fires) you're good to go.

I suppose if you're changing oil in serious cold outdoors it would also make sense to run the engine a few minutes before trusting that the filter is full, but I've never noticed any discrepancy even though I do often change it outside in the cold, and even inside, my shop thermostat is set to 40 when there's any fuel in the heater, which is rare enough.

As far as it taking hours to drain the engine, I also disagree with this, assuming that it is well warmed up. You can try it sometime if you wish. Warm it up good and hot, and drain it for, say, 15 minutes. Now pull out the drain pan and put a fresh one underneath. Come back in a few hours and see how much oil is in the new pan. Not much, I'll wager. Not enough to worry about overfilling if you put the plug back in after 15-30 minutes and put in the specified amount of oil.

 

[mikecooper]

Im gonna have to go with 5-90 on this one. I own a lube shop and always go by the specs, although we fire it get the oil pressure up let it sit for about 2 secs(nissans with the goofy stick have to sit for about 5 min). Then check the stick, if you KNOW it takes "5qts" then check it till it reads 5qts. As for the Honda haha good luck the 3.5vtec holds 5 and for the 4cyl try 3.5-3.9 at best. The newer vtec 4cyl sometimes hold 4.4

 

[cmotsvt]

Bad Idea

after running for 3000miles or more, you're bound to lose some oil, so the amount you got out can be anywhere from a few ounces to a few pints less than what you would put in. (depending on how many oil leaks you have, and how much you just plain burn up)

Maybe I'm just a crazy old man but I check all fluids (yes, even brake fluid) and tire pressure every weekend.

 

[MyJeepXJ]

My 4 Oh uses 6 quarts, I just dump it all in. I got a slow leak and a mild burn, I gotta keep checking it every 2 weeks anyway.

Im now getting WalMart oil & filter, a complete change is less than $10, so Ill probly change it every 2 months now since its cheap insurance!

 

[splitz]

Instead of starting a new thread, I figured I'd post on this one.

I changed my oil and filter, replaced with 6 quarts and let it idle for a while. Then I checked the level, and it was really high on the dipstick. Can anyone tell me what the heck is going on?

 

[Beej]

Well, if you're absolutely sure you put in six and not seven, then try wiping the dipstick really well before measuring again to ensure its not just pulling up too much oil. Otherwise, maybe someone swapped in a longer dipstick to mess with you?

 

[Lawn Cher']

Well, if you're absolutely sure you put in six and not seven, then try wiping the dipstick really well before measuring again to ensure its not just pulling up too much oil. Otherwise, maybe someone swapped in a longer dipstick to mess with you?

I wish my dipstick was longer.