Hi guys/gals,

Wanted to post here for more visibility in regards to an issue I have been having with my 2007 SL55 93k miles. Car is very rough on cold starts and idles almost perfectly when warmed up. Always had symptoms of a small vacuum leak where when decelerating at around 2k RPM the rpm would slightly bounce between 2k-2200 then go down and same with around 1k-1200 then go down smooth. I tried getting a Eurocharged tune and the CEL would pop up within 10 miles for p0505. Jerry tried sending multiple files and the issue would come up right away (same code). I have since had no tune and I just got the same CEL pop up. The car sometimes has a whining noise at low RPMs then goes away when you turn it off and restart. I completely removed the intake manifolds to verify all the hoses are plugged in and nothing is loose and all is good. Lately, I have heard a very loud constant whistle come from the TB and it will go away when accelerating or tapping the gas pedal and sometimes come back. There has been two times where the car would just crank and not start, but doing attempting to start it the second time starts it up right away (bad crank sensor?)
Just now, I used the iCarsoft and did the ETC (Electronic throttle control system) reset and the CEL went away on its own. This leads me to believe it is TB related? I have noticed absolute throttle position in drive goes from 1.6 to .8 and occasionally will even dip to .4


Here are some videos:



Here are the freeze frames from the CEL with vehicle in Drive:
short term fuel trim b1= .8%
long term fuel trim b1= 5.5%
short term fuel trim b2= 1.6%
long term fuel trim b2= 6.3%
intake manifold absolute pressure= 38 kPa
engine speed 450 rpm (looks low car usually idles at around 550)
ignition timing advance for #1 cylinder= -9.0
Intake air temp= 36C
Absolute Throttle position= 1.2%


Here were live frames I captured for a few seconds each: (first shown in park // followed by drive)

short term fuel trim b1= -4.7 to 3 // -3 to .8
long term fuel trim b1= 7% this was constant
short term fuel trim b2= -25% to -11% // -16.4% to -11.7%
long term fuel trim b2= 7% this was constant
intake manifold absolute pressure= 32-33 kPa // 37-38 kPa
engine speed 640-680rpm // 540-556rpm
ignition timing advance for #1 cylinder= -13 to -9 // -13.5 to -9
Absolute Throttle position= .8% // .8%
Oxygen sensor output voltage (b1-s1) -.8 to 1.6 // .080 to .78
short term fuel trim(b1-s1) -3.1 to 2.3 // -2.3 to .8
oxygen sensor output voltage (b1-s2) .075v to .175v // .090 to .170
short term fuel trim (b1-s2) 99.2% this stayed constant
oxygen sensor output voltage (b2-s1) .070 to .735v // .095 to .745
short term fuel trim (b2-s1) -11.6 to 1.6 // -14.7 to -10.9
oxygen sensor output voltage (b2-s2) .38 to .545v // .740 to .750


Bought the car 4 months ago so far I have done:

new engine + trans mounts
new plugs and valve cover gaskets
new breather hoses
new IC pump
fuel filter
fuel pressure sensor+ upgraded harness
new y pipe (mine was zip tied on) car has 80mm TB stock
new (used) pedal
cleaned TB (did not remove)
diff service
trans service
rear main seal
PLM XL heat exchanger
5 piece aluminum pulleys
83mm SC pulley

For maintenance sake, I will be changing the MAP sensor and IAT sensor and replacing the gaskets under the intake manifolds (getting them powdercoated). I dont think any of this will have any effect on my issues. I am hoping it is not a bad TB, but I am leading to believe that is the case. I will probably have to do a smoke test once I get the MAP and IAT sensor in just to be safe. Are there any other ideas based on what you guys are seeing?

Thank you very much for your time, any help or ideas are greatly appreciated.

 

There are two connections on the back side if the intake/supercharger (nearby the throttle body) which tend to leak. One is a plastic plug, the other one is a small aluminum tube.

Actually there's no better thing for vacuum leaks than smoke test and I would reccomend t before buying any stuff. I saved myself whole weeks of searching for a lot of small leaks on my last BMW and I'd never try to fight leaks without a smoke test anymore.

Actually its pretty easy to do. Made a smoke tester of this type. It does magic.




You can do it even easier

 

Thank you for the reply! I definitely checked the common leak spots, but have yet to do a smoke test. Just ordered some gaskets and things needed when removing intake manifolds (getting them powder coated) so will run a smoke test when I get everything back in. Do you have any suggestions as best place to plug in the smoke machine?

 

I did remove the whole plastic intake up to throttle and then i did put a rubber/vinyl/nitril handglove on the throttle body. Made hole in the middle finger and attached my smoke hose to it with some insulation tape.

 

We used to use throttle body cleaner and spray around the suspect areas while it is idling, if it idled up when you spray a certain spot then that is the culprit, good for picking up pin holes etc that only show up under vacuum.

Inlet manifold gaskets were common as they cool down they open up when they are warm they expand etc

 

i tried brake cleaner and got no surges in idle wherever I sprayed unfortunately

 

I dont think brake cleaner has the same octane as throttle body or carb cleaner

 

Well actually almost every spray which catches on fire will work here.

Two examples:
Cockpit spray of one specific brand is most commonly used "starting fluid" in my country.
Hair spray was the best fuel for our "potato guns" when we built them back in the days.

 

Does anybody know If the big hose from the air filter box y-pipe that attaches to the driver valve cover is detached, will it throw the P0505 aswell?

 

Ok so I took off the manifolds and checked everything here are some pictures:



The metal tube everyone talks about was in firmly, however there is a rubber grommet it goes into and that is a little loose? There is a very small gap between the grommet and the back of the SC , but There is no way to push in the rubber grommet in any more

This breather hose wasn’t in all the way but the clamp was on there tight and don’t see any way it was leaking

Did the IAT sensor while I was at it, very easy

Replaced the rubber pieces that the intake manifolds go into just in case

 

 

Definitely use a smoke machine! I ended up using it and found some small leaks! Im glad i bought one.

 

Fixed!

after a a few shops and a professional smoke test there was a leak coming from the supercharger gasket (SC had to be fully removed)

throttle position at idle is over 2% and 3% in park now. No noise, drives great!

 

 

hi @Amir_AMG


I was wondering if you can help me out with a part number. I upgraded my regular 74mm E55 tb to 80mm (like 07/08 SLs) and trying to find this hose part number. Its from 80mm supercharger snout (0912) to a crank hose.
On a regular e55 big crank vent hose (valve to valve covers) has a nipple in the middle which plugs direct into 74mm TB. But SL55 80mm does not have a hole to plug in. I am guessing its another hose which plugs into 0912 supercharger snout b/c its has a hole for a vacuum (our 74mm supercharger snouts have a plastic plug which blocks it but not 80mm snout). here is your pic,

 

143 is part number 113-010-05-82

 

thank you.
Few dealers I called swear there is only 1 crankcase hose. Clearly there are two. Pic is the one I have but the one ending 05 82 must be for those special years. Thanks again!

 

sorry to bring very old thread back to life, where did you got to get smoke test?

 

took it to a local mechanic