Need help - weird issue
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Super Member
Joined: Jan 2007
Posts: 979
Likes: 38
From: South Africa
2018 E63s AMG (Current) 2011 CL63 AMG (Sold) 2005 CLS55 AMG (Sold) 2004 C32 AMG (Sold)
Need help - weird issue
Hi all, so after removing the SC and intercooler to install a meth kit I had a low boost issue. Where under WOT meth kit off of course, I was only showing 1.5psi boost. Thinking it was possibly the MAP sensor I replaced it with the OEM MAP sensor bought from Merc. Part number is 0051535028. Now to replace that sensor I had to lift the SC again, pain in the ***. However now when I start the car I can't even drive it. The car idles rough and the afr is in the 9's at idle!!! Even the manifold pressure seems very high for idle just below boosting values. Have they sold me the wrong MAP sensor? I doubt it as I got if from Mercedes with my VIN number. Checked for codes through DAS and nothing comes up. Any ideas gents?
Super Member
Joined: Jun 2017
Posts: 899
Likes: 140
2005 E55
Hi all, so after removing the SC and intercooler to install a meth kit I had a low boost issue. Where under WOT meth kit off of course, I was only showing 1.5psi boost. Thinking it was possibly the MAP sensor I replaced it with the OEM MAP sensor bought from Merc. Part number is 0051535028. Now to replace that sensor I had to lift the SC again, pain in the ***. However now when I start the car I can't even drive it. The car idles rough and the afr is in the 9's at idle!!! Even the manifold pressure seems very high for idle just below boosting values. Have they sold me the wrong MAP sensor? I doubt it as I got if from Mercedes with my VIN number. Checked for codes through DAS and nothing comes up. Any ideas gents?
Throttle body plug from the harness should have a strip of blue tape on it I believe.
Thread Starter
Super Member
Joined: Jan 2007
Posts: 979
Likes: 38
From: South Africa
2018 E63s AMG (Current) 2011 CL63 AMG (Sold) 2005 CLS55 AMG (Sold) 2004 C32 AMG (Sold)
Anyway good news after a very frustrating week pulling the SC off 3 times checking everything, replacing sensors etc I have found the problem.
So the newest issue which was after replacing the MAP sensor with a new OE part, number posted above, either that sensor is faulty new from the factory or it is the wrong replacement MAP sensor for this car. What happened with this new MAP sensor was at idle the car was in the 9's afr and could not drive it at all, after revving it and it falls back to idle the car nearly dies and throws a big backfire sounded very Nascar but undriveable, so I decided to swap back to my original MAP sensor that was on the car and that immediately sorted out my idle issue and things were back to normal.
On test drive I have my original issue again of a big boost leak somewhere only showing 1.5psi boost at wot... Very frustrating couldn't find a leak anywhere..
I decided tonight to just switch the meth kit on and see what happens... Floor it, and my goodness car takes off like a rocket... So I can only assume the solenoid in the meth kit has failed open, as when the system is powered up the SC boost is back to normal, system switched off and boost leak is there... Bloody meth kit solenoid is where I am putting my money at tomorrow, will have to confirm 100% in the morning by plugging the nozzle line to make sure I am right. What a learning experience this whole project has been...
Last edited by C32owner; Oct 5, 2017 at 01:26 PM.
Super Member
Joined: Jun 2017
Posts: 899
Likes: 140
2005 E55
Hi mate, so to answer you nope didn't get the plugs mixed up, I marked them specifically.
Anyway good news after a very frustrating week pulling the SC off 3 times checking everything, replacing sensors etc I have found the problem.
So the newest issue which was after replacing the MAP sensor with a new OE part, number posted above, either that sensor is faulty new from the factory or it is the wrong replacement MAP sensor for this car. What happened with this new MAP sensor was at idle the car was in the 9's afr and could not drive it at all, after revving it and it falls back to idle the car nearly dies and throws a big backfire sounded very Nascar but undriveable, so I decided to swap back to my original MAP sensor that was on the car and that immediately sorted out my idle issue and things were back to normal.
On test drive I have my original issue again of a big boost leak somewhere only showing 1.5psi boost at wot... Very frustrating couldn't find a leak anywhere..
I decided tonight to just switch the meth kit on and see what happens... Floor it, and my goodness car takes off like a rocket... So I can only assume the solenoid in the meth kit has failed open, as when the system is powered up the SC boost is back to normal, system switched off and boost leak is there... Bloody meth kit solenoid is where I am putting my money at tomorrow, will have to confirm 100% in the morning by plugging the nozzle line to make sure I am right. What a learning experience this whole project has been...
Anyway good news after a very frustrating week pulling the SC off 3 times checking everything, replacing sensors etc I have found the problem.
So the newest issue which was after replacing the MAP sensor with a new OE part, number posted above, either that sensor is faulty new from the factory or it is the wrong replacement MAP sensor for this car. What happened with this new MAP sensor was at idle the car was in the 9's afr and could not drive it at all, after revving it and it falls back to idle the car nearly dies and throws a big backfire sounded very Nascar but undriveable, so I decided to swap back to my original MAP sensor that was on the car and that immediately sorted out my idle issue and things were back to normal.
On test drive I have my original issue again of a big boost leak somewhere only showing 1.5psi boost at wot... Very frustrating couldn't find a leak anywhere..
I decided tonight to just switch the meth kit on and see what happens... Floor it, and my goodness car takes off like a rocket... So I can only assume the solenoid in the meth kit has failed open, as when the system is powered up the SC boost is back to normal, system switched off and boost leak is there... Bloody meth kit solenoid is where I am putting my money at tomorrow, will have to confirm 100% in the morning by plugging the nozzle line to make sure I am right. What a learning experience this whole project has been...
Thread Starter
Super Member
Joined: Jan 2007
Posts: 979
Likes: 38
From: South Africa
2018 E63s AMG (Current) 2011 CL63 AMG (Sold) 2005 CLS55 AMG (Sold) 2004 C32 AMG (Sold)
Lol I hear you, what a mission, and yes that thing weighs a ton, definitely 2 people to lift it out.
Can't wait to do some testing and checking all nozzles and different setups
Can't wait to do some testing and checking all nozzles and different setups
