1.6 tdci boost pressure drop

[bigmick1981]

Hello all got a grand cmax 1.6tdci 115 

But not getting much luck on body specific forum so thought you hip happening folks might be able to throw some light on my problem as I'm sure we share engines 

 

 

Any how .........

 

 

 

Noticed sometimes when driving along the car feels sluggish , so plugged in a obd scanner and when driving no issues it will boost to a steady 22 psi . When the car looses some performance it will only boost to 18 psi , it's usually happening after a gear change but has happened a couple of times at early stage of acceleration . Now for the strange part if it drops to giving me a solid 18 psi it doesn't mater if I back of the throttle and foot down again or push through it will only give a steady 18 psi but if i quickly down and up with the clutch it will give me back the boost to 22 psi . 

 

Any ideas folks ? 

[simcor]

Are there any error codes present? Have you got a tool to read any DTC's?

The boost will be variable as it has a VNT turbo, the vanes move position to make the turbo spool more or less as required, so I would expect the boost pressure to vary to a degree depending on how much boost is required for the road speed and engine load.

[madmole]

My 1.6tdci boosts to 2 bar (28 psi) flat out at max acceleration. Normal hard accel is 1.8 bar, idle around -0.6bar

[bigmick1981]

Yeah I've forscan mobile and have a clean sheet on fault codes the computers are all happy. Haven't noticed it doing it more than once on a trip. Wouldn't have thought it being a clutch switch but just guessing at that 

[bigmick1981]

Other than this hiccup car runs brilliant no smoke at all no noises excellent mpg . Infact tailpipe is clean to the touch the first diesel I have had without soot built up in It . Dpf readings all good max differential is at around 18kpa which I'm sure I read it quite good. Maybe egr leaking boost when going on boost but again wouldn't have thought clutch operation would have any effect on egr opening and closing 

[bigmick1981]

Should have said diesel filter , air filter , oil and filter done this was done mid service interval as I don't believe 10k servicing is good enough so opting for 5k instead ....... overkill ? Maybe but for under 90 quid it's not breaking the bank and can only be good for car (using correct oil etc) 

[bigmick1981]

Slightly off topic but Haven't checked injector seals yet are these still prone to go on the newer/last gen 1.6tdci ?or did ford get their act together and fit better seals mid build of this engines run 

[simcor]

18kpa is a lot of pressure differential on the DPF as far as I can tell, mine barely gets to 1kpa even under hard acceleration.

 

[bigmick1981]

From what I have read on peugoet and mazda forums up to 30kpa is normal ...... but I stand to be corrected ?