Possible problem with my 271 engine?
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Joined: Oct 2004
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From: Las Vegas, Nevada
2013 C350 Coupe, 2005 C230K Kleemann Sedan, 2013 GLK350 4matic
Possible problem with my 271 engine?
I have been chasing a P0420 code for about a year and a half now, so I decided to spend an afternoon to clean the MAF and change the plugs.
The MAF was actually very clean, however, the connecting tube (the one with the pain in the butt clamps) was oily on the outside and had some oil residue on the inside of the rubber acordian tube by he firewall.
So, I next changed out my spark plugs at 58000 miles with the stock Bosch replacements. The front two plugs had signs of oil on the coil tubes and the top part of the plugs, so I may have a leaking gasket somewhere. The front two plugs have evidence of oil in the cylinder as well.
The rear two plugs were dry with just black with the centers of the plugs were tan in color. The coil tubes for the back two plugs were dry.
Would this possibly cause the P0420 code that I have been getting? I will probably have to change the valve cover gasket to see if that caused the leak. Would a valve cover gasket leak get oil into the cylinder? The engine sounds and runs fine and does not use any oil between oil changes.
The MAF was actually very clean, however, the connecting tube (the one with the pain in the butt clamps) was oily on the outside and had some oil residue on the inside of the rubber acordian tube by he firewall.
So, I next changed out my spark plugs at 58000 miles with the stock Bosch replacements. The front two plugs had signs of oil on the coil tubes and the top part of the plugs, so I may have a leaking gasket somewhere. The front two plugs have evidence of oil in the cylinder as well.
The rear two plugs were dry with just black with the centers of the plugs were tan in color. The coil tubes for the back two plugs were dry.
Would this possibly cause the P0420 code that I have been getting? I will probably have to change the valve cover gasket to see if that caused the leak. Would a valve cover gasket leak get oil into the cylinder? The engine sounds and runs fine and does not use any oil between oil changes.
Last edited by capt_paul; Apr 9, 2009 at 11:03 PM.
Thread Starter
MBWorld Fanatic!
Joined: Oct 2004
Posts: 1,305
Likes: 37
From: Las Vegas, Nevada
2013 C350 Coupe, 2005 C230K Kleemann Sedan, 2013 GLK350 4matic
I am almost tempted to replace the Kleemann cat with some other aftermarket one, or welding on the stock cat from the original exhaust manifold.
Kleemann headquarters tells me that the P0420 code issue is the only one they have heard of globally, even though I have heard the same issues with several other members of this forum.
I also may go back to a stock setup since the car will not pass emissions test with a set CEL code.
Kleemann headquarters tells me that the P0420 code issue is the only one they have heard of globally, even though I have heard the same issues with several other members of this forum.
I also may go back to a stock setup since the car will not pass emissions test with a set CEL code.
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Joined: Dec 2005
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From: SoCal. Desert
'16 E350, gone: '03 c230k
Have you replaced the "$12 hose" yet? You also might look for a vacuum leak (cracked hose) somewhere else. Sometimes on boosted cars the small cracks/leaks only manifest themselves under pressure until they get worse. Black plugs on a boosted car sometimes indicate vacuum leaks. The computer is trying to add more fuel (i.e. will burn rich) because it thinks all the air is going into the cylinder when in actuality some is being lost thru the leak. This is opposite from a normally aspirated car, where under vacuum the leak is sucking in more air than the computer thinks hence a lean condition.
This is just a thought, in hopes the problem is something simple and not serious....
This is just a thought, in hopes the problem is something simple and not serious....
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
