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Trying to diagnose this as much as possible on my own without taking it to a shop. I have a little Artidiag500 scanner that shows reasonable data. Just not everything. Code seems almost random, goes away when cleared but comes back ever so often. Now? It seems to come back relatively quick when cleared. Car isn't terrible on power, to most they wouldn't recognize a difference. But I can tell a big difference. Passenger side rod of the actuator shakes back and forth in almost a rattle pattern. Driver side rod is completely still on startup. I've read so many different fixes and issues, I'm not sure where to start. Handy with tools myself. Any help is appreciated
Thanks...that's a lot of info though lol. But I read through it. Seems like mine may have a leak at the wastegate? Which I mean, is kinda what I already suspected. The other side isn't shaking like that. Doesn't move on startup at all. Some said they swapped out the vacuum actuator, there a write up on how to do so? All I see are people testing the solenoid but not actually removing the vacuum actuator and swapping it out to see if the issue resolved itself. With mine being so intermittent, I'm assuming it isn't bad yet. Though it is becoming more prevalent so I'm trying to get ahead of it before it does.
I just find it odd that the P0299 code says turbo 1 but the turbo on the passenger side is the one that's shaking. Thought turbo 1 was on the driver side
If wastegate itself leaking = New Turbocharger
I have not seen wastegate only repair kit discussed for M276 3.0 or M278 , but available for other cars like BMW.
you wrote: Passenger side rod of the actuator shakes back and forth in almost a rattle pattern.
That does not mean wastegate is bad. Minor rattling is common as there is play there.
Take a look at the boost control solenoid first...........
If wastegate itself leaking = New Turbocharger
I have not seen wastegate only repair kit discussed for M276 3.0 or M278 , but available for other cars like BMW.
you wrote: Passenger side rod of the actuator shakes back and forth in almost a rattle pattern.
That does not mean wastegate is bad. Minor rattling is common as there is play there.
Take a look at the boost control solenoid first...........
Well darn. Looks like I'll have to grab one of those then. And rattling doesn't mean wastegate is bad...that's good to hear. Didn't know rattling was normal behavior. However...the code says turbo 1, but the passenger side is the only one rattling. Driver's side doesn't move. I pray it isn't a new turbo needed. Last thing I need right now. Looks like I may start with the boost control solenoid. And possibly the mightvac
If wastegate itself leaking = New Turbocharger
I have not seen wastegate only repair kit discussed for M276 3.0 or M278 , but available for other cars like BMW.
you wrote: Passenger side rod of the actuator shakes back and forth in almost a rattle pattern.
That does not mean wastegate is bad. Minor rattling is common as there is play there.
Take a look at the boost control solenoid first...........
Also, that link...the video of the wastegate actuator shaking back n forth and he says is this normal? That's exactly how mine looks
01. Vacuum actuator , that round thingy not able to pull to maximum to close wastegate properly and hence u loose boost.
This vacuum actuator also not sold separately by MB but aftermarket one still available.
It can have lots of oil inside the membrane and fail.
Above video is for M157 and those AMG engine, but it is the same know-how.
02. The small vacuum hoses powering the suction power of vacuum actuator, mild leaking. So not enough vacuum to pull the vacuum actuator.
There is a Tee fitting which split single suction source from boost solenoid towards 2 of the vacuum actuator .
03. The boost solenoid not opening maximum and somehow one bank get less vacuum power than the other bank.
From vacuum pump there is a small hose to this boost solenoid. It can leak too.
04. Leak, boosted air leak at all air path from turbo to aftercooler to intake manifold.
This is the tricky part not only it is difficult to find boosted air leak if small leak, its a lot of work.
Two turbos boosted air, will become a single boosted air source at the aftercooler and also at the intake manifold.
The so called turbo boost sensor is actually reading combine boost from both turbos and as far as I know, there is no dedicated turbo boost sensor per Bank/Turbo.
The only way the computer can know one of the turbo is bad is by sensing the intake air sensor, which each bank has 1 at the air filter housing.
The ECM has tables to compare that at X boost, there will be pressure reduction at each air filter housing due to suction effect of air into turbos.
So, technically if your Bank 1 air pressure sensor at the air filter housing has intermittent issue and not registering proper values, ECM can misread that as low boost because NOT ENOUGH powerful low suction occurred.
Also, that link...the video of the wastegate actuator shaking back n forth and he says is this normal? That's exactly how mine looks
No, shaky rod doing oscillation forward and back is no normal. It would stay nice deep pulling back steady.
The rattle noise is another story and acceptable up to a point. The rattle comes from the end of the vacuum actuator rod towards the waster gate shaft. There is minor play there on purpose.
The P0299 most of the time is an issue with the actual physical wastegate not closing all the way. This is why it shakes, it's loose. Turbo bank 1 is passenger side and turbo bank 2 is driver's side. Remove the Catalytic converter assembly and visually check that the wastegate is properly working. If you find the wastegate is the issue, new turbo assembly will be needed.
If you can get to the wastegate rod with your hand, you should be able to pull it. It should have resistance.( regardless of a bad diaphragm)You would also be able to hear the puck on the turbine slap closes when you let go. There should be a little play because you do not want that assembly binding. You can buy good aftermarket wastegates all day long if that's your issue. Testing it with regulated shop air is also an option. Since there's two you test both.
01. Vacuum actuator , that round thingy not able to pull to maximum to close wastegate properly and hence u loose boost.
This vacuum actuator also not sold separately by MB but aftermarket one still available.
It can have lots of oil inside the membrane and fail. https://youtu.be/GanCodyFXdM
Above video is for M157 and those AMG engine, but it is the same know-how.
02. The small vacuum hoses powering the suction power of vacuum actuator, mild leaking. So not enough vacuum to pull the vacuum actuator.
There is a Tee fitting which split single suction source from boost solenoid towards 2 of the vacuum actuator .
03. The boost solenoid not opening maximum and somehow one bank get less vacuum power than the other bank.
From vacuum pump there is a small hose to this boost solenoid. It can leak too.
04. Leak, boosted air leak at all air path from turbo to aftercooler to intake manifold.
This is the tricky part not only it is difficult to find boosted air leak if small leak, its a lot of work.
Two turbos boosted air, will become a single boosted air source at the aftercooler and also at the intake manifold.
The so called turbo boost sensor is actually reading combine boost from both turbos and as far as I know, there is no dedicated turbo boost sensor per Bank/Turbo.
The only way the computer can know one of the turbo is bad is by sensing the intake air sensor, which each bank has 1 at the air filter housing.
The ECM has tables to compare that at X boost, there will be pressure reduction at each air filter housing due to suction effect of air into turbos.
So, technically if your Bank 1 air pressure sensor at the air filter housing has intermittent issue and not registering proper values, ECM can misread that as low boost because NOT ENOUGH powerful low suction occurred.
Attached M278 tech manual.
Happy troubleshooting
I'm thinking about just getting the vacuum tester thingy but after a couple of advice, maybe I should just shoot for an aftermarket vacuum actuator? See if that fixes it? Or maybe I should try the solenoid first?
Originally Posted by chassis
Shaking / rattling boost rod sounds like the boost vacuum actuator is kaput.
Yeah I'm considering just replacing it with an aftermarket one and seeing how that does.
Originally Posted by MBENZTECH
The P0299 most of the time is an issue with the actual physical wastegate not closing all the way. This is why it shakes, it's loose. Turbo bank 1 is passenger side and turbo bank 2 is driver's side. Remove the Catalytic converter assembly and visually check that the wastegate is properly working. If you find the wastegate is the issue, new turbo assembly will be needed.
Ah, had my turbos mixed up then. I certainly hope a new turbo assy is not needed in this case. That'll be hell I'm sure. At that rate, I'd either slap some M157 turbos on it or something from weistec. Can the cat converter assy be removed from the top? I don't have access to a lift.
Originally Posted by Dane500
If you can get to the wastegate rod with your hand, you should be able to pull it. It should have resistance.( regardless of a bad diaphragm)You would also be able to hear the puck on the turbine slap closes when you let go. There should be a little play because you do not want that assembly binding. You can buy good aftermarket wastegates all day long if that's your issue. Testing it with regulated shop air is also an option. Since there's two you test both.
Don't have access to shop air. But I can reach the rod and gently see what type of resistance it has I suppose. See if I hear anything or not. Ill even look into an aftermarket wastegate, but an earlier reply stated if it was the wastegate, I'd have to replace the entire turbo assy?
No, shaky rod doing oscillation forward and back is no normal. It would stay nice deep pulling back steady.
The rattle noise is another story and acceptable up to a point. The rattle comes from the end of the vacuum actuator rod towards the waster gate shaft. There is minor play there on purpose.
Also, maybe I worded it wrong. When I said rattle...I was referring to the way it moves...not the sound it makes. Shakes in a rattle pattern...like back and forth really fast
Checked the movement with my hand. The rod doesn't move much at all. It moves..but it does have a decent amount of resistance there. Feels solid and stiff but moves fine. Does that potentially rule anything out? Also checked the routing and the hoses, don't see anything obvious. The tool would obviously be better suited to check these things though. Question is, does it check each individual hose for vacuum leak? Because if so, I may start there.
No, shaky rod doing oscillation forward and back is no normal. It would stay nice deep pulling back steady.
The rattle noise is another story and acceptable up to a point. The rattle comes from the end of the vacuum actuator rod towards the waster gate shaft. There is minor play there on purpose.
Got that Vacuum pump tester coming thursday. Ill be able to really check each hose and see whats leaking and whats not. Really considering just ordering the Boost actuator solenoid though. at over 90k miles, its probably time anyway. The CEL comes on for a while and goes off for a while, so it seems to be intermittent unless i romp on the gas, then it comes on immediately. FCP euro a good place to get the solenoid?
Do the vacuum test first. If you boost control solenoid is the issue, both your turbo vacuum actuatosr will be effected as this solenoid is the single source of vacuum control with Tee fitting to
connect to both vacuum actuators.
Do the vacuum test first. If you boost control solenoid is the issue, both your turbo vacuum actuatosr will be effected as this solenoid is the single source of vacuum control with Tee fitting to
connect to both vacuum actuators.
Alright, I'll get my eyes on it tomorrow once the test comes in. Not exactly sure how to test it but I'm sure there's some kinda instructions somewhere
Do the vacuum test first. If you boost control solenoid is the issue, both your turbo vacuum actuatosr will be effected as this solenoid is the single source of vacuum control with Tee fitting to
connect to both vacuum actuators.
Got the kit. About to start testing now. Not sure where the instructions are for testing. I'll look over the post you sent and see
@S-Prihadi yeah I'm not exactly sure what I should be doing here. I understand the concept of testing vacuum. But not actual step by step. I imagine the car has to be running, but does it have to be running just to check hose condition? Which end should I remove to check the boost solenoid?
Hooked the line up to the passenger turbo wastegate. Applied vacuum to see if rod moved and held. Once it moved at around 7psi and let it sit for a couple mins. It held. So there doesn't appear to be any leakage from the wastegate or vacuum actuator itself. Only other thing left to test are the hoses and the boost solenoid.
Tested the hoses with the vacuum tool. No drop in vacuum or pressure. Seems like it's narrowed down to the solenoid.
Put a three way T- hose on the solenoid turbo side, vacuum tool with gauge in the middle, and turbo Y fitting on the other side. So acts as a gauge to monitor vacuum pressure. Set the tool to vacuum and started the car up. Vacuum needle seems to be just bouncing constantly. Almost in the same rhythm as the shaking from the actuator.
Switched them around this time. 3 way nozzle from Solenoid, to gauge, to hose that goes on the bottom inlet for vacuum from engine. Same thing. Bouncing around. My thinking is that the solenoid is bad...or going bad...however.......
This time plugged all hoses back up, and simply connected the gauge to the hose that goes to engine vacuum. One way line. Started it up and it's bouncing still. Slower....but still bouncing. So could that mean there's a leak in the hose coming from engine vacuum?
Did a bit more searching around. Seems like it could be that hose that runs from the solenoid to the vacuum pump. However it's pretty stuck on and impossible for me to remove to test it without damaging it. So no sure fire way to determine if it's the vacuum pump itself or not. However, searching led me to a guy that fixed this exact problem. Instead of removing and replacing the hose I spoke of, he replaced the check valve that the hose is attached to with the Torx bit. That'll more than likely be my first mode of operation. Replace that and see what happens.
Although....after some spirited driving tonight and multiple drive cycles.....there is no CEL and power is back 100%. Could be just a fluke however as the rod still shakes. Could very well have been a loose hose though. I'll proceed with the purchase of the check valve. Apparently some in the UK on the fords are the exact same part. For all of $20. I'll replace that AND the vacuum hose and see what that does. I believe shipping is a week or so
If you hook directly your vacuum pump hose to turbo vacuum actuator and suck it down, and that vacuum actuator both are good by staying deep pulled = you are gold because other issue is less difficult to access or fix.
I know M278 is more crowded with the aftercooler being on top of V bank and is more hassle than my M276 3.0 Turbo
03-03-2023, 04:09 PM
