BimmerFan52

First, YOUR CAR'S ENGINE WAS FILLED WITH SYNTHETIC MOTOR OIL AT THE BMW FACTORY before testing and shipment. ALL BMWs since probably MY2000 (and likely before) were filled with synthetic motor oil. Exactly which brand of synthetic oil is not important. Auto manufacturers typically use at least two or three equivalent sources for lubricants as they can't afford for the production line to stop if the production of a single source lubricant was interrupted and the competition between lubricant suppliers keeps cost down. Likely suppliers are Castrol GmbH, Motul, Shell GmbH or Pentosin GmbH. But it doesn't matter as long as they are synthetic oils in a certain viscosity range. You would lose your bet - this is NOT the first time the engine has seen synthetic motor oil.

Second, you say your car's oil was changed at "various locations" and you "assume" Castrol oil was used. If you took your car to ANY quick lube place and paid for their regular oil change I can guarantee they used their "buy it by the barrel" cheap petroleum based motor oil. The Castrol oil specified on the oil filler cap is synthetic oil. Luckily for you, if you keep your oil drain intervals reasonable ANY good quality name brand oil (with a GF-5 rating and grade of 30 or higher) you use today, whether it be group II (petroleum based oil), group III (petroleum based heavily hydroprocessed oil or semi-synthetic) or Group IV (fully synthetic) will protect your engine.

The big advantages of synthetic are excellent flow at sub-zero ambient temperature starts coupled with ability to withstand heat without losing viscosity and the breakdown of contaminants in Dino oil (such as paraffins or waxes) that can coat engine parts.

By not specifying synthetic motor oil of ANY brand when you got your oil changed you, and possibly the previous owner, got the engine gaskets used to Dino oil. Again, there is nothing inherently wrong with Dino oil if drain intervals are short, but you deviated from the FACTORY SPECIFIED engine oil. The gaskets and seals have grown used to Dino oil and its different characteristics.

Third, Tyler at Mobil, while likely a pleasant fellow, is a phone operator who reads from a script. He obviously knows nothing about what type of oil was used to fill the car when new. If he did he would have pointed out to you that you have been using petroleum oil CONTRARY TO MANUFACTURER'S SPECIFICATIONS. BMW provides a list of approved synthetic motor oils they recognize as having the characteristics required to protect your engine. There are no Dino oils on the list.

The choice of which type of oil to use, petroleum based or synthetic is yours. But if you deviate from the manufacturer's recommendation for oil and then something goes wrong it is not Mobil's responsibility to correct your mistake. And if you had a dollar for every valve cover gasket that has leaked on a BMW E60 you could easily go out and replace your 525 with a brand new M5. It is one of the most common leaks, even for people who have followed the factory recommendation and used synthetic motor oil from day one. BMWs are known to leak like the residents of an old-folks home.

IMHO you need to first decide if you want to go back to Dino oil or stay with synthetic.

If you decide to stay with synthetic I would switch immediately to a specified high-mileage synthetic that is a heavier grade (40 or 50) and which has extra gasket swell additives.

If you decide to go back to Dino oil I would still seek out a specified high-mileage oil.

Then wait to see if the leaking stops. If not get the gasket replaced. Then stay with the same oil consistently. DO NOT jump from oil to oil. If you choose a Dino oil I would change it every 3K miles. If a synthetic oil I would recommend 6K drain intervals.

seanjordan20

Ok, "Bill Nye the Science Guy" . We are merely giving suggestions and the suggestion is to change back to see if it makes a difference.

BimmerFan52

+1
I thought I agreed with you, no? I also suggested that he either try switching back to Dino oil or try high-mileage higher grade synthetic at the end of my previous post.

Sorry if I used big words.
Just trying to educate the noobs such as the OP.

And incidentally, that really hurts to be compared to that liberal douche bag Bill Nye.

seanjordan20

Sorry. It wasnt meant directly towards you it was the thesis you wrote. It just made me laugh so I had to say something I thought was funny. LOL. I got what you were saying but he might not of.

twh

Now wait a minute. Bill Nye is a reasonable person and believes in facts and science as it seems you do also.

knklhead

Wow, I didn't realize how much excitement I'd cause even at the suggestion that Mobil 1 0W-40 could cause weeping at the valve cover gaskets. Interesting that on one hand, many say it can .. yet others like to take the opportunity to beat people up. I'm not posting to p*ss on anyone here. And calling me a "noob" because I changed my own oil based on recommendations that this oil WAS recommended and okay for my car?

Bottom line seems pretty straight forward to me, so far. If you have a higher mileage BMW and are thinking of using Mobil 1 0W-40 on your BMW -- don't. How's that? Did I upset anyone with that statement?

Now, having said that, seems to me there's reason to believe that switching BACK to Castrol/BMW 5W-30 might stop the leak. I'd be okay with that, too.

On Bill Nye -- yeah, never trust a scientist who agrees with 99% of all other scientists. You know they must be up to something ...

BimmerFan52

HaHa. Yes I did do a bit of bloviating in my thesis. Hope I got a passing grade!

Early on when I was a noob I always appreciated the more knowledgeable members who didn't just state the facts, but spent the time to tell how something worked or layout a step by step method of repair, along with tips and tricks.

Short of gas there is nothing we put in our cars more often than oil, and choosing correctly is important to the life of the engine.

You are right that if the OP just goes into a Jiffy-Lube and says "change my oil" then I am likely wasting my time discussing hydrodynamic films.

BimmerFan52

Excitement. .... No.

First, "noob" or newbie is not a derogatory term. It simply means a person who is new to car maintenance, or new to a certain area of car maintenance.

Your posts suggests that you didn't know what oil the previous owner used, and that you were unsure what oil you use. Your quote: "prior to me changing the oil it was done at various locations -- I assume Castrol, since that's printed on the filler cap". I read "various locations" and your assumption of what oil was used to mean you were going to quick lube places. If by various location you mean various dealers then yes you can assume they used synthetic.

If you have been using BMW/Castrol synthetic all along then the chances that the leak was caused by switching to Mobil 1 0W-40 is INFINITESIMAL. The two oils are very similar.

Upset? Hardly. I have no vested interest in one oil over another. I strongly believe in changing oil while it is still rich in additives. and I have always maintained that the brand of oil is no where near as important as proper drain intervals.

My 545i has 120K miles on it, and I happen to use only Mobil 1 0W-40 because of its availability and price at Walmart (and it is on the BMW list of approved oils). I have the entire dealer service history of the previous owner for my car and he used only BMW/Castrol 5W-30. I have experienced no major leaks after ten drain intervals. But my history proves nothing. My car has not experienced the same history, same driving habits and same ambient temperatures that yours has.

Chase Mobil to seek reimbursement if you must, but it will likely be a Don Quixote mission in futility.

BimmerFan52

Years ago I used to enjoy Bill Nye and his science. But lately he has chosen to include politics in his act, and let's just say we definitely don't see eye to eye.

knklhead

"chosen to include politics in his act" I sense you mean he weighed in on global warming? Maybe you should write to him -- he's probably a global warming noob!