Which part are you referring to that was only $30? The cheapest I have found the A0081535428 Peirburg boost pressure actuator is about $70.

 

Definitely a Garrett. The junk yard mentioned this came off of a S500. I don't think the wastegate vacuum actuator would work. I believe the length of the rod looks shorter. I would love to upgrade the IHI turbos if they would bolt on. I would need Different charge pipes and downpipes to make this work and tuning. Thoughts?

 

You have to remember, when I bought mine the economy was different, now everything cost about double from 2021

 

If it was an S class in America it would have been a S550 2011 and up. The rod lenght is adjustable, Benz put some (spec'ed) glue to hold it in place. If the shape is the same it should work. The problem with all actuators is the diaphragm, in turns hard as age, and heat is applied. This is why some people with turbos go aftermarket, because you can unscrew the actuator, and put a new diaphragm.

 

Any suggestions for an aftermarket turbo replacement? This place was selling this turbo for $190. They only have the left side. I just need the actuator replaced. The ebay links in this thread are aftermarket actuators from Taiwan. Nothing in the US.

 

Why not check with a turbo shop, to see if you can get the turbos reconditioned, or just the parts you want reconditioned? https://www.ihi-turbo.com/aftermarket

 

I emailed IHI amd tried calling with no response yet. I'm going to see what my options are for a set of turbos. Thank you for all your help. Really appreciate it!

 

Vacuum pump is to test if vacuum actuator leaky or not and what vacuum minimum vacuum level it will need to do a proper pull.
No need Xentry, simply turned on ENGINE and boost pressure actuator should do its job well if it is healthy.
See this thread https://mbworld.org/forums/e-class-w...te-issues.html

Have fun troubleshooting....

 

What's everyone's opinion on buying 2 used turbos with 65k for $1100 total? Still waiting on IHI to contact me to see if the wastegates can be purchased separately.

 

IHI will not respond, you need to check with a vendor.

 

Used with 65K miles . I'd Run fast away. No way to know if the shaft bearings are toast if the units got overheated or the car was modified and caused issues on the turbos Only buy new turbos complete with new actuators. Now if IHI supplied the OEM and you can find a vendor to get those brand new ...go for it Other wise , the a/r might not match nor the spool up be the same. Stay away from chinese sourced "replacement" turbos ....Seriously....

 

I understand and agree with you. I just hate the fact of buying new turbos when mine are fine and I only need one actuator. Spending over 3k on new turbos was not in my to do list lol. Any recommendations on good aftermarket turbos? Still new to the mercedes platform. Switching over from Audi. I usually buy from FCP Euro.

 

Great tech thread. I'm chasing a recurring P0234 error on my M157 engine. This is for Turbo 1 boost too high. I'm wondering if this part could have something to do with that? Maybe the wrong electrical feedback is being sent to the ECU from this controller? The car drives absolutely fine when the light is on. Sometimes it comes back in 1 or 2 drive cycles, sometimes it does not come back for days. I understand the MAP sensor and airbox sensor readings, but I can't figure out where the "Boost Pressure" reading comes from, and it does not seem like there is a separate reading for bank 1 vs. bank 2. I'm guessing the code defaults to "Turbo 1" if there is only 1 sensor reading. I've tried watching the graph of boost pressure and MAP pressure while driving (I know, I should log it) and I don't see any abnormal spikes. I've been able to see enough live data history when the light triggers that it should be evident in the sensor graphs.

I will note that I found oil all the way at the main ECU connector, not a ton. I cleaned that out on both ends while installing new cam sensors and have not seen any oil return at the connections. When I first removed, cleaned, and re-installed the ECU I didn't get the code for about a week. After that it sat at a shop getting the wheels refurbished for 2 weeks, then triggered on the drive home. I disconnected and reconnected the ECU again just to inspect for oil and the code didn't trigger for a couple more days, but now it comes on randomly within a short time or a few days as I clear it each time. My last drive was about 150 miles of highway speeds after clearing and it did not come on. I think I made 1 or 2 short trips after that drive, still no code. It seems to trigger more in just low speed around town driving.

At this point I'm thinking to just replace this controller and the MAP sensor as they are not very expensive. I would replace the sensor for boost pressure if I could figure out where it is.

Any thoughts or info appreciated. Thanks.

 

Actually this is a good question UFO ....

First understand that there are 2 pressure sensors.

One is before throttle body B28/6 and one after throttle body B28/7.
The one after throttle body we usually call it MAP ( Manifold Absolute Pressure) sensor, because indeed it is a the Intake Manifold.
The MAP will read negative suction before turbo boost build up and will read turbo boost once the pressure at the manifold is above ambient or 1 atmosphere, lets just call it 1 BAR and you are at sea level.

However, the turbo air pressure when in boost, occurs/exist between turbo charger>>>aftercoooler>>>throttle body>>Inlet manifold
The blue zone is read by before throttle body B28/6 (upstream)
The red zone is read by after throttle body B28/7 (downstream)

Now, based on my engine computer for M276 3.0, which should be the same as your M278 V-8 in terms of working parameters of so called Turbo Boost watch dog,
funny enough Xentry term for turbo boost is actually before throttle body B28/6
I too was confused at first

I tested by unplugging B28/6 and indeed it read 5V . A 5V means disconnected connector to sensor.


Remember, my engine is an easier view compared to M278 which its aftercooler is at engine V bank and the throttle body is far at the engine rear side not easy to see witthout removing components.
My aftercooler is at engine front crankshaft pulley and throttle body is right after aftercooler and the elephan trunk shaped inlet manifold between aftercooler and the engine computer...simple to see and visualize.

==============

Now, if you so happened already has oil into ECM connector...hhhmm, it can do many funny stuff too.


Hope the information helps.

 

Have you done a full engine bay clean up? There is oil still traveling in there. I already put up the products to use (MB recommends) with non of the 3 engine covers in place.

 

Yes, first thing I did was degrease / wash the engine bay with the covers and air boxes removed, and the rubber insulator pieces off the fuel rails. I sprayed out the connectors for the cam sensors and the ECU with electric cleaner and air. It's been weeks of driving and I have taken out the ECU a few times to check for any further signs of oil in the harness or pins, I haven't found any. Also checked the connectors on the cam adjusters, but they're clean. I changed the coils and found no evidence of oil traveling to any of those.

 

Do the airbox barometric sensors both show the same value? If one is off, it can make the PCM think that the turbo on that bank is over- or under-boosting since boost is calculated as a pressure ratio upstream and downstream of each turbo. Also check your boost control solenoid lines for cracks.

There are 2 MAP sensors - one just before the throttle body and one on the manifold itself (under a cable run). The PCM uses throttle control to modulate load at times (more so with an imperfect tune) and the 2 sensors will show different readings in that case - the manifold sensor will see less boost if the throttle body is being closed by the PCM. Kind of a side tangent...

 

Hey gang, does someone know if the M278 turbos are direct bolt on if installing on my M276? What turbo upgrades are available for the M276 3.0t? I found a nice set off of a M278. Still trying to figure out the low boost issue.

 

Airbox and ambient sensors all show steady values (I think 1 bar). I have only 1 MAP sensor value to display in my scan tool, and 1 "boost pressure" value. I know about the MAP under the top wiring loom, I haven't figured out where the "boost pressure" sensor reading comes from. Now looking at the parts diagram, I see 2 MAP sensors shown. I guess maybe I can reach the top one and see if I unplug it which value goes away. the bottom one looks like a total PITA. Don't even know how to get there, I guess remove the top intake manifold

I haven't been able to log anything with the sensor data streams that looks out of the ordinary. Reading general information about P0234 overboost code, it seems if the code were real the engine should disable turbo and go into limp.

 

OBD2 type scanner see BOOST only when the MAP B28/7 ( after throttle body ) is above 1 atmosphere, which means there is turbo boost.
You need a mid range scanner with MB software, example Autel MS906BT or Xentry Passthru ( naughty one ) to see all pressure sensors reading as per how MB represent it in Xentry.
Minimum get iCarsoft MB V3.0

 

I have Launch X431 V scanner. It's very comprehensive. I can see all the sensor values, run test sequences, etc.

 

This may sound crazy, but I now believe the exhaust modified by the previous owner was causing the over boost code P0234. PO had cut out the center muffler from the exhaust to make it noisy. I don't like to draw that attention, so I found the original mid muffler part on Ebay, and had it installed by the muffler shop to restore stock exhaust as it came. After that was added back, I cleared the code. It's been about a week of driving and has not returned. Hopefully this is resolved. I can only think it has something to do with the back pressure on the turbo system. The mid muffler seems to also act as sort of an X-pipe, mixing the exhaust paths of the 2 banks. The car actually feels more peppy now, drives like a fast Mercedes should, more similar feel to my old E550 with M278.

 

ahhhhhh the code is back again

I'm ordering one of these boost control solenoids in hopes that it fixes something. Pretty cheap and easy.

 

following up, I bought a part off Ebay that was imprinted with one of the matching MB part numbers, logos, and had Pierburg molded into the plastic. It was about $30. That part immediately gave me UNDER boost code. It also looked slightly different in the side area where the little square relief valve is located, it was more round there. I then decided maybe this was a knock-off or factory reject part. I decided to swap the OEM part with the same original part numbmer from my other GL550 (M278) and that ran just fine for about a week, no codes, and it felt like it had more pep in the low end of RPM range. I decided to order the latest transducer with updated compatible part number from a legitimate online OEM parts source. I now have that installed and running great for a couple weeks. I replaced the original one back to my GL550, but that car ran fine with no error codes on my original part from the ML63 with the same number. One thing I found curious about the GL550 is that there is no "boost pressure" reading from the ECM.

I did get a refund from the Ebay seller after describing my trouble. Moral of the story, don't buy cheap ebay parts, even if they do appear to be OEM labeled.

 

Got a little issue with my car. There is a delay in power launching the car off a stop. Massive surge in power around 4000 RPM. My mechanic found no issues with my vacuum pump. I do not have xentry or a windows computer to hook up to my car to check to see if the solenoid is bad. You think the solenoid could be the problem in my scenario?