E39 520D Minor Power Loss from day to day. MAF, Vacuum, Turbo replaced. Air intake Cleaned. SOLVED -> Dirty Map Sensor
I am almost done with my E39 520D, but there is one minor issue still bothering me.
"
There are days i feel all those 136 Horses and my car is running so well,Fuel efficiency is great. Other days the car still goes but it feels like i am short 10-15 horses and Fuel efficiency is not that good anymore, It feels like my E39 is lazy and "drinks" more so to say :silly.
Bassicly it comes down to this:
On 'good' days: 136 HP and when i drive 120 KM/H the fuel Needle is steady at 4L/100KM
On 'lazy' days: 120 Hp and when i drive 120 KM/H the fuel Needle is steady at 5L/100KM
Sometimes i drive 30 or more kilometers while the Car is 'Lazy' and after that it suddenly wakes up and really goes. It is really noticeable when i have to go somewhere and i use the highway, on the way there my fuel consumption is aprox 1L higher per 100 KM as on the way back. (In Holland everything is Flat, so that is not an issue). Other days it Runs great from the start, However when the car runs great it never goes to being lazy! It only happens the other way around. From Lazy to Good
I did the following things to try and fix this problem
- New turbocharger (old one was about to go)
- New MAF (Pierburg 7.22684.09.0)
- Cleaned entire air intake: EGR, Pipes, Intercooler, Inlet Manifold
- Cleaned the original Pressure Converter (Turbo ) outside Filter and punctured the inside Filter
- Replaced the pressure converter by a spare one (not new)-> Cleaned the outside Filter and punctured the inside Filter
- Replaced all the vacuum lines
- Closed EGR and even took out the pressure converter at that side so closed off the vacuum lead at the main vacuum hose (something like number 7)
After doing all this in noticed an increase in performance in both the "Good" & "Lazy" moods, however the minor power loss from time to time stays. I have checked from fault codes, however i just get one for Exhaust Gas Re-circulation, which is normal as that one is closed.
I assume it is not an mechanical issue and suspect some sensor or signal to be the problem in my case. Any ideas?
There are two things which of which i am thinking of however i am not sure:
- The spare pressure converter i installed at the turbo is not functioning very well, however the actuator arm is moving as it should and even if it would not work a 100%, does this justify the higher Fuel consumption and could it suddenly "start to work" after 30-40-50 Km?
- MAP sensor ? Could this cause the problem. From what i read it should give a fault code if faulty. (none given)
Maybe there is another sensor i am missing?
I am almost done with my E39 520D, but there is one minor issue still bothering me.
"
There are days i feel all those 136 Horses and my car is running so well,Fuel efficiency is great. Other days the car still goes but it feels like i am short 10-15 horses and Fuel efficiency is not that good anymore, It feels like my E39 is lazy and "drinks" more so to say :silly.
Bassicly it comes down to this:
On 'good' days: 136 HP and when i drive 120 KM/H the fuel Needle is steady at 4L/100KM
On 'lazy' days: 120 Hp and when i drive 120 KM/H the fuel Needle is steady at 5L/100KM
Sometimes i drive 30 or more kilometers while the Car is 'Lazy' and after that it suddenly wakes up and really goes. It is really noticeable when i have to go somewhere and i use the highway, on the way there my fuel consumption is aprox 1L higher per 100 KM as on the way back. (In Holland everything is Flat, so that is not an issue). Other days it Runs great from the start, However when the car runs great it never goes to being lazy! It only happens the other way around. From Lazy to Good
I did the following things to try and fix this problem
- New turbocharger (old one was about to go)
- New MAF (Pierburg 7.22684.09.0)
- Cleaned entire air intake: EGR, Pipes, Intercooler, Inlet Manifold
- Cleaned the original Pressure Converter (Turbo ) outside Filter and punctured the inside Filter
- Replaced the pressure converter by a spare one (not new)-> Cleaned the outside Filter and punctured the inside Filter
- Replaced all the vacuum lines
- Closed EGR and even took out the pressure converter at that side so closed off the vacuum lead at the main vacuum hose (something like number 7)
After doing all this in noticed an increase in performance in both the "Good" & "Lazy" moods, however the minor power loss from time to time stays. I have checked from fault codes, however i just get one for Exhaust Gas Re-circulation, which is normal as that one is closed.
I assume it is not an mechanical issue and suspect some sensor or signal to be the problem in my case. Any ideas?
There are two things which of which i am thinking of however i am not sure:
- The spare pressure converter i installed at the turbo is not functioning very well, however the actuator arm is moving as it should and even if it would not work a 100%, does this justify the higher Fuel consumption and could it suddenly "start to work" after 30-40-50 Km?
- MAP sensor ? Could this cause the problem. From what i read it should give a fault code if faulty. (none given)
Maybe there is another sensor i am missing?