No, we do not disagree on much. I agree with you the right amount of oil should be in the engine. But in my business, we need the oil at the top of the full range when we are done with service. My customers are charged with keeping the levels checked and full between services. The only way that can happen is if they have a stick to read. Unless there is a specific problem to fix, my customers are not going to pay for services that leave the oil over or under full on the stick. I will suggest that pretty much any auto service business is in the same boat.

The real problem here is that you do not know if the "defect" that causes the oil to read full at 5.5 quarts is causing you to have the right depth oil in the pan or not. A pan that was stamped too small would require less oil for proper oil depth. Fill it to 6 quarts and the oil could be hit by the crank and rob power and foam (granted, unlikely). OR it could be a shoddy dipstick and tube, which leaves the oil too low. The engine will starve for oil sooner if something goes wrong.

In the end, my reply was a response to the original post. The oil level is being read incorrectly based on a "wipe off in the tube" theory that does not hold true. Try it (I have), you cannot replicate it with a dipstick, tube, and a quart of oil. I don't doubt (as I already stated) that the oil reads full at 5.5 quarts. The only place we disagree, if anywhere, is that I fill it to the full mark and drive it. You do something else and hope that the spec matches the manufacturing of the rest of the engine close enough that you are ok. In the end, despite our different methods, we are both taking exactly the same risk.

 

Hey adaycj - I see your point. One of us may be a 1/2 quart low or one of us may be a 1/2 quart high - in either case we should both be safe. 1/2 quart in either direction "should not" harm any modern engine. Though having the dipstick match the recommended oil requirement would make things easier for us owners...but would give us one less thing to discuss on this forum. Also, I understand your point concerning fleet vehicles now; can't have customers coming back saying that the oil level is incorrect when the only basis they have to check is with the dipstick. That could become a credability issue for your work. Thanks for the banter...I always enjoy a good debate (and learning something new.)

 

Because of our conversation here I paid particular attention to 4 oil changes on the same truck with the same engine. Three of the four even have consecutive VINs. As usual we filled them all to the full mark. The oil level varied by 1/2 quart and I paid extra attention to the exact amount needed. They weren't off by "exactly" one amount. The only thing that stinks about this is that I run into engines all the time that do not take the specified amount of oil. But how do you really know when the problem is just tolerances and not enough to do damage? Is it a quart or more? I couldn't imagine trying to make a warranty claim on this.

I can say from experience with a few customers that refuse to check their oil and have burned up engines as a result that 5 quart engines can run a bit less than 2 quarts low before trouble. 6.5 and 7 quart engines seem to be able to go almost 3. The evidence is shaky however. There is the point under operation where there is fast damage with low oil. Many have seen it. But in my Jeep I don't want even slow damage.

One last contribution. I have a motorcycle. It uses a wet sump like a Jeep and it has a sight glass you can use to check the level. If I fill it to the top of the glass it uses oil at high rpm. If I keep it full it will burn as much as a quart in 2000 miles (not that bad). If I keep it at 1/2 way up the glass it doesn't burn a drop. Full on the glass is a bit over the fill spec when I change it. I guess I am a hypocrite, I run that one at the spec, not full on the glass. At least it is still in the safe range.

Now what I think we need is a universal dipstick. It needs an adjustable rubber expanding plug at the handle end to seal well. And a nice "old school" matte steel finish so we can read it. You can cut it to fit and use a hardware store engraver to mark it. As the original post stated, the stock dipstick really does stink no matter what oil level you are trying to read.

 

i just run six quarts because i can go to walmart and buy one five quart jug of mobil one and one single quart jug of mobile one... come home, drain it all out, change the filter, and dump in six full quarts like DC calls for and call it a day. i never even have to check the dipstick.... luckily however, when i do, the six quarts shows up as full on the dipstick. my theory is thats good enough... if not and the motor burns up, then i'll drop in a HEMI and if that happens, i'll pay more attention to fill levels on the hemi

 

I would like to post a possible issue with the many dipstick readings. I see another variable that may or may not affect the reading. Everyone here seems to have different lift kits installed. Some have compensated for the front dive by adding 3/4 lift to the front. Some have added 150 lb. bumpers. My question is this, "Could the variable angle of the (almost said car) vehicle be causing so many different readings on the dipstick? Is there a way to gather enough info to see if this affects the dipstick reading?

I'm kinda new here, and my jeep has not arrived yet so I may be all wrong. Just a thought for you to ponder.

 

since the creation of this post, i've been watching my oil levels and they seem fine. did the oil change the other day to check if my dipstick was faulty... 5.5 quarts in and it was 1/2 quart low... filled up 6 and it was just right.


maybe we should take a poll on who has faulty dipsticks? the percentage could enlighten us.

 

your probably best off just filling it to the dip stick's full mark whether it is incorrect or not..

Picture bringing in you warranteed Jeep in for a blown engine, the first thing they are going to do is pull the dipstick, if its higher than the full mark they are probably going ot blame it on a lubrication problem.. if its just right, they should end it there. Id rather the dipstick show to be right then have to somehow prove to Chrysler that you didnt overfill your engine with oil.

 

I see your point, but I would rather put in the amount stated in the manual, which is six quarts. If the afore mentioned engine still has oil in it, simply draining and measuring the amount that comes out will prove it is per the manual. I'd think you'd have a stronger claim with six quarts in than 5.5 or less.

 

"Picture bringing in you warranteed Jeep in for a blown engine, the first thing they are going to do is pull the dipstick, if its higher than the full mark they are probably going ot blame it on a lubrication problem.. if its just right, they should end it there. Id rather the dipstick show to be right then have to somehow prove to Chrysler that you didnt overfill your engine with oil."

Overfilling oil probably isn't going to cause an engine to "blow up" its just going to cause the crank seals to leak, maybe even valve covers. Every motor I've ever taken apart still had oil in all the galleries and oil sitting in little recessed areas in the top of the cylinder heads, not to mention oil that was basically clinging to the crankshaft, rods and the rest of the internals in the block. When you drain the oil hot there is still probably close to half a quart of oil in the engine so filling to the top of the fill line on the dipstick is the correct way, not just blindly dumping 6 quarts in.

I'm betting if you got 10 JK's together and measured the dipsticks they would all be within 1 mm because they are manufactured by robot stamping machines so I doubt there is any difference. Anyone who puts 6 quarts of oil in their JK is overfilling it. If you doubt me just ask a service advisor or better yet a tech at a Jeep dealer if they fill to the top of the fill line or they just stick the factory capacity in.

BTW, JKGirl had a leaking rear crank seal, maybe she knows something about this...

 

Agreed. I've been taught, better a little under than over. There is a bit of room in the safe area on the dipstick. There's no real reason for the level to go over that line, but at least one good one for it not to.