500 7G less power, petrol smell, rough idling
Thread Starter
Newbie
Joined: Jan 2017
Posts: 3
Likes: 0
CLK 500
500 7G less power, petrol smell, rough idling
Hello guys,
I am having a problem with my CLK 500. Some time ago it started rough idling, it has less power (about 4s more 100-200km/h) and it smells like hell behind my car when i floor it. Mechanic said that there is no fault code in SD, but he recommends to change ignition coils and spark plugs. So did I. Nothing has changed. I went to the other mechanic. After scanning my car with SD he said that MAF shows 1.05V which is too high, so I need a new one. So I bought it and nothing has changed. Ignition system is OK (thats what they say), compression is ok. Is it possible that one of the ignition wires is faulty, but SD doesnt see it? Sonda lambda maybe? Catalyst? Do you have any ideas? I really dont want to change all parts in my car. I really love CLK.
Regards
I am having a problem with my CLK 500. Some time ago it started rough idling, it has less power (about 4s more 100-200km/h) and it smells like hell behind my car when i floor it. Mechanic said that there is no fault code in SD, but he recommends to change ignition coils and spark plugs. So did I. Nothing has changed. I went to the other mechanic. After scanning my car with SD he said that MAF shows 1.05V which is too high, so I need a new one. So I bought it and nothing has changed. Ignition system is OK (thats what they say), compression is ok. Is it possible that one of the ignition wires is faulty, but SD doesnt see it? Sonda lambda maybe? Catalyst? Do you have any ideas? I really dont want to change all parts in my car. I really love CLK.
Regards
MBWorld Fanatic!
Joined: Jun 2008
Posts: 1,227
Likes: 61
From: Atlanta Metro
2008 clk550 - Navigator - Frontier
What kind of smell are you getting when you floor it? Does it smell like gasoline or does it smell like sulfur? If it smells like gas, it may be a faulty plug or ignition coil. But you should get a code if this is the case. If it smells like sulfur it may be your catalytic converter/s. And if the cat converter core has broken loose, whole or part, it can block the exhaust flow and result in poor acceleration/pickup.
Look into your tailpipe with a flashlight to see if there are pieces of cat core lodged near the exit. Since the core is likely ceramic and not metallic, you may not see anything. You can also rev it a few times while parked and see if there is any metallic or ceramic residue/particles on the ground just aft of tailpipe opening. You might also hear a rattle in the exhaust pipe if the cat core has broken.
The 550 uses perforated straight through pipe after the cats through the resonator and muffler, so small loose pieces will would find their way to the exhaust exit. I do not know if the 500 muffler is chambered. If so, broken pieces of cat core may become lodged in the chambers.
Look into your tailpipe with a flashlight to see if there are pieces of cat core lodged near the exit. Since the core is likely ceramic and not metallic, you may not see anything. You can also rev it a few times while parked and see if there is any metallic or ceramic residue/particles on the ground just aft of tailpipe opening. You might also hear a rattle in the exhaust pipe if the cat core has broken.
The 550 uses perforated straight through pipe after the cats through the resonator and muffler, so small loose pieces will would find their way to the exhaust exit. I do not know if the 500 muffler is chambered. If so, broken pieces of cat core may become lodged in the chambers.
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
