Mercedes-Benz Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
58 Posts
Discussion Starter #1
My check engine light in on non-stop. My mechanic told me my exaust valves or pipes are clogged with Carbon. My mechanic said this doesnt's effect the performance in any way whatsoever. Is this true ?

He said the owner before me probably used it as a cruising car around town---and never took it on long road trip at high speeds. He recommended taking it out and going to Vegas--and drive like 90-100 mph--this might just clean out all the carbon.

He said it happens on S classes, and Porsches. Even low mileage cars can get carbon clogging.

He said to fix it--he would have to tak the engine apart and clean it out---around $ 3,500 - $ 5,000. Is this accurate ?

Is it imperative that I clean it out ?

Pretty much he said I can ignore it, and just drive it. But I will not pass my smog test in 2 years. But actually, a smog shop sold me the car, so hopefully they will still pass me.

Anyone had this problem on their W 140 ? ("Carbon Clogging") ????
 

·
Registered
SEC 600 V12 2dr COUPE (RHD) One of the chosen few.
Joined
·
2,233 Posts
You will get that problem if its job was to cruise in traffic .. However.. there is this sticky thing in the middle..by the side of the seat.... instead of D try it through the gears ...first is astronomic.. Be carefull It will go like a rocket..you can safely rev it past 5000.

BUT First do an oil and air filter change then the plugs.. A injector -engine cleanser first tankfull .. followed a tankful later by a cat cleanser .. then a trip to the indy garage.. to have the ECU adaptive reset..then see how things feel... It is true that a lot of these engines never see above 2-3K but you have the stick...give it some heavy right foot.. but please be carefull.. a sraight road.. with little traffic.. and no enforcement people..and NO SCREAMING.. you will disurb the sleeping...Ah.. and a picture of your grin.. when you get back home..
 

·
Registered
Joined
·
185 Posts
Most Hi-Performance engines are prone to carbon build up.
An Easy remedy is some chemicals and a good highway drive.
Also look at least to drive the car on the highway for at least 1 or 2 times a week for at least 15-20 minutes and don't be afraid to open the throttle up wide open.
Anoather thing you might want to try is Sea Foam...
works really good but the only downfall is that after the treatment you will end up with the batmobile smoke screen !!
Works wonders though.
Sea Foam
 

·
Registered
Joined
·
58 Posts
Discussion Starter #4
Most Hi-Performance engines are prone to carbon build up.
An Easy remedy is some chemicals and a good highway drive.
Also look at least to drive the car on the highway for at least 1 or 2 times a week for at least 15-20 minutes and don't be afraid to open the throttle up wide open.
Anoather thing you might want to try is Sea Foam...
works really good but the only downfall is that after the treatment you will end up with the batmobile smoke screen !!
Works wonders though.
Sea Foam
----------------
When you say take it out, how fast do I need to go ?
And the Seam Foam & The smoke, is that just temporary ? What do you mean exactly ?
 

·
Registered
Joined
·
58 Posts
Discussion Starter #5
I have done the filter and other changes you mention.

How fast do I need to floor it to de-clog it ?

If I continue to drive the car with clogged filters, is it like a guy with high cholesterol---will he have a heart attack one day ?

If I keep driving it clogged--will it destroy the engine ?

My mechanic said it was no big deal.
 

·
Registered
Joined
·
185 Posts
its just like working out.
you don't want to ever do it the first time, take it easy and ease in and progressively push her a lil more.
my advice is to warm her up to operating temperatures before you start belting her, get on the high way and shift down and keep the rpms at about 3000-3500 for about 2 minutes and then shift back up into D and then cruise again.
repeat that a couple of times slowly increasing the duration and it should clear everything out like that in about a couple of hours.
do it slowly ..
you dont want to go nuts all at once since you can clog the catalitic converters.

your mechanic is sorta right, since if left alone will cause drivability issues and seen even worse where the build up was so extreme when it chipped it got stuck in between the valve and the valve seat :eek:
im not sure, but i bet the M120 and M119 are interference type engines :crybaby2:
 

·
Registered
Joined
·
58 Posts
Discussion Starter #7
its just like working out.
you don't want to ever do it the first time, take it easy and ease in and progressively push her a lil more.
my advice is to warm her up to operating temperatures before you start belting her, get on the high way and shift down and keep the rpms at about 3000-3500 for about 2 minutes and then shift back up into D and then cruise again.
repeat that a couple of times slowly increasing the duration and it should clear everything out like that in about a couple of hours.
do it slowly ..
you dont want to go nuts all at once since you can clog the catalitic converters.

your mechanic is sorta right, since if left alone will cause drivability issues and seen even worse where the build up was so extreme when it chipped it got stuck in between the valve and the valve seat :eek:
im not sure, but i bet the M120 and M119 are interference type engines :crybaby2:
--------------
A couple of questions:

1) If I continue driving the car, 'crusing' around town--which is what I basically do with the car, and the carbon stays clogged, will it cause any other damage to the car ?

2) Does the carbon clogging affect gas mileage ?? (I would think it would)

3) Can the car last a long time with the carbon clogging ?
(My mechanic says that his Porsche 911 has the same problem, and it only has 30K miles on it....)
 

·
Registered
Joined
·
185 Posts
--------------
A couple of questions:

1) If I continue driving the car, 'crusing' around town--which is what I basically do with the car, and the carbon stays clogged, will it cause any other damage to the car ?
It all depends...
I seen a lot of things as a tech and theres still lots that i haven't but i heard a lot of horror stories, but those always tend to be blown out of proportion as usual. My main concern will be the clearing process. it has to go somewhere an the exhaust component downstream is the catalytic converter, and if you rush it you can clog them.

2) Does the carbon clogging affect gas mileage ?? (I would think it would)
Is sure does, since it restricts exhaust flow and the engine has to work harder to make the same power.

3) Can the car last a long time with the carbon clogging ?
(My mechanic says that his Porsche 911 has the same problem, and it only has 30K miles on it....)
Its normal for these high performance engine to have these issues, thats why premium fuel is recomended and try to trow in a fuel system treatment every 3rd tank or so, but also the key is to keep her clean is to take her out of the city and hit the highway for a good half an hour to an hour every weekend.
 

·
Premium Member
1997 S600 (sold)
Joined
·
4,660 Posts
My check engine light in on non-stop. My mechanic told me my exaust valves or pipes are clogged with Carbon. My mechanic said this doesnt's effect the performance in any way whatsoever. Is this true ?

He said the owner before me probably used it as a cruising car around town---and never took it on long road trip at high speeds. He recommended taking it out and going to Vegas--and drive like 90-100 mph--this might just clean out all the carbon.

He said it happens on S classes, and Porsches. Even low mileage cars can get carbon clogging.

He said to fix it--he would have to tak the engine apart and clean it out---around $ 3,500 - $ 5,000. Is this accurate ?

Is it imperative that I clean it out ?

Pretty much he said I can ignore it, and just drive it. But I will not pass my smog test in 2 years. But actually, a smog shop sold me the car, so hopefully they will still pass me.

Anyone had this problem on their W 140 ? ("Carbon Clogging") ????
Need more information. What year car? I'm going to go out on a limb and say that your car is 1996 or later and that your fault code is P0410. If so, then here is a recent thread for you. You should read the entire thread word for word.

http://www.benzworld.org/forums/w140-s-class/1368297-frustrated-secondary-air-injection.html

I'm guessing that your mechanic owns a 1995 to 1998 Porsche 911. The 3.6 L engines in these cars were notorious for the secondary air injection ports getting clogged with carbon causing check engine lights. For many years the only remedy used by mechanics was to remove the cylinder heads from the engine and clean the ports out off the engine. Big bucks. More recently, good independent mechanics have found that they can successfully clean the ports in these 911 engines with the engine still in the car using solvent sprays (e.g. carb cleaner). This a much cheaper solution, obviously.

It appears that your mechanic is quoting for cylinder head removal to clear the air injection ports, which means the quote is reasonable. Lots of labor involved. The issue is specifically carbon build up in the air injection ports, not general carbon build up in the cylinders, on valves, on spark plugs, or in the exhaust pipes. I doubt that the "Italian tune ups" mentioned by others will be helpful (IF this is the problem), but it certainly can't hurt to try. It's free afterall.

But, if your fault code is not P0410, then what I've said likely doesn't apply to you. We need those codes or we're no real help.

You can also search P0410 over this entire site to find what others have done with this code. It is not something specific to the W140.

If the problem is in fact clogged air injection ports, it is not imperative that you clean them out with regard to engine health. The air injection system is only an emissions reduction measure. It is not required to be functioning for the health of the engine (only for the health of the environment). As mentioned, you will not pass a smog check with an active check engine light.

Brett
 

·
Registered
Joined
·
58 Posts
Discussion Starter #10
Mechanic Said it's an emissions issue

Need more information. What year car? I'm going to go out on a limb and say that your car is 1996 or later and that your fault code is P0410. If so, then here is a recent thread for you. You should read the entire thread word for word.

http://www.benzworld.org/forums/w140-s-class/1368297-frustrated-secondary-air-injection.html

I'm guessing that your mechanic owns a 1995 to 1998 Porsche 911. The 3.6 L engines in these cars were notorious for the secondary air injection ports getting clogged with carbon causing check engine lights. For many years the only remedy used by mechanics was to remove the cylinder heads from the engine and clean the ports out off the engine. Big bucks. More recently, good independent mechanics have found that they can successfully clean the ports in these 911 engines with the engine still in the car using solvent sprays (e.g. carb cleaner). This a much cheaper solution, obviously.

It appears that your mechanic is quoting for cylinder head removal to clear the air injection ports, which means the quote is reasonable. Lots of labor involved. The issue is specifically carbon build up in the air injection ports, not general carbon build up in the cylinders, on valves, on spark plugs, or in the exhaust pipes. I doubt that the "Italian tune ups" mentioned by others will be helpful (IF this is the problem), but it certainly can't hurt to try. It's free afterall.

But, if your fault code is not P0410, then what I've said likely doesn't apply to you. We need those codes or we're no real help.

You can also search P0410 over this entire site to find what others have done with this code. It is not something specific to the W140.

If the problem is in fact clogged air injection ports, it is not imperative that you clean them out with regard to engine health. The air injection system is only an emissions reduction measure. It is not required to be functioning for the health of the engine (only for the health of the environment). As mentioned, you will not pass a smog check with an active check engine light.

Brett
BRETT-

You are so on the money. I am 99% sure the fault code is P0410. My mechanic said it's related to emissions reduction. He advised me to leave it alone or drive to Vegas and back a couple of times. (from California).

The Sea Foam that has been mentioned--is that a viable measure---or is that for something else.

Anway, if my code is P0410--my car won't die ? It can live a long and rich life ? That's my main concern.

And oddly enough, I bought the car from a Smog Station Shop 3 months ago. They said that one way or another, in 2 yes, when it's time to get smogged, I will pass.

So, if I can pass my smog test, but the check engine light remains on due to that code, is it something that I can live with, assuming I dont drive to Vegas ?
 

·
Premium Member
1997 S600 (sold)
Joined
·
4,660 Posts
BRETT-

You are so on the money. I am 99% sure the fault code is P0410. My mechanic said it's related to emissions reduction. He advised me to leave it alone or drive to Vegas and back a couple of times. (from California).

The Sea Foam that has been mentioned--is that a viable measure---or is that for something else.

Anway, if my code is P0410--my car won't die ? It can live a long and rich life ? That's my main concern.

And oddly enough, I bought the car from a Smog Station Shop 3 months ago. They said that one way or another, in 2 yes, when it's time to get smogged, I will pass.

So, if I can pass my smog test, but the check engine light remains on due to that code, is it something that I can live with, assuming I dont drive to Vegas ?
My next question is, "What kind of diagnostics did the mechanic do to prove that the problem was plugged air injection ports?" There are several possible failures that can cause the car to fail the ECU's air injection self-diagnostic test resulting in the check engine light and the P0410 code. Read the thread I posted to see some discussion of them.

There are no downsides to not fixing the air injection system besides not being able to pass smog tests in areas that require them.

When added to the gas, Sea Foam is for cleaning the injectors, intake, cylinders, pistons and rings, and valves of deposits. I don't see how it would have any solvating power in the exhaust once it has been through combustion in the cylinders.

Brett
 

·
Registered
Joined
·
58 Posts
Discussion Starter #12
My next question is, "What kind of diagnostics did the mechanic do to prove that the problem was plugged air injection ports?" There are several possible failures that can cause the car to fail the ECU's air injection self-diagnostic test resulting in the check engine light and the P0410 code. Read the thread I posted to see some discussion of them.

There are no downsides to not fixing the air injection system besides not being able to pass smog tests in areas that require them.

When added to the gas, Sea Foam is for cleaning the injectors, intake, cylinders, pistons and rings, and valves of deposits. I don't see how it would have any solvating power in the exhaust once it has been through combustion in the cylinders.

Brett
Brett-

Once again, you are spot on. After speaking with over half a dozen MBZ mechanics--the concensus is clear---dont do anything.

$ 3500 to clean the Cylinder heads and ports. But a risk later on a an oil valve leakage. The put the cylinders in a hot tank and boil it. IN doing this I guess the valves can deteriorate. So there is a risk.

Fuel additive will do nothing, since the problem is in the Cylinder heads.

However, about 10% of the time, if you remove the EGR, and look and the manifold intake, there could be some cloggage there-and presto, your problem is solved, with no need to spend beaucoup bucks.

90% of the time, it's the cylinder heads. This is something you have to live with. Over years and years of usage and driving, if some cylinders are richer than others, that imbalance of the distribution of flow could have it's impact.

In conclusion, after all the research, do nothing. Live with the check engine light. Maybe go out to the desert and drive the car, and get those RPM's high, but most likely, the only true fix is the cleaning of the cylinder heads---which is costly.

I have decided I will ask my mechanic if he will remove the EGR and check the manifold intake--if that's ok, then I know what to do. Nothing.

Enjoy the car with the check engine light. And take my car to the smog station that sold me the car every 2 years and pass my smog test.

Fuel additives will not solve this problem since it's the cylinder heads.
 

·
Premium Member
1997 S600 (sold)
Joined
·
4,660 Posts
Which W140 do you have, and what model year? Are you sure your car has an EGR valve? My 1997 S600 doesn't. Secondary air injection and exhaust gas recirculation (EGR) are different things.

Brett
 

·
Registered
Joined
·
58 Posts
Discussion Starter #14
EGR - MANIFOLD INTAKE

Which W140 do you have, and what model year? Are you sure your car has an EGR valve? My 1997 S600 doesn't. Secondary air injection and exhaust gas recirculation (EGR) are different things.

Brett
I have a 1997 S500.

I believe there is an EGR on mine....the mechanic said you remove the EGR, and look at the manifold intake--a lot of the time the carbon gets stuck there, and you can access it and clean it. A lot easier than removing cylinder heads.
 

·
Moderator
93 SL500, 95 SL320, 96 S320, 98 S500, 2002 E320 4Matic Wagon & A little 91 5.0 FORD Mustang
Joined
·
8,064 Posts
First, I would pull the OBDII codes-you may have P0410 and P0300(EGR-I think). It may be a simple fix or "multi" dollar fix (not sure if you are in the USA). I just fixed my P0410 and P0300 although my fix was a easy fix. I did air passages test for the EGR and the air injection, and passages were clear. I did spend seven hours checking things out, but all worth the education to solve the problem. My problem was a simple Y-vacuum fitting that feeds both the EGR and Airpump solenoid. I was planning to do a DIY write-up with lot of pictures later. The Y-vacuum fitting is a seven-dollar part.

Martin
 

·
Registered
1986 560SEL, 1986 560SEL, 1992 500SEL, 1999 S500
Joined
·
473 Posts
According to my old 126 manuals (560SEL) Mercedes dealerships had a procedure for de-carbonizing the backsides of the intake and exhaust valves with the heads left on the engine. I believe they removed the exhaust manifolds and the air cleaner. They used a media blasting setup to blast ground walnut shells into the runners and an industrial grade vacuum to remove the debris. This was done with both valves in the closed position so nothing got in the combustion chamber. The walnut is hard enough to break up the deposites but won't harm the valves or the alloy intake and heads.
 

·
Registered
Joined
·
18 Posts
air injection ports clogged

I have seen every remedy and possible "try this" seafoam blaaaaaa. IT DOES NOT WORK. The air injection ports that travel throughout the cylinder head and exit behind the exhaust valves cannot be simple cleaned. The cylinder heads need to be removed. The exhaust valves removed and a serious break apart cleaning is the only way to eliminate the baked in carbon. I've done it plenty of times.
 
1 - 17 of 17 Posts
Top