High Oil Reading On Dipstick

[jimmy buoy]

Hi All,

I've got a peculiar issue with my newly purchased 2010 Genesis 3.8 Sedan. After purchasing, I checked the oil level (since the previous owner had gone to a quickie oil change place). It was VERY high on the dipstick, so I sucked about a litre or so from the engine with my extractor and ran the car for another 1000 Km's which was problem free.

I then completed my first oil change (I do my own work if possible) using the extractor to pull the hot oil through the dipstick tube. It started sucking air after taking out only a couple of litres. So, to be safe and know that ALL the oil was removed prior to refilling the engine with new oil I opened the engine oil drain under the engine. Another 2-3 litres of old oil came out so I guess draining the engine with the extractor isn't going to be an option for future oil changes. Not sure why...

After changing out the filter on the top of the engine and securing the drain plug below, I proceeded to fill the engine with 5.2 Litres of synthetic oil, started the car and let it run 30 seconds or so (the engine oil light stayed on for a few seconds then went out as the filter filled with oil) and checked the oil level on the dipstick. It was on the top dot - PERFECT.

Fast forward a few weeks, I decide to check the oil level BEFORE starting the car and see that the oil level is showing as WAY OVERFILLED again! WTF! I started the engine and let it run for 30 seconds, check again in 5 minutes and the oil level is on the top dot.

Any ideas as to what is happening here? I've always thought the best and most accurate reading will be after the vehicle sits for a long period of time so all the oil drains back into the crank case. I'm stumped. Here's some photos of the dipstick from the cold engine.

 

[Hueydriver]

Does the oil smell like gasoline?? Gas could be debuting the oil.

 

[TinsleyC]

I'm curious what the readings will be if you warm it up and check it every 10 minutes over an hour. Or every 5 minutes over half hour.

 

[pmckechnie]

Jimmy, My first guess is the oil filter is draining back when it sits for a while. I am not sure how it is done in a 2010 Genesis V6 (well not in any Genesis) to keep the oil in the filter when the engine is not running.
In some engines there is a check valve in the filter or in the oil pump. What brand filter did you use? Some brands don't bother to have a valve. It makes it fit different engines with out having more products.
Paul

 

[jimmy buoy]

Thanks for the replies so far guys.

1) The oil is only about two weeks old and it looks, smells, and feels like Mobil 1 should - definitely no gas or glycol.

2) I moved the car to a more level part of the driveway and have checked it every 10 minutes for 30 minutes and it's perfect at the top hole for now. My usual parking spot has a bit of a lean towards the driver's side (but not much). I plan on taking another look in a bit and again in the morning before starting the engine.

3) Regarding what brand of filter, I went to my local Hyundai Dealer who couldn't tell me what filter this model used - even with the VIN (hard to believe). He gave me three different possible filters and I matched it to the size and type of the old filter once removed and took the other two back. Both O-Rings were replaced - the large one on the plastic cap and the little one that fits on the end of the filter holder that extends into the engine. Hyundai Part # 26320 3C30A

It may be possible that the filter that was last used (that I copied with the new one) is not the correct one for this engine. It was an paper filter with paper ends that had to be firmly pressed onto the cap and engine fittings to install (didn't rip it though) and it had a plastic mesh interior probably for structural integrity. There was no signs of any one way valve on the filter. I'm not sure what the purpose is of the plastic tip with the little O-Ring is that extends downward into the engine. Even if there should be a check valve to prevent the contents of the filter to drain back into the engine, I can't see it holding more than about 1/2 a litre anyway which doesn't account for such a high reading on the dipstick.

It may also be possible that the dipstick had at some time been replaced and is the wrong one for this car engine?

 

[jimmy buoy]

Just went out and checked it again. It's about 1/4" above the top dot at this point. It's been about 3hrs now.

 

[TinsleyC]

Just went out and checked it again. It's about 1/4" above the top dot at this point. It's been about 3hrs now.

Sounds like oil in the upper part of the engine is draining down slowly.

So what if this happened: You warmed up the engine in prep for change the oil. For some reason your engine is holding oil up high in the engine. Blocked drain holes? You add the recommended amount of oil. Since some old oil is held elsewhere in the engine, it fills as expected. Then, over several hours, that held oil drains down and you now have too much oil.

Each time you check it 5-10 minutes after turning it off, it looks good. Each time you check it after 6 hours, it's too full.

If oil is not flowing it could be a bad thing.

Hey, just a guess!

It's a filter cartridge, right? Not a spin-on filter? I know the newer 3.8s are cartridges, just not sure of the older ones. There newer 3.8s have the filter at the bottom of the engine. Maybe they moved it for a reason.

 

[pmckechnie]

Jimmy, The following is just as a reference to what I expect to see on my 2018 G80 V6 when checking oil, I checked it this morning. 7/14/2020 at 10:00 A.M.. Outside temp is 80 deg f.
Car sitting overnight. Check oil and it was 1/8 inch overfull.
Started engine and let it run for about 2 min. Check again and it is now 1/8 inch below full.
I know from previous checks, it is exactly on the full mark when the engine is warmed up.

The next thing you need to do is find out exactly which filter you need, even if it involves calling Hyundai customer service. If it is different from the one you used, correct that problem first.

I still think the oil filter is draining down after setting overnight. And that could be caused by having the wrong filter.

Keep us informed.

Maybe someone else with a 2010 Hyundai Genesis V6 could check their oil after sitting over night and then again after being warmed up.

 

[jimmy buoy]

Ok guys, I took another reading before starting the car just now and with it sitting all night the oil level has not changed from last night. It's just about 1/4" over the full dot which is fine.

The only thing I can think of is that the normal parking spot for the car has what I would call a slight tilt towards the driver's side and that must be enough to cause the oil level reading to be that off. Strange.

I knew there was something that didn't add up when I recently changed the oil, totally draining the old oil from the drain plug then measuring 5.2 Ltrs of Mobil 1 and filling the crank case. The high oil reading just didn't make any sense - even with the oil filter area draining back to the crank case. And yes, TinsleyC - it is a cartridge oil filter very similar to the one on my 5.0.

Sorry for the false alarm and thanks to everyone who offered helpful suggestions!

 

[MOKS-Gen1]

I noticed high oil level on my recently bought/used 2009 4.6L. It was normal when I checked before test drive.

I did oil change and filter. Ran engine, checked 5 mins later and same, overfull. Then, I noticed the dipstick surface pointing to the fender, shows high. the surface of the stick facing the engine, it's perfect oil level, just at the top dot on the stick. I checked and rechecked several times. So, I get high oil reading on only one side of the stick. Weird. Been 2K since I changed oil, same observations o the stick. Glad mine's not using any oil in 2K.

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