General turbo going off at 2500rpm

[zugreveles]

I have issue with my stilo 1.9jtd… When i drive on the highway, if i push on the pedal on 4-5 gear, on 2500rpm i get instant engine failure msg and my turbo turns off. Turbo goes on again if i put in neutral then put back in gear, but the problem is still there everytime when i pass 2500rpm. After several times of this sitoation (turbo going on and off like that), there is good chance that turbo will be completely off with engine failure error several days! without turbo, car is so slow and painfull to drive on the highway…

I put the car on fiat diagnostics and we got map sensor error. Replacing with new map sensor does not fix the issue, the problem was still there…

Also, with maf sensor disconnected, the car was the same as before. There was no performance improvements and the problem was still there.

Anyone having this isuue?? what do you think?

 

[Davren]

You had the same problem in July 2019. What did you do to fix it that time?
.

on a highway, when i push hard on the pedal, on 2500 RPM there is always instant power loss (turbo goes off) and engine failure message on dashboard. after that the car is running without turbo and its slow like hell. Then i need to take out from gear and put it back again and turbo goes on again till 2500rpm... on 2500rpm goes off again with that engine failure msg. thats so anoying...

.

 

[zugreveles]

You had the same problem in July 2019. What did you do to fix it that time?
.

.

Never fixed this issue. I fix everything except this.

 

[g8rpi]

Does the MP sensor give sensible readings?
What does the air temperature read?


The ECU cutting boost does sound like a pressure sensor issue.

It's not just the sensor that can cause a "MAP failure" It could be a bad conection, wiring issue or a faulty ECU.
Is the engine 8 or 16V?
Is it a CF3 or CF4 ECU?

What "Fiat Daignostics" are you using?

The next steps are:
1/ Confirm the actual boost pressure and boost pressure reported by the ECU using a pressure gauge connected to the inlet system downstream of the turbocharger

2/ Record the inlet pressure, boost demand, MAF etc while forcing the fault. Multiecuscan will allow you to do that.

Robert G8RPI.

 

[Ralf S.]

I had a similar problem ages ago and more recently.

The more recently, I changed the MAP sensor for an original Bosch one and the problem (management light) disappeared immediately. I don't know what will happen when I drive it - the car is currently in bits while I replace the flywheel.. but it looks good that the EML went out immediately with the new MAP fitted.

Previous time was more tricksy. I had various problems with the EML coming on and off.

Back then I swapped the MAP sensor (unbranded one, but it was new...) The old one was full of oil where the previous owner had over-filled the engine, so it was getting blown into the inlet manifold. At the same time, I also replaced the little boost valve in front of the airbox... but with hindsight, I don't think that was necessary.

The main issue was (I think) the EGR valve. I removed that to clean it out and it was very sticky/stiff and full of soot and oil, from the oil being over-filled. Once I cleaned it up and made sure it was opening okay, I blanked it off on both ends.

If you have oil collecting in the inlet manifold you could have the same problem. The JTD can collect oil there, and it doesn't get sucked into the cylinders quickly enough. Instead it can pollute the MAP and find its way into the EGR.

As a free fix (just take things off and clean them out) I'd try the EGR... but also give your MAP sensor a clean out/fit a new one if you already have one.

Then run your oil level at 75% full.. to stop oil getting pumped into the inlet manifold. The level sensor will tell you if the oil level is getting low, so no reason to fill it to the MAX.


Ralf S.

 

[zugreveles]

Does the MP sensor give sensible readings?
What does the air temperature read?


The ECU cutting boost does sound like a pressure sensor issue.

It's not just the sensor that can cause a "MAP failure" It could be a bad conection, wiring issue or a faulty ECU.
Is the engine 8 or 16V?
Is it a CF3 or CF4 ECU?

What "Fiat Daignostics" are you using?

The next steps are:
1/ Confirm the actual boost pressure and boost pressure reported by the ECU using a pressure gauge connected to the inlet system downstream of the turbocharger

2/ Record the inlet pressure, boost demand, MAF etc while forcing the fault. Multiecuscan will allow you to do that.

Robert G8RPI.

It is 8v, I dont know which ecu or diagnostics. My mechanic also mentioned that maybe the problem is bad wiring or turbo sensor(i think he says), but we will consider this in the next 2 weeks.

 

[zugreveles]

I had a similar problem ages ago and more recently.

The more recently, I changed the MAP sensor for an original Bosch one and the problem (management light) disappeared immediately. I don't know what will happen when I drive it - the car is currently in bits while I replace the flywheel.. but it looks good that the EML went out immediately with the new MAP fitted.

Previous time was more tricksy. I had various problems with the EML coming on and off.

Back then I swapped the MAP sensor (unbranded one, but it was new...) The old one was full of oil where the previous owner had over-filled the engine, so it was getting blown into the inlet manifold. At the same time, I also replaced the little boost valve in front of the airbox... but with hindsight, I don't think that was necessary.

The main issue was (I think) the EGR valve. I removed that to clean it out and it was very sticky/stiff and full of soot and oil, from the oil being over-filled. Once I cleaned it up and made sure it was opening okay, I blanked it off on both ends.

If you have oil collecting in the inlet manifold you could have the same problem. The JTD can collect oil there, and it doesn't get sucked into the cylinders quickly enough. Instead it can pollute the MAP and find its way into the EGR.

As a free fix (just take things off and clean them out) I'd try the EGR... but also give your MAP sensor a clean out/fit a new one if you already have one.

Then run your oil level at 75% full.. to stop oil getting pumped into the inlet manifold. The level sensor will tell you if the oil level is getting low, so no reason to fill it to the MAX.


Ralf S.

When the car gets map sensor error on diagnostics, the mechanic told me that he puts the new one immediately (i dont know, bosch or unbrended one, but new.) After that he tries the car and everything was the same, problem was still here, so he cleans the old-dirt map sensor and puts back in.

He thinks that the problem maybe is bad wiring or connection or some turbo sensor… we will consider that next time

About that EGR you mentioned, i dont think this is connected to my problem (turbo going off) Logicaly would be some pressure or boost sensor ( or bad connection/wirring) but i will try that EGR cleaning or blanking it off for sure. If my map sensor was oiled and dirty, EGR is also like that

Do you feel any difference in performance or consumption after EGR cleaning/blanking?

 

[g8rpi]

I think you need a better garage....
The comment "or some turbo sensor…" indicates a lack of knowedge, the MAP sensor IS the turbo sensor.
The mechanic needs to be taking measurements and doing proper diagnostics, not just responding to fault codes.

Robert G8RPI.