1.6 tdci Underboost problem

[gronvall]

Hey Ford owners

I have a 2010 ford focus 1.6 tdci with 109hp.

 

The problem:

The car is very slow and it is very clear than it is lacking power. I have recorded some graphs while i were driving the car where the boost pressure is very low i have attached these.

 

What i have tried:

I have had the underboost problem for a while now and have tried nearly everything to fix it.

I have changed the Turbo, DPF, Actuator solonoid valve, Airfilter and Egr.

I have also blocked off the EGR,

I have checked the turbo actuator which pulls down when engine starts and releases when engine is stopped. The actuator moves freely.

I have tried to check the hoses freom the turbo through the intercooler and up till the engine intake and i can't find any cracks or oil build up there.

 

Do anybody have any idea what can be wrong? i have tried almost everything. if you need some extra data or graphs i will gladly do so.

 

[gronvall]

I forgot to say that the fault code is P0299 Turbo underboost

[Tekno]

few things to check

Map sensor/boost pressure sensor

cat could be blocked not allowing engine to breath properly so the turbo cant spool up to speed

boost leak any sign of leakage from intake system after the turbo or intercooler leak if fitted 

Mas air flow sensor could be at fault ie it thinks its getting x meters per second or air per second when its getting y meters per second throwing off the map senors as it should read x boost psi but its getting y boost psi.

All these little things could lead to no boost as the system shuts down to protect itself also is the turbo a new second or recon as we say in the trade just coz you replaced it dont mean its ok. is the actuator adjustable could have been set wrong so your loosing to much pressure and not getting the turbo up to speed to give you the boost.

lots to take in i know but its always hard to diagnose something like this remotely.

 

[gronvall]

I dont think it is the MAP, because i can feel the lack of power.

As far as i know the cat is also inside of the dpf and is therefore also new as i have changed the dpf

I have tried to check the entire intake system for leaks, but i have not found any leaks.

I am considering the MAF sensor and i have already ordered a new one but it will take some days before i get it

The turbo is a recon unit, so it could definently also be bad, and the actuator is adjustable but it is painted on the nut so i think it have been calibrated.

[Tekno]

When i say MAP im referring to the MAP/Boost sensor the not engine map in the ECU. (manifold absolute pressure = MAP) if it read higher or lower pressure than it should it shuts down the turbo system to prevent damage.

Boost leaks are a git to find some signs can be slight oiling around joins excess dirt build up along pipes. You can use a heavy smoke source to see if you getting a blow from the intake system, but it need to be heavy smoke other wise you won't see it there was some i saw a while ago with dye in as well so you could use a uv source, other tricks are using a mist spray (be careful flammable etc) around the pipes and joins to see if you have air coming out or air being drawn in the engine pitch will change for a second or two.

Side note check for weak jubiles or spring clips on the pipes they could be leaking under pressure.

Without knowing full vehicle details hope this helps.

 

 

[Tizer]

Do you know if your car is one of the later Euro5 ones?.

I had a MK 2.5 Euro5 one and although I did not have problems, I used to do a lot of monitoring for reference purposes.

My MAF values were always just below 6 g/s at Idle and I notice that your ones are a lot higher. If you have one of the earlier engines then that may be why, or maybe my readings were wrong. Another reason maybe because you have blanked off your EGR, so extra air need to be taken in the compensate.

My MAP readings could get as high as 200-250 kPa under extreme load, but only for a short time. I believe that somewhere near 250 is the maximum for these engines.

Your problems are likely to be one of the ones that @Tenko has pointed out, but for completeness have you had a look at the DPF Pressure values and that the Throttle Valve is behaving itself. I don't think that they are the source of the problem, but they may provide some further clues.