2014 Leon 2.0 Tdi 150 - Severe hesitation + stop/start error and starting in limp mode

[SeaTC0125]

I have 2014 Leon 2.0 Tdi 150 with 46000 miles and in recent months it started to show signs of minor hesitation when driving in 3rd or 4th gear in revs between 1500 to 2000.

The issue got progressively worse to the point where the car started to jerk and hesitate severely and I could only drive the car by either letting off the throttle or full throttle. The car displayed and engine warning light with the error code P0236 - Powertrain - Turbo Boost Sensor

At the same time the stop/start limp mode issue also happened - When car is started in the morning the coil light is flashing and displaying the message "Error with Stop/Start system" and the car is in limp mode. I could get the car out of limp mode by driving a few meters and restarting the car.

I had booked the car into the SEAT garage at this point. They indicated that the MAF sensor was the issue so they replaced it. The hesitation stopped completely for maybe 15 days, but then I noticed the hesitiation starting to creep in again. I immediately brought the car back to the garage, but they were unable replicate the hesitation and they didn't do anything.

As of today, the car has started to do the Start/Stop Limp mode and Engine light P0236 issue again. It appears that replacing the MAF sensor only temporarily fixed the issue. I am beginning to think that there is a mechanical issue that is slowly damaging the MAF sensor, as the sensor should clearly last more then a month.

Any help would be greatly appreciated. I searched though these forums but could not really find anything similar.

 

[Legojon]

"P0236 is an OBD-II generic code that is triggered when the Engine Control Module (ECM) detects the intake boost pressure sensor A input circuit range or performance is out of specifications when compared to the manifold pressure sensor (MAP) or the barometric pressure sensor (BARO) at idle and with the key on, engine off, before starting."

So maybe a faulty MAP sensor?

 

[KXL]

Out of curiosity, what diesel does it take? The Shell/Esso/BP kind or more supermarket kind?

 

[SeaTC0125]

Out of curiosity, what diesel does it take? The Shell/Esso/BP kind or more supermarket kind?

Most of the time I buy my diesal at a Maxol garage (I'm in Ireland) which would be the equivalent to Shell or Esso. I avoid cheaper Tesco diesal etc.

 

[SeaTC0125]

"P0236 is an OBD-II generic code that is triggered when the Engine Control Module (ECM) detects the intake boost pressure sensor A input circuit range or performance is out of specifications when compared to the manifold pressure sensor (MAP) or the barometric pressure sensor (BARO) at idle and with the key on, engine off, before starting."

So maybe a faulty MAP sensor?

That is a possibility. I wonder could a fault like a leak in seals near the turbo could cause the issue either.

 

[KXL]

Most of the time I buy my diesal at a Maxol garage (I'm in Ireland) which would be the equivalent to Shell or Esso. I avoid cheaper Tesco diesal etc.

I wonder if you put a tank full of Esso Supreme / Shell Vpower or even Maxol's finest diesel with the claimed superior cleaning properties, would the problem go away. Maybe worth a try.

 

[SeaTC0125]

I wonder if you put a tank full of Esso Supreme / Shell Vpower or even Maxol's finest diesel with the claimed superior cleaning properties, would the problem go away. Maybe worth a try.

I would but they don't offer premium fuels in Ireland..haha.

 

[Legojon]

That is a possibility. I wonder could a fault like a leak in seals near the turbo could cause the issue either.

Are you losing any oil?

 

[SeaTC0125]

Are you losing any oil?

I had a look around the engine for any visible oil leaks and seems clear. Car had oil changed about two months ago and the oil level hasn't dropped.

 

[Legojon]

If you have one of the cheapo obd wifi connectors, you can use an app like torque to log maf / map values.
http://www.cpgnation.com/forum/threads/more-random-tech-information-map-sensors.24999/

 

[SeaTC0125]

If you have one of the cheapo obd wifi connectors, you can use an app like torque to log maf / map values.
http://www.cpgnation.com/forum/threads/more-random-tech-information-map-sensors.24999/

Yep I have one of those and also have the paid version of Torque Pro. I'll try set it up to log the values when I'm driving home from work later.

 

[KXL]

I would but they don't offer premium fuels in Ireland..haha.

Seriously? So all performance cars (and supercars) have to make do with standard 95 RON (or is it even lower?) and regular diesel?

Use Redex Diesel treatment (do you have those?)

 

[SeaTC0125]

Seriously? So all performance cars (and supercars) have to make do with standard 95 RON (or is it even lower?) and regular diesel?

Use Redex Diesel treatment (do you have those?)

Yep! There a few garages that stock premium fuels I believe but I've never seen them. It's one of the reasons why nobody has powerful cars in Ireland, between that and ridiculous tax rates and insurance.

Also I believe I can buy Redex online. Might pick up some.