Jun 10, 2015, 06:49 PM
Last edit by: IB Advertising
See related guides and technical advice from our community experts:
Browse all: Engine Diagnostics
- Mercedes-Benz C-Class: Why is My Engine Getting Carbon Buildup?
Guide to diagnose trouble and recommended solutions
Browse all: Engine Diagnostics
New DI Engines -- Excessive Carbon Buildup ??
MBWorld Fanatic!
Joined: Jun 2011
Posts: 2,400
Likes: 259
From: Canada
A car
Anyways, the evidence presented was enough to keep me from doing that (not the EGR in that case, but the PCV return)
MBWorld Fanatic!
Joined: Nov 2001
Posts: 5,851
Likes: 196
From: Huntington Beach, Ca.
'17 Jaguar XF
I've also read some articles about blanking the egr valve and seen before and after pictures that show less carbon buildup with it removed. First....without remapping the motor you'll use more gas without question and probably, not all cars, throw a CEL. Yes there is gas vapor in the crankcase but no where near the amount that passes the intake valve before it closes. That's why valve timing and piston crown changes (charge swirl) have such a big effect on the carbon buildup. I am neither an expert nor a scientist and don't claim to be.
MBWorld Fanatic!
Joined: Jun 2011
Posts: 2,400
Likes: 259
From: Canada
A car
I've also read some articles about blanking the egr valve and seen before and after pictures that show less carbon buildup with it removed. First....without remapping the motor you'll use more gas without question and probably, not all cars, throw a CEL. Yes there is gas vapor in the crankcase but no where near the amount that passes the intake valve before it closes. That's why valve timing and piston crown changes (charge swirl) have such a big effect on the carbon buildup. I am neither an expert nor a scientist and don't claim to be.
MBWorld Fanatic!
Joined: Nov 2001
Posts: 5,851
Likes: 196
From: Huntington Beach, Ca.
'17 Jaguar XF
EGR valves come into play at low rpms. It dilutes the intake charge with more air/crankcase vapor which leans it out. Removed it takes in more gas because the intake pressure is constant and takes in the same volume of charge....it just has less vapor/air without the EGR to feed it.
MBWorld Fanatic!
Joined: Jun 2011
Posts: 2,400
Likes: 259
From: Canada
A car
EGR valves come into play at low rpms. It dilutes the intake charge with more air/crankcase vapor which leans it out. Removed it takes in more gas because the intake pressure is constant and takes in the same volume of charge....it just has less vapor/air without the EGR to feed it.
Senior Member
Joined: Feb 2015
Posts: 435
Likes: 81
From: New Zealand
W204 C200, BMW E30 M3, 1980Gt Mini, Toyota Corona, KTM 200 EXC.
Just to clear up any confusion block off the EGR valve (exhaust gas recirculation) this is what lets burnt exhaust fumes back in too the intake system.
By blocking it up this stops the exhaust fumes going in to the intake and in my experience with petrol and especially diesels works very well in eliminating carbon build up. Most cases the engine runs noticably smoother at light throttle after this mod.
My experience is with Diesels, carb petrol and port injection petrol in all these case the engine did not need any sort of tuning/ mixture adjustment after blocking off the valve.
Do not block off the PCV valve you will be in serious trouble with oil leaks.
Yes there are EGR valves in Mercedes petrol engines this link is one example, and if you look carefully at a photo of used one you should see carbon build up.
https://www.google.co.nz/search?q=me...&bih=689&dpr=2
Last edited by NZ-Merc; May 10, 2017 at 09:01 AM.
MBWorld Fanatic!
Joined: Jun 2011
Posts: 2,400
Likes: 259
From: Canada
A car
Hi,
Just to clear up any confusion block off the EGR valve (exhaust gas recirculation) this is what lets burnt exhaust fumes back in too the intake system.
By blocking it up this stops the exhaust fumes going in to the intake and in my experience with petrol and especially diesels works very well in eliminating carbon build up.
My experience is with Diesels, carb petrol and port injection petrol in all these case the engine did not need any sort of tuning/ mixture adjustment.
Do not block off the PCV valve you will be in serious trouble with oil leaks.
Yes there are EGR valves in Mercedes petrol engines this link is one example.
https://www.google.co.nz/search?q=me...&bih=689&dpr=2
Just to clear up any confusion block off the EGR valve (exhaust gas recirculation) this is what lets burnt exhaust fumes back in too the intake system.
By blocking it up this stops the exhaust fumes going in to the intake and in my experience with petrol and especially diesels works very well in eliminating carbon build up.
My experience is with Diesels, carb petrol and port injection petrol in all these case the engine did not need any sort of tuning/ mixture adjustment.
Do not block off the PCV valve you will be in serious trouble with oil leaks.
Yes there are EGR valves in Mercedes petrol engines this link is one example.
https://www.google.co.nz/search?q=me...&bih=689&dpr=2
Anyways, for the Audi folks I used to chill/chat with, they just blocked the return back to the intake from the PCV valve.
Senior Member
Joined: Feb 2015
Posts: 435
Likes: 81
From: New Zealand
W204 C200, BMW E30 M3, 1980Gt Mini, Toyota Corona, KTM 200 EXC.
PCV valve is (positive crankcase ventilation valve) and this is the valve which allows the fumes from inside of the sump/engine and any gasses which pass the rings to be vented in to the intake manifold.
I can not recall the theory exactly at the moment I think there is a slight pressure difference between the intake and crankcase which is controlled by the valve with a seating ball and light spring.
I can not recall the theory exactly at the moment I think there is a slight pressure difference between the intake and crankcase which is controlled by the valve with a seating ball and light spring.
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
MBWorld Fanatic!
Joined: Jun 2011
Posts: 2,400
Likes: 259
From: Canada
A car
I probably went through 10 or so different ones on the A4. Did diddly poop
And PVC is for pipes in your house. I think you mean PCV
Member
Joined: Dec 2016
Posts: 147
Likes: 11
From: North of Charlotte NC
2015 C350 Sport
???
WRONG. Have run catchcan for years and have done analysis on them. They make ZERO measurable difference to intake valve buildup in DI engines.
I probably went through 10 or so different ones on the A4. Did diddly poop
And PVC is for pipes in your house. I think you mean PCV
I probably went through 10 or so different ones on the A4. Did diddly poop
And PVC is for pipes in your house. I think you mean PCV
Just giving you a hard time..........
MBWorld Fanatic!
Joined: Jun 2011
Posts: 2,400
Likes: 259
From: Canada
A car
MBWorld Fanatic!
Joined: Nov 2001
Posts: 5,851
Likes: 196
From: Huntington Beach, Ca.
'17 Jaguar XF
MBWorld Fanatic!
Joined: Jun 2011
Posts: 2,400
Likes: 259
From: Canada
A car
Oily watery goop. No it did not stop the carbon buildup. It's easy in my old car to take a look at the intake valve. All one needs is one screwdriver and a horoscope. I inspected them religiously across all 4 seasons every 5000km. there was no measurable difference.
MBWorld Fanatic!
Joined: Jun 2011
Posts: 2,400
Likes: 259
From: Canada
A car
Newbie
Joined: Feb 2018
Posts: 3
Likes: 0
c250 (2010)
Questions - DI C250 carbon buildup
Hi, new member here. Thank you to all who have shared their knowledge above - very interesting though a lot of it over my head.
I have a couple of questions, I'll keep it as succinct as possible. Though not mechanically knowledgeable, I have read through the thread and wanted to confirm my understandings. Apologies if I am asking stupid questions, that's why I am here - to learn.
2010 C250 CGI / 1.8L 4 cylinder turbo / direct injection / 150,000 km / Australia
-Car started "stuttering" under power repeatedly resulting in Check Engine Light and limp mode.
-MB Dealer diagnosed excessive carbon buildup in air intake manifold
-Intake manifold cleaned and one ignition coil replaced by MB Dealer. Car returned.
-Though much better the car still "stutters" under constant power as it did before.
-Car now booked into MB Dealer to resolve.
When the car was returned I asked specifically whether the air intake valves had been cleaned. MB Dealer replied "No, they did not need cleaning".
My question is this: If there is excessive carbon buildup in the air intake manifold would that not also mean there is excessive carbon buildup on the air intake valves, meaning they also need cleaning via walnut shells or otherwise? Or am I wrong?
I guess what I am wondering is - did this guy (MB Dealer) lie to me when they had done only half the required job.
Thanks in advance for your help. WilliamH
I have a couple of questions, I'll keep it as succinct as possible. Though not mechanically knowledgeable, I have read through the thread and wanted to confirm my understandings. Apologies if I am asking stupid questions, that's why I am here - to learn.
2010 C250 CGI / 1.8L 4 cylinder turbo / direct injection / 150,000 km / Australia
-Car started "stuttering" under power repeatedly resulting in Check Engine Light and limp mode.
-MB Dealer diagnosed excessive carbon buildup in air intake manifold
-Intake manifold cleaned and one ignition coil replaced by MB Dealer. Car returned.
-Though much better the car still "stutters" under constant power as it did before.
-Car now booked into MB Dealer to resolve.
When the car was returned I asked specifically whether the air intake valves had been cleaned. MB Dealer replied "No, they did not need cleaning".
My question is this: If there is excessive carbon buildup in the air intake manifold would that not also mean there is excessive carbon buildup on the air intake valves, meaning they also need cleaning via walnut shells or otherwise? Or am I wrong?
I guess what I am wondering is - did this guy (MB Dealer) lie to me when they had done only half the required job.
Thanks in advance for your help. WilliamH
MBWorld Fanatic!
Joined: Jun 2011
Posts: 2,400
Likes: 259
From: Canada
A car
Hi, new member here. Thank you to all who have shared their knowledge above - very interesting though a lot of it over my head.
I have a couple of questions, I'll keep it as succinct as possible. Though not mechanically knowledgeable, I have read through the thread and wanted to confirm my understandings. Apologies if I am asking stupid questions, that's why I am here - to learn.
2010 C250 CGI / 1.8L 4 cylinder turbo / direct injection / 150,000 km / Australia
-Car started "stuttering" under power repeatedly resulting in Check Engine Light and limp mode.
-MB Dealer diagnosed excessive carbon buildup in air intake manifold
-Intake manifold cleaned and one ignition coil replaced by MB Dealer. Car returned.
-Though much better the car still "stutters" under constant power as it did before.
-Car now booked into MB Dealer to resolve.
When the car was returned I asked specifically whether the air intake valves had been cleaned. MB Dealer replied "No, they did not need cleaning".
My question is this: If there is excessive carbon buildup in the air intake manifold would that not also mean there is excessive carbon buildup on the air intake valves, meaning they also need cleaning via walnut shells or otherwise? Or am I wrong?
I guess what I am wondering is - did this guy (MB Dealer) lie to me when they had done only half the required job.
Thanks in advance for your help. WilliamH
I have a couple of questions, I'll keep it as succinct as possible. Though not mechanically knowledgeable, I have read through the thread and wanted to confirm my understandings. Apologies if I am asking stupid questions, that's why I am here - to learn.
2010 C250 CGI / 1.8L 4 cylinder turbo / direct injection / 150,000 km / Australia
-Car started "stuttering" under power repeatedly resulting in Check Engine Light and limp mode.
-MB Dealer diagnosed excessive carbon buildup in air intake manifold
-Intake manifold cleaned and one ignition coil replaced by MB Dealer. Car returned.
-Though much better the car still "stutters" under constant power as it did before.
-Car now booked into MB Dealer to resolve.
When the car was returned I asked specifically whether the air intake valves had been cleaned. MB Dealer replied "No, they did not need cleaning".
My question is this: If there is excessive carbon buildup in the air intake manifold would that not also mean there is excessive carbon buildup on the air intake valves, meaning they also need cleaning via walnut shells or otherwise? Or am I wrong?
I guess what I am wondering is - did this guy (MB Dealer) lie to me when they had done only half the required job.
Thanks in advance for your help. WilliamH
Welcome to the forum. I don't think you'll get a lot of info from us on this thread because this thread is specifically talking about excessive carbon buildup on direct injected gasoline cars. I believe your cgi is a diesel, and thus most of us don't have any experience working with that. Hopefully someone else can chime in here. Personally, I'd start another thread instead of posting in this one if in fact your car is a diesel to get you the eyeballs necessary to help you resolve your issue.
MBWorld Fanatic!
Joined: Aug 2013
Posts: 1,364
Likes: 149
2012 C300 4MATIC Sport
Hi William
Welcome to the forum. I don't think you'll get a lot of info from us on this thread because this thread is specifically talking about excessive carbon buildup on direct injected gasoline cars. I believe your cgi is a diesel, and thus most of us don't have any experience working with that. Hopefully someone else can chime in here. Personally, I'd start another thread instead of posting in this one if in fact your car is a diesel to get you the eyeballs necessary to help you resolve your issue.
Welcome to the forum. I don't think you'll get a lot of info from us on this thread because this thread is specifically talking about excessive carbon buildup on direct injected gasoline cars. I believe your cgi is a diesel, and thus most of us don't have any experience working with that. Hopefully someone else can chime in here. Personally, I'd start another thread instead of posting in this one if in fact your car is a diesel to get you the eyeballs necessary to help you resolve your issue.
MBWorld Fanatic!
Joined: Jun 2011
Posts: 2,400
Likes: 259
From: Canada
A car
Junior Member
Joined: Jan 2018
Posts: 28
Likes: 5
From: South Florida
Mercedes Benz C250 Sedan 2012
Hello guys, I previously posted a new thread regarding a check engine light that seems to occur occasionally. I have a C250 with the 1.8 4 cylinder turbo (M271 EVO) car does have a lot of miles.
However, I don't know how to diagnose if it is suffering from carbon build up. After I park the vehicle I do smell a weird mixture of oil/gas and the exhaust pipe sometimes smokes a bit longer.... Most of the time the car is fine. I at first attributed to the cold New England weather but it persisted throughout warmer days.
However, I don't know how to diagnose if it is suffering from carbon build up. After I park the vehicle I do smell a weird mixture of oil/gas and the exhaust pipe sometimes smokes a bit longer.... Most of the time the car is fine. I at first attributed to the cold New England weather but it persisted throughout warmer days.
Member
Joined: Jun 2017
Posts: 84
Likes: 8
2013 benz c250
Question.... I've been watching vids and researching online line for the past 3 months now about Oil Catch cans... From what I can see, they do work. However, from what I am reading on this forum about people's opinions that they do not work... The thought crosses my mind on whether or not those who bought a OCC, could have just bought the wrong kind or too cheap of an OCC? There are many types on the market and from what I've seen many would not work properly IF they don't have that filter, mesh or divider inside of the can. So I'm wondering if those who had problems with their OCC, if they may have just needed to get a better quality OCC?
I ask this question because from my research, I've found that, YES, there are inherently known issues with OCC's that don't have the right separator or filtration systems inside of them (meaning oil and water going past the can and into the intake manifold) all because the OCC's they had were nothing but an open empty can. OR because some people had let the can fill up to the point where the contents leaked out into the intake system.
Just a thought
Senior Member
Joined: Aug 2019
Posts: 285
Likes: 77
2019 GLC300, 2017 E300
Question.... I've been watching vids and researching online line for the past 3 months now about Oil Catch cans... From what I can see, they do work. However, from what I am reading on this forum about people's opinions that they do not work... The thought crosses my mind on whether or not those who bought a OCC, could have just bought the wrong kind or too cheap of an OCC? There are many types on the market and from what I've seen many would not work properly IF they don't have that filter, mesh or divider inside of the can. So I'm wondering if those who had problems with their OCC, if they may have just needed to get a better quality OCC?
I ask this question because from my research, I've found that, YES, there are inherently known issues with OCC's that don't have the right separator or filtration systems inside of them (meaning oil and water going past the can and into the intake manifold) all because the OCC's they had were nothing but an open empty can. OR because some people had let the can fill up to the point where the contents leaked out into the intake system.
Just a thought
I ask this question because from my research, I've found that, YES, there are inherently known issues with OCC's that don't have the right separator or filtration systems inside of them (meaning oil and water going past the can and into the intake manifold) all because the OCC's they had were nothing but an open empty can. OR because some people had let the can fill up to the point where the contents leaked out into the intake system.
Just a thought
I have a daily driver Hyundai Accent 1.6 GDI. @ 7.5k miles I installed a Jegs Air/Oil separator. At 11k, I did a valve cleaning with the CDC GDI IVD cleaner. Tons of white smoke. Repeated at 22k and similar results, less smoke. Repeated at 33k, very little to no smoke. I'm at 65k and about to repeat.. but that little air/oil separator collects ~1 tbsp. every ~600 miles. Running Amsoil OE synthetic and top tier fuel. I haven't scoped the intake tract, but the car runs like a top. I've heard of others having issues, so I wanted to be proactive.
Searching for a catch can kit for the GLC, although the stock oil separator system seems pretty decent. It recirculates the oil back to the engine though vs. draining.. planning on more frequent intervals for oil changes (she currently has 3.5k miles on it) to prevent issues in the future.
