C-Class 1999 W202 Misfire Problem
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C-Class 1999 W202 Misfire Problem
Hi all,
This is my first post so please excuse me if I sound like a noob.
Car Info
Model:C-Class C180
Year: 1999
Type: W202
Engine: M111.921
I purchased a C180 earlier this year. It's been running really well for months however it's recently developed a bit of an issue. Over the last couple months, if I try to drive on a cold engine, the car just jerks as if it's got no power whatsoever. It won't accelerate at all, almost as if it's not being given any fuel. The only way to drive it is to accelerate from 900rpm - 1500rpm and then change to the next gear and so on, until you reach road speed. The issue begins to resolve itself as the engine warms up. However, if I start the car and allow it to warm up to 90degrees before driving it, it performs pretty much fine.
Also, regardless of the above, another issue began occurring at the same time. When driving on Motorways, the car randomly loses power at around 70-80mph. It's only a very short loss of power and it can be regained in a couple of seconds by releasing the accelerator and then pressing down on it again slowly and gently.
In general, the car itself feels quite under-powered. I understand it's a heavy car but I have a strong suspicion that it's not giving me all the power it has under the bonnet.
I didn't really attend to the issue initially because I knew the car was due for service shortly. Anyway, I had my Dad take the car for it's service and MOT last week at a family friend's garage. It passed the MOT without issue. It was serviced also and was it was plugged into the Mercedes Star Diagnostics system. The mechanic explained to my Dad that a couple of cylinders were misfiring. He attended to it and said "It's fine now". I suspect he changed the plugs. Being a family friend, I was charged very little for all the work and as a result I can't really complain. Also the garage is pretty far away and going back there comes at a high cost for me.
My Mum's brother is a very experienced mechanic also, and we met over the weekend. He explained to me that I should just change the plug leads as the car sounds like it's misfiring and the leads sound like the culprits. When I inspected the engine, I couldn't identify any traditional plug-leads. So I called my uncle back and explained what I could see. He then advised me to purchase 1x Ignition Coil Pack and replace one of the existing ones. If I noticed a difference, I should consider my problem solved. If not, he said I should put the original coil pack back, and replace the next one instead and so on until I identify the faulty pack/s.
He said, they're really easy to swap. So, I tried to identify the packs. I couldn't work out where they are and how to access them. I'm not a dufus and have previously serviced my older cars with ease. However this is my first Mercedes and I'm out of practice. I've attached pictures of my engine and would appreciate any advice, direction & guidance any of you can offer me.
Many thanks & kind regards,
Mr Beats
This is my first post so please excuse me if I sound like a noob.
Car Info
Model:C-Class C180
Year: 1999
Type: W202
Engine: M111.921
I purchased a C180 earlier this year. It's been running really well for months however it's recently developed a bit of an issue. Over the last couple months, if I try to drive on a cold engine, the car just jerks as if it's got no power whatsoever. It won't accelerate at all, almost as if it's not being given any fuel. The only way to drive it is to accelerate from 900rpm - 1500rpm and then change to the next gear and so on, until you reach road speed. The issue begins to resolve itself as the engine warms up. However, if I start the car and allow it to warm up to 90degrees before driving it, it performs pretty much fine.
Also, regardless of the above, another issue began occurring at the same time. When driving on Motorways, the car randomly loses power at around 70-80mph. It's only a very short loss of power and it can be regained in a couple of seconds by releasing the accelerator and then pressing down on it again slowly and gently.
In general, the car itself feels quite under-powered. I understand it's a heavy car but I have a strong suspicion that it's not giving me all the power it has under the bonnet.
I didn't really attend to the issue initially because I knew the car was due for service shortly. Anyway, I had my Dad take the car for it's service and MOT last week at a family friend's garage. It passed the MOT without issue. It was serviced also and was it was plugged into the Mercedes Star Diagnostics system. The mechanic explained to my Dad that a couple of cylinders were misfiring. He attended to it and said "It's fine now". I suspect he changed the plugs. Being a family friend, I was charged very little for all the work and as a result I can't really complain. Also the garage is pretty far away and going back there comes at a high cost for me.
My Mum's brother is a very experienced mechanic also, and we met over the weekend. He explained to me that I should just change the plug leads as the car sounds like it's misfiring and the leads sound like the culprits. When I inspected the engine, I couldn't identify any traditional plug-leads. So I called my uncle back and explained what I could see. He then advised me to purchase 1x Ignition Coil Pack and replace one of the existing ones. If I noticed a difference, I should consider my problem solved. If not, he said I should put the original coil pack back, and replace the next one instead and so on until I identify the faulty pack/s.
He said, they're really easy to swap. So, I tried to identify the packs. I couldn't work out where they are and how to access them. I'm not a dufus and have previously serviced my older cars with ease. However this is my first Mercedes and I'm out of practice. I've attached pictures of my engine and would appreciate any advice, direction & guidance any of you can offer me.
Many thanks & kind regards,
Mr Beats
Last edited by MercedesBeats; Nov 29, 2011 at 05:56 AM. Reason: Missed something
Junior Member
Joined: Dec 2011
Posts: 6
I beleive coils are under the cover as I have shown in your original image attached. You will have to remove Air Pipe above this cover before you can open the cover where all spark plugs and coils are located.
Did you get any error code ?.
Also, did you check your AIR Mass Flow ?. I have similar issue with MAF and changing Original Bosch Part, resolved this issue. I have MB 1999 C230 and i have heard this is very common issue in all C Series cars. Check if MAF got any Oil in there. You may clean your MAF with MAF Cleaner and may run car good for couple of days but you will have to change MAF eventually if it is MAF issue. If you see oil in MAF, I would recommend you to change your PCV Valve(under the car) and Oil Seperator as well.
Did you get any error code ?.
Also, did you check your AIR Mass Flow ?. I have similar issue with MAF and changing Original Bosch Part, resolved this issue. I have MB 1999 C230 and i have heard this is very common issue in all C Series cars. Check if MAF got any Oil in there. You may clean your MAF with MAF Cleaner and may run car good for couple of days but you will have to change MAF eventually if it is MAF issue. If you see oil in MAF, I would recommend you to change your PCV Valve(under the car) and Oil Seperator as well.
Last edited by lordofthering; Dec 3, 2011 at 10:01 PM.
Junior Member
Joined: Dec 2011
Posts: 5
echoing what lordofthering said - I too have a 99 C230k and went through the same issue. oil separator & related hoses, plus air flap actuator (on the air box), dropped the intercooler & flushed w/ carb cleaner, then cleaned the MAF (MAF cleaner only). Then, yes, new coils & plugs. Sounds like a lot, but well worth the effort.
The worst part of the job was the intercooler... and still it was mostly compliant.
hope this helps,
Ed
The worst part of the job was the intercooler... and still it was mostly compliant.
hope this helps,
Ed
Last edited by Ed_in_Va; Dec 28, 2011 at 09:56 AM. Reason: typo
Member
Joined: May 2008
Posts: 50
From: Norway, China!
Somthing to do with warm\cold sensors? Check the wiring from the intake filter?
I had my top off on this car, because it went too hot in the summer. (this was a 1994 that rounded 200.000km/120.000miles?). After that great job, I could not hear any "tickling different", - it ran perfect!
BUT, beware of the the individually coils. It could be something easy like that!
Have somebody to diagnose the car, it may tell something whats wrong!
I had my top off on this car, because it went too hot in the summer. (this was a 1994 that rounded 200.000km/120.000miles?). After that great job, I could not hear any "tickling different", - it ran perfect!
BUT, beware of the the individually coils. It could be something easy like that!
Have somebody to diagnose the car, it may tell something whats wrong!
Last edited by Arildo; Jan 6, 2012 at 09:12 PM.
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