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mercedes 71 280sl. Porsche 930 . Ducati mh900 and ps1000
turbo cuts out...
hi guys car is a 07 gl320
when engine is hot the turbo will stop working . if I restart the car all is well for a while
last march I had the same problem with a cel for Diesel Particulate Filter Differential Presure Sensor. I replaced the sensor and all was god
now same problem but no code with star...
what can this be?
thanks
Hmm Maybe its out of "Turbo Rocket Fluid" yes that is a real thing!
It would be strange for the turbo to stop working when the engine gets hot. Maybe it feels like it stopped working? Because as oil warms up it becomes thinner and then provides proper better lubrication that in theory help the turbo spin more freely. If you look at the workings of a turbo the turbo section which passes exhaust gasses are connected via a shaft to compressor. Thus for the turbo to really stop working would mean that something happens for the shaft to stop turning and the compressor wheel from sucking in air and compressing it.
What most likely is happening is that turbo was never really working, or the wastegate actuator is busted or allowing exhaust gas to escape thus slowing the velocity of the turbine wheel and thus not allowing the turbo to build boost. Another option is that compressor wheel is damaged or etc.
The real way to know if you are getting any boost is to look at the computer or connect a boost gauge.
An easy prelim check is to remove the engine cover and have someone rev the engine while you observe if the actuator arm is moving. If it's not moving, then check to see if it's sticking or if the actuator itself is not working > disconnect the C-clip on the arm, and see if you can move it freely. You can then also rev the engine and see if the actuator works when not connected to the turbo. If confirmed that the actuator is not working, then you can try to fix it or send it out to get repaired. The dealer does not sell are repair this item separate from the turbo.
As far as failing when the engine is hot, this is quite plausible because the terminals are connected to the circuit board by very fine fusel links. It would appear that they tend to deteriorate over time probably due to heat and vibration. When the engine is hot, and therefore also the actuator, the links will have poorer conductivity and may not be able to supply the proper voltage and current to the circuit board.
In my case, when looking inside the actuator, everything looked good until I tested the resistance on all of the links and found that one was bad. A light tap with the multimeter lead caused this wire to actually separate from the circuit board. A quick re-solder and I haven't had a problem since.
Pass side attached to turbo. Make sure you blip the throttle in quick succession to build some load on the engine as if you just freely rev there will be no boost.
Hope someone can point me in the right direction. I have checked the VGT canes and they move freely. I have check the actuator for movement when reving the engine and it moves. I have had a shop smoke test the intake and they found no leaks.
The car car goes into LHM at constant throttle while under a moderate or more load, like going up a small hill. At higher RPM it's fine. Over 80 mph it's fine.
Anything else I can check before I spend the money to take it to the dealer? I'm sure they will first suggest a brand new turbo and I don't want to have a fight if I don't have to.
P0544
I am going to check the exhaust sensors to see if they need to be cleaned.
Reductant heater B control circuit
I am going to check the connections on the Reductant heater. I'm hoping this one is just a bad connection cause I have looked and it can be expensive to replace.
P0299
Often times it will go into LHM and not throw the underboost code. Shutting off the engine and starting it back up brings it back to life.
I have read some potential causes but as an engineer I want to know root cause and failure mode before I start shotgunning parts.
It kinda sounds like it's exhaust related. Check the exhaust temp sensors and the pressure lines that run to the differential pressure sensor - there could be a leak or a blockage.
BTW, I did a 40,000km test with a cetane booster on a big rig: no benefit in fuel economy however the number of DPF regens were cut down by 2/3. So, if you find a blockage, you might want to consider a fuel additive to prevent future issues.
I used to run additives in my 7.3L power stroke with every tank after the introduction of ULSD. The 7.3L with the HEUI injectors ran terrible with ULSD.
Any brands you recommend? We have some SoCal local products that I have used but it has been a few years.
I am am also considering a water injection setup to help with all the EGR mess. I've had friends who see positive results on newer EGR equipped light duty diesels.
I use the Opti-lube Boost. Its 70% 2-EHN, which I dose at 300mL per 75L of fuel. That's much higher than their recommendations, but it's the concentration that provides the theoretical 10-point cetane number increase. I also put in the recommended dose of their XL fuel lubricant.
So I don't have the time right now to work on my R. I took it to a local shop and they found a cracked exhaust manifold. They found a TSB for this and talked to Mercedes.
Mercedes is telling them that both manifolds need to be replaced, only one is obviously cracked, and the turbo needs to be replaced. They are saying the turbo is slowing down and causing too much heat that results in cracks.
I'm not buying it. That doesn't make sense unless the turbo is a bad design, or the exhaust manifolds are cheap and crappy. Either way replacing them with the same thing will just result in the same problem.
I am having them replace the cracked manifold. If I need to replace the turbo I can do that. This car has 125,000 miles on it. If I can get another 80,000 I will be happy.
I am going to post this in another post for more comments.
Exhaust leak before turbo could cause the "turbo cutting out" issue, but cracked manifold because turbo is slowing down and causing too much heat is a complete BS.
Does make me wish for some better replacement manifolds and turbo. I know this is not as common on the MB Bluetec. I had all kinds of options when I had a Ford F350 with the 7.3L Powerstroke.
10-16-2016, 12:33 AM
is a complete BS.
