E350 Blue tec engines

Mark Hurst

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Hi,

Looking at a 2016 E350 with blue tec, just wondering if there are any problems with these engines and is the service more frequent and expensive?

Thanks Mark
 

fabes

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Diesel or Petrol

I presume the former, but just to check..
 
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Mark Hurst

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Yes Diesel
 

malcolm E53 AMG

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All the OM642 engine derivatives including the latest Bluetec seem reliable with very few issues reported on here and any that are are usually thermostat failures (sticking open) @ circa £200 to replace. The EU6 engine in the car you are looking at has a urea tank in the spare wheel well and injection pump to deliver the urea into the exhaust to reduce NOx the urea is topped up at every service at nominal cost

You will enjoy the V6 diesel it’s almost as refined a petrol

Hope this helps!
 
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Mark Hurst

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Thanks for reply, I will be doing around 20,000miles a year, and have read reports of major failure with the Bluetec system and very expensive to repair.

All the OM642 engine derivatives including the latest Bluetec seem reliable with very few issues reported on here and any that are are usually thermostat failures (sticking open) @ circa £200 to replace. The EU6 engine in the car you are looking at has a urea tank in the spare wheel well and injection pump to deliver the urea into the exhaust to reduce NOx the urea is topped up at every service at nominal cost

You will enjoy the V6 diesel it’s almost as refined a petrol

Hope this helps!
 

Headhurts

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Thanks for reply, I will be doing around 20,000miles a year, and have read reports of major failure with the Bluetec system and very expensive to repair.

I have a 2016 E350 and although I have no technical knowledge I do read the forums regularly and have seen no reports of failure with the Bluetec system.

There was a post somewhere about some failure in the USA regarding trucks or vans but I cannot remember exactly.

I would not worry too much they seem quite reliable but you will always find the odd post about problems.

Robin
 

malcolm E53 AMG

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Thanks for reply, I will be doing around 20,000miles a year, and have read reports of major failure with the Bluetec system and very expensive to repair.

Most of the problems relating to modern diesel engines relate to low mileage/short journey use so the type of motoring you intend using the car for will be ideal, hope the car is what you are looking for and you won’t regret buying it
 

Craiglxviii

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Don’t know what major failures you’re on about, there have been literally a handful reported region wide. It’s a well understood and reliable system.
 
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Mark Hurst

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Don’t know what major failures you’re on about, there have been literally a handful reported region wide. It’s a well understood and reliable system.

If you google these engines there are lots of reports of oil leaks caused by the system running at high temp.

I know you should not believe all you read, that is why I am asking on this forum.
 

Pathfinder

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Here's an interesting read on Blue Tecs from a link posted on the other forum.
http://www.stephensservice.com/bluetec-diesel-issuesproblems/ and below is a copy and paste from an article the owner/author of the web site has published

......"The Bluetec diesel has a exhaust driven turbocharger. That means the hot exhaust going out the tail pipe is also used to turn the turbocharger. It’s a very efficient way to produce extra power. But, it has a dark side. The exhaust temperature routinely runs at over 1200F.

When you shut the engine off, that heat literately destroys the engine oil. Even the very best synthetic diesel motor oil will breakdown & revert back to tar, at 600F.

If you read the Mercedes-Benz owners forums about the OM642 diesel engine, you will see hundreds of owners with long list of complaints. It does not need to be like this. The OM642 diesel is a good engine. If you change the oil every 5000 miles and use Redline 15W/40 Diesel oil, you will have far fewer problems. Change the engine Air Filters every 20,000 miles and it will greatly reduce Blow-by. Change the Oil Separator at the first sign of oil leaking from the Turbo. (We’ve seen owners that have wasted thousands of dollars trying to fix oil leaks that are caused by the Oil Separator.)

Owners think they must go to the dealer for service when their car is new. Dealers lead them to believe it is a warranty requirement. This is not true. The sooner a new car starts using better oil and more frequent oil changes, the fewer problems it will have. We’ve seen so many so called “experts” tell owners to follow the manufacture recommendations. This is a sure fire way to ruin the engine and end up outrageous repair bills. We can prove what we say with Mercedes-Benz own service bulletins."
 
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LostKiwi

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Here's an interesting read on Blue Tecs from a link posted on the other forum.
http://www.stephensservice.com/bluetec-diesel-issuesproblems/ and below is a copy and paste from an article the owner/author of the web site has published

......"The Bluetec diesel has a exhaust driven turbocharger. That means the hot exhaust going out the tail pipe is also used to turn the turbocharger. It’s a very efficient way to produce extra power. But, it has a dark side. The exhaust temperature routinely runs at over 1200F.

When you shut the engine off, that heat literately destroys the engine oil. Even the very best synthetic diesel motor oil will breakdown & revert back to tar, at 600F.

If you read the Mercedes-Benz owners forums about the OM642 diesel engine, you will see hundreds of owners with long list of complaints. It does not need to be like this. The OM642 diesel is a good engine. If you change the oil every 5000 miles and use Redline 15W/40 Diesel oil, you will have far fewer problems. Change the engine Air Filters every 20,000 miles and it will greatly reduce Blow-by. Change the Oil Separator at the first sign of oil leaking from the Turbo. (We’ve seen owners that have wasted thousands of dollars trying to fix oil leaks that are caused by the Oil Separator.)

Owners think they must go to the dealer for service when their car is new. Dealers lead them to believe it is a warranty requirement. This is not true. The sooner a new car starts using better oil and more frequent oil changes, the fewer problems it will have. We’ve seen so many so called “experts” tell owners to follow the manufacture recommendations. This is a sure fire way to ruin the engine and end up outrageous repair bills. We can prove what we say with Mercedes-Benz own service bulletins."
That quoted article is contradictory....
"Even the very best synthetic diesel motor oil will breakdown & revert back to tar, at 600F" followed by "If you change the oil every 5000 miles and use Redline 15W/40 Diesel oil, you will have far fewer problems." suggests that Redline doesn't have the same issues but in reality its just another synthetic oil so surely has the same issues. Also exhaust temperature does not equate to oil temperature. Modern turbochargers are generally water cooled so the oil running through them never exceeds the manufacturers design spec and shouldn't break down or 'revert to tar' (in actual fact when the oil gets that hot it generally forms granules of carbon as opposed to form tar).

Turbos run at very high temperatures in all turbo engines (petrol and diesel) so this is not a BlueTec issue. I have had my turbo on my Smart (petrol) glowing orange at night from the heat. Same with my old T5 when I had that and my Saab 9-3. The T5 went to 220k miles on the original turbo using normal oil change intervals and that was regularly caned because it was so much fun to do so! The Smart likewise is on 145k miles on the original turbo and as anyone who owns one will know that engine loves being driven hard. The Smart just completed another 500 mile run back from the South West of France sitting at 130km for over 5 hours - the fourth such run in 4 years.

Air filters do not prevent blow by. Blow by is a function of piston ring sealing. The only way air filters prevent blow by is by limiting ingress of corrosive objects (sand/dust etc) and hence limiting wear. This really isn't much of an issue in the UK (maybe more so in the Middle East and perhaps dusty parts of the US.

I suspect the individual who wrote that article has some kind of vested interest.

As mentioned previously - the OM642 is generally thought to be very strong and reliable and on this forum there are hardly 'hundreds of complaints' suggested in that article.
 

Pathfinder

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The individual claims on his web site to have 45 years as an MB tech with 25 working as a master tech in MB dealerships. ( I think he means detroys the engine oil sitting inside the turbo bearing). I still find his articles and opinions very interesting.
 
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LostKiwi

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The individual claims on his web site to have 45 years as an MB tech with 25 working as a master tech in MB dealerships. ( I think he means detroys the engine oil sitting inside the turbo bearing). I still find his articles and opinions very interesting.
Even so.... the Smart isn't a water cooled turbo and it manages just fine.
If some one rags the RS off a turbo and then shuts it down instantly then any turbo will have issues with the oil burning on the shaft (this is what makes the granules of carbon). Its not an MB issue - its an issue across any turbo engine and one reason watercooled turbos came about.
 

Pathfinder

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Some of the turbos I have replaced on Volvo, Scania, MAN etc. have done over 500,000 miles without ever coming off the engine block, some have failed at less than 100k. Always down to oil issues, hence my interest in the oil theories and opinions:geek:
 

LostKiwi

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The only turbos I've replaced (repaired in reality) have been down to seal failures. Never had one with a failed bearing though have seen one or two on other cars.
 

Pathfinder

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The seal failures is most likely due to them getting roasted and becoming brittle and breaking up !
 

LostKiwi

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The seal failures is most likely due to them getting roasted and becoming brittle and breaking up !
Or poor quality oil used by previous owners.

Again none of these are unique to the MB350 engine or Blue Tec in general.
 

Craiglxviii

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If you google these engines there are lots of reports of oil leaks caused by the system running at high temp.

I know you should not believe all you read, that is why I am asking on this forum.
I don’t need to google them. I get to see global warranty data and the faults due to SCR systems are minuscule.

There are lots of people claiming IMS issues on 911 996s too but it’s still below 1% of affected engines...
 
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