2012 E350 Start up Rattle
Out Of Control!!
Joined: Apr 2019
Posts: 11,923
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
Thank you for your field report, nice to read about the 600Mi range! 
You have rattle until 20w50 oil is circulated in winter.
Is this with pump solenoid connected or disconnected ?
What type of oil is this?
Have you tried a lower 5w50 ester oil instead ?
Are your VVT lock pins or or worned out?
You have rattle until 20w50 oil is circulated in winter.
Is this with pump solenoid connected or disconnected ?
What type of oil is this?
Have you tried a lower 5w50 ester oil instead ?
Are your VVT lock pins or or worned out?
Thread Starter
Member
Joined: Sep 2021
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E350 Sport
I have replaced 3 of the cam adjusters on this type engine so I know that sound. On this car I had one bad adjuster it has been replaced already so I do not have cam adjuster issues. To my old ears it sounds like timing chain rattle. Very fast light tapping that goes away as soon as oil pressure builds and stays gone in all conditions until the car is parked overnight again and it is back for a few seconds on start.
Other than the 5-40W synthetic and now the 20-50W synthetic I know of no other oils being used in this engine. When life slows down a little I can take the front of the engine apart and replace the timing chain and guides but I was hoping to avoid that, at least this engine does not have the balance shaft issue like the 2008 E350 had, I fixed one of those, had to pull the entire engine. Huge job but it purred after the repair.
Other than the 5-40W synthetic and now the 20-50W synthetic I know of no other oils being used in this engine. When life slows down a little I can take the front of the engine apart and replace the timing chain and guides but I was hoping to avoid that, at least this engine does not have the balance shaft issue like the 2008 E350 had, I fixed one of those, had to pull the entire engine. Huge job but it purred after the repair.
Out Of Control!!
Joined: Apr 2019
Posts: 11,923
Likes: 6,776
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
chain tensioners
I have replaced 3 of the cam adjusters on this type engine so I know that sound. On this car I had one bad adjuster it has been replaced already so I do not have cam adjuster issues. To my old ears it sounds like timing chain rattle. Very fast light tapping that goes away as soon as oil pressure builds and stays gone in all conditions until the car is parked overnight again and it is back for a few seconds on start.
Other than the 5-40W synthetic and now the 20-50W synthetic I know of no other oils being used in this engine. When life slows down a little I can take the front of the engine apart and replace the timing chain and guides but I was hoping to avoid that, at least this engine does not have the balance shaft issue like the 2008 E350 had, I fixed one of those, had to pull the entire engine. Huge job but it purred after the repair.
Other than the 5-40W synthetic and now the 20-50W synthetic I know of no other oils being used in this engine. When life slows down a little I can take the front of the engine apart and replace the timing chain and guides but I was hoping to avoid that, at least this engine does not have the balance shaft issue like the 2008 E350 had, I fixed one of those, had to pull the entire engine. Huge job but it purred after the repair.
FYI: these "shorter" timing chains are not known to stretch.
There is still an intermediate shaft but without balancing weights.
In all that's 4x chains: 3x timing chains + 1x pump chain
Last edited by CaliBenzDriver; Dec 10, 2024 at 08:59 PM.
Out Of Control!!
Joined: Apr 2019
Posts: 11,923
Likes: 6,776
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
8Cyl. NA
single extra long timing chain (#10: oil pp chain)
M276/8 chains look like this:
4x chains setup
One primary timing chain to intermediate shaft then two secondary chains to twin DOHC (+ oil pp chain)
Last edited by CaliBenzDriver; Dec 11, 2024 at 02:52 AM.
MBWorld Fanatic!
Joined: May 2012
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From: Pepper Pike Ohio
24 GLS580 '23 E450 4matic 12 E350 4Matic
Good points and I think we witnessed that first hand in these engines. On the engine side of the business we did see that Roller Lifters liked the thin weight oils. The rollers are small and thicker oils take longer to get inside and lubricate them. Hope we do not bump into an issue with the roller lifers failing due to our changes but quiet starts are a nice change for sure.
The other thing I thought about is the Chain Driven Oil Pump, I hope we are not adding to much load on that chain and tensioner. Every change always has another side to it so maybe the next oil change I will drop back to 15-40 and listen for any more start up rattle.
The other thing I thought about is the Chain Driven Oil Pump, I hope we are not adding to much load on that chain and tensioner. Every change always has another side to it so maybe the next oil change I will drop back to 15-40 and listen for any more start up rattle.
MBWorld Fanatic!
Joined: May 2012
Posts: 2,359
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From: Pepper Pike Ohio
24 GLS580 '23 E450 4matic 12 E350 4Matic
Follow up once more for those interested. As the mileage has increased I am getting noise on start up again. The car has maybe 3500 miles on it since the 20-50w oil install. The weather has changed, much colder now, morning start ups are maybe in the low 40* range.
I do not think the oil is failing at this low miles check. I suspect the thick oil does not like the cold starts.
I have also found the engine is not as responsive at first start. After temps start to come up it runs normally again. I believe in the cold weather the cams do not like the thicker oil weight and are not responding at first due to the thicker oil. I only notice this on the first 1-2 miles after a cold start.
The start up noise is still short but now maybe 10 seconds before it quiets. Before this oil was installed I had about 15 seconds of noise. Sorry, I still do not have an audio clip to share.
So was this a success to go with thicker oil. No, but it was much better in the summer months. We have taken two long trips in this car recently, 1,000 miles each time. MPG was very good, 28.5-31 MPG running 70-85 for most of the trip.
The range in these cars is amazing, nearly 600 miles on a tank and it still had some range left over. This car does have the optional extended range tank, not sure how many gallons that adds but I like it.
I do not think the oil is failing at this low miles check. I suspect the thick oil does not like the cold starts.
I have also found the engine is not as responsive at first start. After temps start to come up it runs normally again. I believe in the cold weather the cams do not like the thicker oil weight and are not responding at first due to the thicker oil. I only notice this on the first 1-2 miles after a cold start.
The start up noise is still short but now maybe 10 seconds before it quiets. Before this oil was installed I had about 15 seconds of noise. Sorry, I still do not have an audio clip to share.
So was this a success to go with thicker oil. No, but it was much better in the summer months. We have taken two long trips in this car recently, 1,000 miles each time. MPG was very good, 28.5-31 MPG running 70-85 for most of the trip.
The range in these cars is amazing, nearly 600 miles on a tank and it still had some range left over. This car does have the optional extended range tank, not sure how many gallons that adds but I like it.
