How do experienced MB mechanics not know how to measure oil level? - Page 2 - PeachParts Mercedes-Benz Forum

pmckechnie · #16 07-12-2013, 08:54 AM

I would like to ask a few questions and tell some things I have learned about MB oil changes, and oil level.

First, which car are we talking about?

If you took your own oil, how much did you take?

I am in no way defending the mechanic as he should know better than think you brought what you wanted put in the car. If you took 9 quarts and he put it in then it was probably just a simple mistake.

Something I learned about my 500SEL is that if you drain the oil, put the plug back in and then change the filter, it will be way over full. The filter does not drain until the top is taken off. Another simple mistake for people not familiar with canister type oil filters.

The oil level will be highest when the engine is HOT and has set for about 5 to 10 min depending on the weight of the oil. If it is higher when cold, then you may have some drain back holes plugged up in the heads.

When you check the oil, if you pull the stick, clean it off, put it back in and pull it back out quickly, the level will be lower then if you leave the stick in for 10 seconds and then pull it back out. My theory on this is the dip stick handle has an o-ring on it. It makes the handle like a plunger in a pump and pushes the oil down in the dip stick tube. If you leave it in for 10 seconds or so, the oil level in the tube will come back up to the actual level in the oil pan. I don't know if this is true for all MBs but is for my 500 and 300D. If you don't believe me, try it some time.

Just my $.02 worth, that is not worth anything.

Paul

clacker · #17 07-12-2013, 09:01 AM

I worked in some Mercedes shops, dealerships etc. Most of the time, the tech did not have the engine oil hot when he changed it, was rushed and probably only got 6 quarts out, then promptly refilled with the "normal" billing amount, this results in an overfilled crankcase. Few if any EVER check the oil after running the engine and parking it, believe me. They check it as they are adding it. I used to find my Dads car way over full when picking it up, and the answer was it will leak and burn it off shortly anyways, we are helping protect the engine...and in some cases it was probably better off that way for owners who never open the hood (you can tell, the latches are seized up!)
It would be so easy and shocking for the service dept to check such simple things AFTER the tech is done with the car and they would reaslize how poor the quality of service really is (rather then washing the car or providing free coffee!) and looks for dirt/grease marks etc.
Things are not getting better in this area, only worse. Audi is trying to make a difference with new car service, but who wants a new car anymore? It will take a very long time to see any result and as staff turns around more frequently in the industry not likely to get better.

VA-Merc · #18 07-12-2013, 09:14 AM

I have always used the owner's manual method...and my results are different when checking on a warm engine than a cold. I always let it sit for about 10 minutes or so and then check it. My theory was maybe that some of the oil up in the filter housing settles down to the crankcase when it sits overnight resulting in the oil level appearing higher than it actually is. The owner's manual for both my 87 and my 83 give the same instruction of checking it when warm.

shertex · #19 07-12-2013, 09:19 AM

Quote:

Originally Posted by pmckechnie

I would like to ask a few questions and tell some things I have learned about MB oil changes, and oil level.

First, which car are we talking about?

If you took your own oil, how much did you take?

Paul

92 300D. Since it was in for a head gasket replacement, I provided extra oil (three one gallon jugs)....I wanted to make sure that they had more than they would need for a regular oil change.

funola · #20 07-12-2013, 09:22 AM

1. Why did you provide 9 qts?
2. Mechanic said he put in 8. Was there 1 qt left?

[QUOTE=shertex;3174497]Let's try it this way....if I drain the oil and replace the filter and then add EXACTLY the amount of oil specified for an oil change (in my case, 7.5 quarts), drive the car half an hour, park on a level surface, then measure the oil level after five minutes....IT WILL READ LOW. It will be between the two marks, but it will be a lower reading than you might expect. But, if I let it sit overnight (or for six hours or whatever), it will be close to or at the max mark.

Perhaps my mistake is assuming that there's something wrong with a cold oil level way above the max line. If that's the case, I'm happy to stand corrected.

Keep in mind that, for most purposes, the engine will be warm when people check the oil (service station, whatever). It's simply not practical for most people to wait a long time.

While it is true that the MB specification is to measure the oil when hot, you'll also notice that the ideal is for the oil level to be about halfway between the markings. See http://www.w124performance.com/service/Index/Resources/00.57EngineOilLevelSI.pdf I'm sure what happens is that a mechanic sees the oil halfway, mistakes "max" for "full," and adds oil.

In any event, it's certainly the case that, when you shut off the engine, the oil gradually drains into the pan. So there are a variety of levels when the engine oil is "warm."

EDIT: They claimed that they put in 8 quarts of oil (which is a little bit too much), but it looks like they used 9 (I provided the oil). I drained a full two quarts. When I get it back, I will get the level halfway between the marks WHEN WARM and then see what it looks like the next morning.[/QUOTE]

shertex · #21 07-12-2013, 09:25 AM

I will convert to MB method.

shertex · #22 07-12-2013, 09:36 AM

Quote:

Originally Posted by funola

1. Why did you provide 9 qts?
2. Mechanic said he put in 8. Was there 1 qt left?

I actually provided 12 quarts....it was in for a head gasket and I just wanted to make sure they had more than enough. 3 quarts leftover, so I assume they put in 9, though I suppose it's possible that some oil went some place other than in the engine.

shertex · #23 07-12-2013, 09:41 AM

FWIW, and if memory serves, I'm fairly confident that a halfway between the marks reading when warm would equate to a max mark reading (or close to it) when cold.

funola · #24 07-12-2013, 09:43 AM

Quote:

Originally Posted by shertex

I actually provided 12 quarts....it was in for a head gasket and I just wanted to make sure they had more than enough. 3 quarts leftover, so I assume they put in 9, though I suppose it's possible that some oil went some place other than in the engine.

Certainly a possibility. Did you provide a filter too? Maybe he kept that also? That'd explain the hi level.

shertex · #25 07-12-2013, 10:03 AM

Quote:

Originally Posted by funola

Certainly a possibility. Did you provide a filter too? Maybe he kept that also? That'd explain the hi level.

No...he provided and changed the filter.

Doktor Bert · #26 07-12-2013, 10:06 AM

On my 1978 300SD, when I change the oil, it takes 8 quarts to reach the full mark and it will stay right there until the temps get to 200°F and then the oil cooler fills and the level drops 1 quart.

If I check it cold in the morning, the level will be one pint higher than when hot....

JB3 · #27 07-12-2013, 10:25 AM

Quote:

Originally Posted by shertex

92 300D. Since it was in for a head gasket replacement, I provided extra oil (three one gallon jugs)....I wanted to make sure that they had more than they would need for a regular oil change.

are you satisfied with the head gasket job? Apart from the oil issue, would you recommend the place for older diesels?

where did you take it?

funola · #28 07-12-2013, 11:00 AM

Quote:

Originally Posted by Doktor Bert

On my 1978 300SD, when I change the oil, it takes 8 quarts to reach the full mark and it will stay right there until the temps get to 200°F and then the oil cooler fills and the level drops 1 quart.

If I check it cold in the morning, the level will be one pint higher than when hot....

Does the oil cooler drain itself or do you take extra steps?

shertex · #29 07-12-2013, 11:01 AM

Quote:

Originally Posted by JB3

are you satisfied with the head gasket job? Apart from the oil issue, would you recommend the place for older diesels?

where did you take it?

Took it to Fred's ******** in Warwick. I think, at the end of the day, Fred did a fine job. However, I was frustrated by inattention to detail at a number of points. Missing bolts, a coolant leak, firewall not connected to upper radiator support, etc.... So I sent it back and he's personally attending to everything....I pick it up next Wednesday.

In my experience, Fred is a very competent and knowledgeable tech and really knows his way around older diesels. HOWEVER, the guys he has working for him are sometimes a little sloppy. Fred is honest and will always make things right....but you may have to take the car back to him to get everything perfect.

My first choice would have been RDM in Tiverton. But Ray indicated he's not overly enthusiastic about doing head gaskets....and he doesn't take credit cards. So I took it to Fred....in retrospect, I wish I had taken it to RDM, even though I think I'll make out OK. I remain convinced the RDM is the best place for Mercedes in the state of RI.

I have also had reconfirmed my conviction that the best shops are those that have no employees....one guy and only one guy does all the work.

shertex · #30 07-12-2013, 11:06 AM

This thread got me curious....went out to check the 91 300D. Level surface, perfectly cold engine, oil measured 0.6 on dipstick. Drove the car a bit, got it up to operating temperature (although I of course don't know the oil temp), shut it off, waited 10 minutes, then measured. Was at 0.4 on dipstick.

Next I'll try it after a long run, when everything is good 'n' hot.