Are these oil leak problems related

2012 MERCEDES BENZ ML350
75,000 MILES • 6 CYL • AWD • AUTOMATIC
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CARLY PATEMAN
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I had an engine oil cooler seal leak in my car about a month ago. Mercedes covered the cost of the repair as it is a known issue with this year/make/model. Less than a month later, I notice more oil leaking from my car. Today they inform me that it is an oil filter housing leak, and that repair will not be covered under the warranty since the oil filter leak is unrelated to the engine oil cooler seal leak that I already had repaired under warranty.

I want to know if it is possible that the oil filter housing leak is in any way related to the major engine oil cooler seal leak that was covered under my warranty.

2012 Mercedes ML350 BT
Jan 9, 2017 at 11:46 AM
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CARADIODOC
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Nope. That is like saying the tire sprung a leak from driving over a nail, and that is related to the other tire blowing out a month ago from hitting a curb. The type of leak you are describing is common on any car, especially at the mileage you listed. The only difference is you have a relatively expensive car. It will develop the same problems as any other car, they are just more expensive to repair in most cases.

What you might look at is the oil you are using. When there is already a small leak, synthetic oil tends to turn it into a bigger leak a lot faster. If you recently switched to synthetic oil for the first time, switching back to the previous brand will often make the leak slow down or stop after a few months.

Switching brands of oil can also cause a leak to show up for the first time. All oils contain dispersants, detergents, anti-foaming agents, corrosion inhibitors, and seal conditioners. Those additives in one brand of oil may not be compatible with those in other brands. The detergent in the new brand could degrade the leftover seal conditioner in the old oil, and that could allow a seal to leak.

Those are just some things to think about. It is just as likely the filter housing gasket decided it was time to start leaking. It is a gasket, so we know it was going to do that sooner or later.
Jan 9, 2017 at 1:54 PM