GL350: Consistent high Iron reading in oil analysis
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Joined: Nov 2007
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Beaters 'til they die
GL350: Consistent high Iron reading in oil analysis
My 2015 GL350 has about 33,000 miles on it now and in concerned about longevity with the recommended MB Mobil 1 oil. I've had Blackstone tests run a few times now and the Iron readings are super high, 185ppm, at a 7k oil change interval. For comparison, my BMW gasser with 100% more miles between oil changes on BMW-spec weight Mobil 1 comes in at 14ppm.
I figured the Iron reading might drop as the motor was breaking in, but it's not happening. I'm starting to worry that the timing chain, timing sprockets, or piston rings are wearing terribly. The Blackstone tech literally asked if the engine was running normally given the several standard of orders of magnitude higher Iron wear reading in my samples as compared to hundreds of other OM642 oil samples (universal average for this motor is 46ppm).
Time to sell it? I'd hate to as we really like the car, but I don't like what I am seeing.
This might be our first and last MB.
I figured the Iron reading might drop as the motor was breaking in, but it's not happening. I'm starting to worry that the timing chain, timing sprockets, or piston rings are wearing terribly. The Blackstone tech literally asked if the engine was running normally given the several standard of orders of magnitude higher Iron wear reading in my samples as compared to hundreds of other OM642 oil samples (universal average for this motor is 46ppm).
Time to sell it? I'd hate to as we really like the car, but I don't like what I am seeing.
This might be our first and last MB.
Super Member
Joined: Feb 2017
Posts: 506
Likes: 54
GL350 Bluetec and GLS580
Check the Diesel forum on this site for a better response.
My 2015 GL350 has about 33,000 miles on it now and in concerned about longevity with the recommended MB Mobil 1 oil. I've had Blackstone tests run a few times now and the Iron readings are super high, 185ppm, at a 7k oil change interval. For comparison, my BMW gasser with 100% more miles between oil changes on BMW-spec weight Mobil 1 comes in at 14ppm.
I figured the Iron reading might drop as the motor was breaking in, but it's not happening. I'm starting to worry that the timing chain, timing sprockets, or piston rings are wearing terribly. The Blackstone tech literally asked if the engine was running normally given the several standard of orders of magnitude higher Iron wear reading in my samples as compared to hundreds of other OM642 oil samples (universal average for this motor is 46ppm).
Time to sell it? I'd hate to as we really like the car, but I don't like what I am seeing.
This might be our first and last MB.
I figured the Iron reading might drop as the motor was breaking in, but it's not happening. I'm starting to worry that the timing chain, timing sprockets, or piston rings are wearing terribly. The Blackstone tech literally asked if the engine was running normally given the several standard of orders of magnitude higher Iron wear reading in my samples as compared to hundreds of other OM642 oil samples (universal average for this motor is 46ppm).
Time to sell it? I'd hate to as we really like the car, but I don't like what I am seeing.
This might be our first and last MB.
Newbie
Joined: Mar 2020
Posts: 1
Likes: 0
2009 Mercedes E350, base
My 2015 GL350 has about 33,000 miles on it now and in concerned about longevity with the recommended MB Mobil 1 oil. I've had Blackstone tests run a few times now and the Iron readings are super high, 185ppm, at a 7k oil change interval. For comparison, my BMW gasser with 100% more miles between oil changes on BMW-spec weight Mobil 1 comes in at 14ppm.
I figured the Iron reading might drop as the motor was breaking in, but it's not happening. I'm starting to worry that the timing chain, timing sprockets, or piston rings are wearing terribly. The Blackstone tech literally asked if the engine was running normally given the several standard of orders of magnitude higher Iron wear reading in my samples as compared to hundreds of other OM642 oil samples (universal average for this motor is 46ppm).
Time to sell it? I'd hate to as we really like the car, but I don't like what I am seeing.
This might be our first and last MB.
I figured the Iron reading might drop as the motor was breaking in, but it's not happening. I'm starting to worry that the timing chain, timing sprockets, or piston rings are wearing terribly. The Blackstone tech literally asked if the engine was running normally given the several standard of orders of magnitude higher Iron wear reading in my samples as compared to hundreds of other OM642 oil samples (universal average for this motor is 46ppm).
Time to sell it? I'd hate to as we really like the car, but I don't like what I am seeing.
This might be our first and last MB.
I have the same problem with my 2009 E350. It's an M272 E35 engine with 137k miles. I bought a car with about 126k 1.5 years ago and doing oil tests since than. Also in Blackstone labs. I changed Mobil 1 0W-40 oil after 4k, 2k, 3k, no difference. Tests show 5-7 times higher content of iron.
When I've bought the car I've replaced all filters, liquids and spark plugs. The car has been driving fine, no smoke, hesitation, vibrations.
There was an oil leak from an oil drip pan cover (272 010 06 31) - a common problem. As the leak was small - I never had to add oil between changes and I stupidly neglected it. Last time I changed oil in Feb 2021 I put a magnetic oil drain plug hoping that it will gather iron from oil. After a week from oil change I've got a permanent misfire on cylinder 5 without any notice, just boom, check engine light and vibrations. Only two codes appeared 0629 - misfiring & 0653 - misfire in cylinder 5 causing catalyst damage. Replaced a spark plug, erased codes - all good, no misfire, no vibrations, no more codes, timings are good. The spark plug was NGK and I put it only a year ago (10k miles back) and it was oily. That puzzled me. Recent oil test shows nothing bad apart from high iron content.
I decided to replace oil drip pan with cover and hose going to the intake. Found oil there (see photos below). Cleaned everything from oil, put a new oil drip pan with cover.
Does anybody know what causes high iron content? And can anybody explain me why the spark plug was oily? It's hard to believe that oil got into cylinders through the intake in such quantities that the spark plug failed. And only in cylinder 5. Although I haven't checked other spark plugs. I should have seen smoke from exhaust, but there was nothing.
