Coupe/Roadster
Sponsored by:
Sponsored by:

Where does the oil from sump tank go after shutting engine off?

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old 05-13-2024, 01:22 PM
  #1  
Junior Member
Thread Starter
 
Green_Hell's Avatar
 
Join Date: Apr 2024
Posts: 25
Received 13 Likes on 6 Posts
AMG GTR
Where does the oil from sump tank go after shutting engine off?

I am about to tackle the oil change on my 2018 GTR. The instructions are pretty clear that the remote tank must be drained within 3 minutes of shutting down the engine, after idling it for at least 30 seconds. So where does the engine oil drain to (or from where does it drain INTO the tank) after shutting the engine off? Is that other mysterious area not drainable? Just curious as I will be pumping out the oil from the tank shortly after shutting off to minimize the mess on my garage floor.
Old 05-13-2024, 05:40 PM
  #2  
Member
 
G. P's Avatar
 
Join Date: Mar 2020
Location: Northeast USA
Posts: 247
Received 130 Likes on 78 Posts
2020 AMG GTC
Originally Posted by Green_Hell
I am about to tackle the oil change on my 2018 GTR. The instructions are pretty clear that the remote tank must be drained within 3 minutes of shutting down the engine, after idling it for at least 30 seconds. So where does the engine oil drain to (or from where does it drain INTO the tank) after shutting the engine off? Is that other mysterious area not drainable? Just curious as I will be pumping out the oil from the tank shortly after shutting off to minimize the mess on my garage floor.

Yes, there are 2 drains. One from the tank and the other from the engine oil pan. Of course there is some oil accumulated in the oil filter as well.

This video should shade some more light on the process.



There is some more info in this thread: 2020 AMG GT R Pro - MBWorld.org Forums

Good luck

Last edited by G. P; 05-13-2024 at 06:11 PM.
Old 05-14-2024, 06:43 AM
  #3  
Super Member
 
Stenzel-Germany's Avatar
 
Join Date: Dec 2020
Location: Germany
Posts: 539
Received 443 Likes on 237 Posts
AMG GTR
Hi,

The oil can flow back into the engine because the oil tank level is higher.
For this reason, the oil level should be checked within 3 minutes of switching off the engine. (Always check with oil at operating temperature)

According to regulations:
When changing the oil, it is not enough to just let it run for 3 minutes. The oil should be at 100°C. The background is the oil thermostat must be open.
The oil should therefore be drained via the drain plug (filler cap closed) within 3 minutes. This generates a negative pressure through which the oil lines are then "sucked out".

Then drain the engine block oil sump. Then change the oil filter. If you do everything according to the instructions you will have to refill about 7 liters of oil.

This doesn't work when vacuuming the oil tank.

In my experience the difference is about 0.5 liters.

My opinion:
First Engine filling is 9 liters. This means: even if the oil is changed as directed, 2 liters of old oil remain in the engine.
Whether 2 or 2.5 liters remain in the engine shouldn't make a big difference.

My oil change looks like this (no claim to the best solution):

Basically I change every 5000km. (Religion? :-))

Take a good branded fully synthetic oil 0W-40 and a branded Longlive oil filter (finer white filter fleece)
personally don't care about Mercedes approval. The costs are low if you do it yourself. (here, only approx. 5% of the gasoline costs)

The motor doesn't need to be at 100 °C either. A short trip until the oil temperature reaches approx. 80°C is enough.
Vacuum oil tank. (It's simply a cleaner solution :-)) Then remove both drain plugs and let it drain completely. (I'm not concerned here with the quantity, rather with residues, and that's more for the conscience)
Remove the oil filter and visually check the slats for residue. (Also more for your conscience)

After sealing, I fill in 6 liters. Then let the engine run until the oil is at least 80° C. (It's quick since the engine is warm)
Then fill it up to the maximum level.

Info:
At nominal speed, the oil pump delivers approx. 250L/min at 4 bar.
20sec. at idle, all the oil goes through once.

Best regards

Stenzel
The following 3 users liked this post by Stenzel-Germany:
G. P (05-14-2024), Green_Hell (05-15-2024), GTConn (05-15-2024)
Old 05-15-2024, 06:35 AM
  #4  
Junior Member
 
speadracer08's Avatar
 
Join Date: Jun 2020
Posts: 36
Likes: 0
Received 8 Likes on 6 Posts
AMG GT-C Roadster
Thank you Stenzel, it's always good to read a refresher course before going to my local (favorite) technician to change the oil.
Old 05-15-2024, 09:48 AM
  #5  
Junior Member
Thread Starter
 
Green_Hell's Avatar
 
Join Date: Apr 2024
Posts: 25
Received 13 Likes on 6 Posts
AMG GTR
Originally Posted by Stenzel-Germany
Hi,

The oil can flow back into the engine because the oil tank level is higher.
For this reason, the oil level should be checked within 3 minutes of switching off the engine. (Always check with oil at operating temperature)

According to regulations:
When changing the oil, it is not enough to just let it run for 3 minutes. The oil should be at 100°C. The background is the oil thermostat must be open.
The oil should therefore be drained via the drain plug (filler cap closed) within 3 minutes. This generates a negative pressure through which the oil lines are then "sucked out".

Then drain the engine block oil sump. Then change the oil filter. If you do everything according to the instructions you will have to refill about 7 liters of oil.

This doesn't work when vacuuming the oil tank.

In my experience the difference is about 0.5 liters.

My opinion:
First Engine filling is 9 liters. This means: even if the oil is changed as directed, 2 liters of old oil remain in the engine.
Whether 2 or 2.5 liters remain in the engine shouldn't make a big difference.

My oil change looks like this (no claim to the best solution):

Basically I change every 5000km. (Religion? :-))

Take a good branded fully synthetic oil 0W-40 and a branded Longlive oil filter (finer white filter fleece)
personally don't care about Mercedes approval. The costs are low if you do it yourself. (here, only approx. 5% of the gasoline costs)

The motor doesn't need to be at 100 °C either. A short trip until the oil temperature reaches approx. 80°C is enough.
Vacuum oil tank. (It's simply a cleaner solution :-)) Then remove both drain plugs and let it drain completely. (I'm not concerned here with the quantity, rather with residues, and that's more for the conscience)
Remove the oil filter and visually check the slats for residue. (Also more for your conscience)

After sealing, I fill in 6 liters. Then let the engine run until the oil is at least 80° C. (It's quick since the engine is warm)
Then fill it up to the maximum level.

Info:
At nominal speed, the oil pump delivers approx. 250L/min at 4 bar.
20sec. at idle, all the oil goes through once.

Best regards

Stenzel
This information is GOLD, as it is backed up by experience. I would rather keep some of the "old" oil and change oil more frequently vs. the mess the Mercedes process entails. I measure all fluids coming out or any of my cars and reference it for a refill. I will be using Stenzel's method on my next and periodic oil changes before my next track event. A wholehearted THANK YOU to Stenzel!

Last edited by Green_Hell; 05-15-2024 at 09:52 AM. Reason: grammar
Old 05-15-2024, 11:38 AM
  #6  
Super Member
 
user33's Avatar
 
Join Date: Dec 2013
Posts: 867
Received 378 Likes on 243 Posts
*
Originally Posted by Green_Hell
This information is GOLD, ... I will be using Stenzel's method on my next and periodic oil changes before my next track event. A wholehearted THANK YOU to Stenzel!
Agreed. FWIW, after each track day I consider the max oil temp reached and, based upon that (and the number of track days), optionally suck out 5+ liters of oil and refresh with new. The filter is always very clean when changed so I don't worry about that (other than yearly at <1/2 mileage interval changes), but I do want to maintain the additives in the "synthetic" oil. Somewhere I read that, at about 130 deg C (266 deg F), the oil additives start to rapidly deteriorate so I consider temps over 125 deg C vs time at those temps when deciding whether to replenish.
Old 05-15-2024, 02:09 PM
  #7  
Junior Member
Thread Starter
 
Green_Hell's Avatar
 
Join Date: Apr 2024
Posts: 25
Received 13 Likes on 6 Posts
AMG GTR
Originally Posted by user33
Agreed. FWIW, after each track day I consider the max oil temp reached and, based upon that (and the number of track days), optionally suck out 5+ liters of oil and refresh with new. The filter is always very clean when changed so I don't worry about that (other than yearly at <1/2 mileage interval changes), but I do want to maintain the additives in the "synthetic" oil. Somewhere I read that, at about 130 deg C (266 deg F), the oil additives start to rapidly deteriorate so I consider temps over 125 deg C vs time at those temps when deciding whether to replenish.
Excellent point. Not that this is critical, but I do buy my oils and consumables from FCP Euro and I am happy to report that I have used their "Lifetime Replacement" for all of my cars on oils, transmission fluids, filters, spark plugs, coil packs, brake fluid, brake pads, rotors, etc. I track my cars and I change fluids more often than most - the FCP Euro replacement policy just helps me get my butt in gear to do it. Works like a charm!

I have no affiliation to FCP Euro other than being a satisfied customer!
Old 05-19-2024, 02:43 PM
  #8  
Junior Member
 
Wasserott's Avatar
 
Join Date: Jun 2021
Location: Owasso (Tulsa) OK
Posts: 43
Received 21 Likes on 16 Posts
AMG GTR, GT350, Raptor, X6
I'd be interested in seeing what tools you guys use to vacuum out the oil. I've done the Mercedes procedure multiple times and it's dreadful!!!

Chuck

Old 05-20-2024, 03:18 AM
  #9  
Super Member
 
Stenzel-Germany's Avatar
 
Join Date: Dec 2020
Location: Germany
Posts: 539
Received 443 Likes on 237 Posts
AMG GTR
Hi,

I use this (Slightly modified, image is from the internet)

Best regards

Stenzel


The following users liked this post:
Wasserott (05-20-2024)
Old 05-20-2024, 06:35 AM
  #10  
Out Of Control!!

 
chassis's Avatar
 
Join Date: Sep 2018
Location: unbegrenzt
Posts: 13,316
Received 3,922 Likes on 3,088 Posts
2017 GLE350 4MATIC
Is an engine assembly photo or diagram available? This would clarify the drain plug vs tank locations. 20%+ stranded oil, because of sump design, seems high.
Old 05-20-2024, 09:51 AM
  #11  
Junior Member
 
Wasserott's Avatar
 
Join Date: Jun 2021
Location: Owasso (Tulsa) OK
Posts: 43
Received 21 Likes on 16 Posts
AMG GTR, GT350, Raptor, X6
That is pretty substantial to avoid the mess...anyone have other tools they want to share?
Old 05-20-2024, 01:47 PM
  #12  
Junior Member
 
det000's Avatar
 
Join Date: May 2021
Posts: 33
Received 30 Likes on 14 Posts
2020 AMG GT R
I haven't used my Mityvac specifically for oil changes on my GTR but it's worked well with my other cars. Should work for this.

Amazon Amazon
The following 2 users liked this post by det000:
user33 (05-20-2024), Wasserott (05-20-2024)
Old 05-20-2024, 02:37 PM
  #13  
Junior Member
Thread Starter
 
Green_Hell's Avatar
 
Join Date: Apr 2024
Posts: 25
Received 13 Likes on 6 Posts
AMG GTR
Quick update: Vacuumed 5 liters from the tank with car warm. Took about 7 minutes. Afterwards, when I opened the tank drain, a few milliliters came out and were collected. Then I proceeded to drain the engine oil pan, drained the filter (yes, drained the filter through the hex drain plug), removed the filter. Collected an additional 1.5 liters. put everything back and refilled with exactly 6.5 liters. Drove the car, measured the oil and it was dead nuts in the middle of the dipstick. Minimum splashing or spilling and a happy motor afterwards!
The following 3 users liked this post by Green_Hell:
G. P (05-20-2024), GTConn (05-21-2024), Wasserott (05-20-2024)
Old 05-21-2024, 10:50 AM
  #14  
Member
 
GTConn's Avatar
 
Join Date: May 2023
Posts: 206
Received 101 Likes on 67 Posts
2019 AMG GTC Solar Beam Yellow
I'm really liking this idea!

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: Where does the oil from sump tank go after shutting engine off?



All times are GMT -4. The time now is 08:06 PM.