Limp Mode after Spark Plug Change
Thread Starter
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Joined: Aug 2004
Posts: 791
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From: Detroit Area
W203 C230, W210 E350, W166 ML63
Limp Mode after Spark Plug Change
I just changed out my spark plugs at 85K for the first time. I have a 2004 C230 Sedan. After I changed them out I was not sure whether or not I needed to unplug the battery to reset the ECU so I did not but I did do the pedal ECU reset. Car ran smooth when I turned it on and drove to the store however when driving back home and merging onto an expressway I felt a total power loss. It felt as if the car was in limp mode and maybe the supercharger was not working. Any ideas on what is going on? No CEL or any other kinds of errors.
Thread Starter
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Joined: Aug 2004
Posts: 791
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From: Detroit Area
W203 C230, W210 E350, W166 ML63
So I decided to unplug my battery and see what happens. I turned my car on, sounds fine, drove it up to 60 mph and is changing gears great working the same as it always has. Took it on an on ramp onto the expressway got it up to 70 and it stutters and goes into limp mode with the CEL going on. Now its limp all the way through and not just at higher speeds. 1st gear, 2nd gear, 3rd gear all have terrible accelerations. I plugged in my scanner and it gave me 2 codes.. p0237 and p0237 p. I looked them up and they are supercharge bypass.... why would this be happening after an install of new spark plugs? I should add that my car has ran really rich for the last 7 years. Morning start ups always included a cloud of white smoke from the exhaust with a bad smell. Is it possible my car is running more lean now with the better spark plugs and is causing the ECU to put my car into limp mode?
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Joined: May 2009
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From: Toronto, Ontario, Canada, eh!
2003 C230 Sports Coupe, Paprika Metallic Red, Auto, Pano, Leather
If you put your old plugs back in and all your problems go away,... then you'll know the problem is with your new plugs.
Did you get the right plugs? Set proper gap? Didn't mess up the order of the spark plug wire.
In Detroit area, All European Auto Supply at 308 East Parent Avenue in Royal Oak, Michigan is a great source for parts and advice,.... for me, it's worth the 4 hour drive from Toronto. http://www.alleuro.com/
BTW, limp mode is a transmission issue,.... that won't allow you to go into higher gear and limit your speed,.... it sounds more like you have an acceleration issue. Try transmission adaptive (ECU) reset.
Did you get the right plugs? Set proper gap? Didn't mess up the order of the spark plug wire.
In Detroit area, All European Auto Supply at 308 East Parent Avenue in Royal Oak, Michigan is a great source for parts and advice,.... for me, it's worth the 4 hour drive from Toronto. http://www.alleuro.com/
BTW, limp mode is a transmission issue,.... that won't allow you to go into higher gear and limit your speed,.... it sounds more like you have an acceleration issue. Try transmission adaptive (ECU) reset.
Last edited by SunnyRayToronto; Apr 6, 2015 at 01:24 AM.
Thread Starter
Super Member
Joined: Aug 2004
Posts: 791
Likes: 37
From: Detroit Area
W203 C230, W210 E350, W166 ML63
If you put your old plugs back in and all your problems go away,... then you'll know the problem is with your new plugs.
Did you get the right plugs? Set proper gap? Didn't mess up the order of the spark plug wire.
In Detroit area, All European Auto Supply at 308 East Parent Avenue in Royal Oak, Michigan is a great source for parts and advice,.... for me, it's worth the 4 hour drive from Toronto. http://www.alleuro.com/
BTW, limp mode is a transmission issue,.... that won't allow you to go into higher gear and limit your speed,.... it sounds more like you have an acceleration issue. Try transmission adaptive (ECU) reset.
Did you get the right plugs? Set proper gap? Didn't mess up the order of the spark plug wire.
In Detroit area, All European Auto Supply at 308 East Parent Avenue in Royal Oak, Michigan is a great source for parts and advice,.... for me, it's worth the 4 hour drive from Toronto. http://www.alleuro.com/
BTW, limp mode is a transmission issue,.... that won't allow you to go into higher gear and limit your speed,.... it sounds more like you have an acceleration issue. Try transmission adaptive (ECU) reset.
I did get a Check Engine Light last night after this post and it read as code p0237 which is a supercharged bypass issue. Upon further inspection I noticed that there was a huge clamp at the bottom of my engine bay. I looked at the supercharger and noticed that the large hose seems to be somewhat pushed off the supercharge exposing another red entrance hose. I am thinking that this clamp may have fell off after boosting or was not put on properly when I had my belts changed at the dealership 3 months ago. Does that sound somewhat possible?
Thread Starter
Super Member
Joined: Aug 2004
Posts: 791
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From: Detroit Area
W203 C230, W210 E350, W166 ML63
Bosch Double Platinum. I don't think its the spark plugs because I am actually getting better mpg than I was before I had my spark plugs changed. I just lose boost after I pass 65mph and it goes into limp mode. If I stay under 65 the car is running fine.
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Joined: Aug 2004
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From: Detroit Area
W203 C230, W210 E350, W166 ML63
This is a photo of the 2nd spark plug after I removed the coil pack. It did have some oil present but I used a vacuum to clean it up along with compressed air. I'm not sure if it's noticeable in the picture but that silicone tack on the walls of the spark plug positions is present in every spark plug entrance. I've never changed the plugs but the dealer changed them under warranty 1 month after I bought my car. Is that normal?
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Joined: Aug 2004
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From: Detroit Area
W203 C230, W210 E350, W166 ML63
Here are some pictures of the hose that is disconnected and the clamp that I found at the bottom of my engine.
Last edited by PeteyV; Apr 8, 2015 at 10:49 AM.
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From: New Joisey
13 Jeep JKU Sahara w/4" lift Kit & the works,2015 Toyota Sienna XLE,2013 Hyundai Sonata Hybrid
Slide the black pipe install the clamp and slide the black pipe on making sure the red exposed thing is not visible. Look at the small slit on the black hose and the red thing, they both have a slit. those slits need to match up and the black pipe needs to be pushed all the way up, then tighten the clamp. Hopefully this will fix the issues that you are having.
Javvy
Javvy
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Joined: Sep 2011
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From: Austin, TX
2005 C230K(sold), Mk7 Jetta
Looks suspicious. Looks like the dealership did that on purpose to sell you a new supercharger?
That pipe does not need to be disconnected at all when changing the belt.
That pipe does not need to be disconnected at all when changing the belt.
Thread Starter
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Joined: Aug 2004
Posts: 791
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From: Detroit Area
W203 C230, W210 E350, W166 ML63
I wouldn't doubt it. They also said they would change my rear tail light bulb because it was burned out for $30. Only thing is I have the aftermarket LED S-Class style tail lights.... I asked them if they even looked to see if it was actually out and the SA told me that he would talk to the tech. When I had my repair work done they called me to ask if my windshield wipers were working when I brought my car in.... Yes, yes they were.
Thread Starter
Super Member
Joined: Aug 2004
Posts: 791
Likes: 37
From: Detroit Area
W203 C230, W210 E350, W166 ML63
Reattached the hose and applied the clamp. Everything works great now and I cleared the CEL. It has yet to come back on so I hope that it stays that way. One question though... When I was fitting that hose back into the opening there was lots of oil on the underside of the opening.. I cleaned it up and I will check again to see if it comes back but I'm hoping I don't have leaky cams or something worse. I do remember that I got an oil change from the dealer in January and they spilled oil on the engine and did not even clean it up. Might have got there from that time.
