BramPeeters
New member
Hi,
I am looking into an issue for a week now where apparently too much exhaust gasses are blown into the intake as soon as the egr valve opens a little (problem started after replacing the old stuck egr with a new one), which leads to stuttering when driving (but no fault codes).
My engine is a DIESEL TURBO PUMA C 96 EURO5 130HP (fitted in a 2014 boxer)
So far I have been working under the assumption that this is caused by the fact that there is too much back pressure in the exhaust manifold for some reason, so that when the egr valve opens it all just blows into the intake starving the engine for oxygen (I know this happens because of maf scope loggings where you see that the air intake drops like a stone as soon as he opens the egr vale, and also if I hold a piece of paper in front of the intake, it gets blown outwards every time he tries to open the egr valve, which happens every about 640 ms ). [ sidenotes: the new egr valve has been "learned", and i visually checked after taking it out again that the valve moves to the 4 positions during an actuator test in diagbox and reports its position; in idle it opens to about 20 pct which is the target set by the ECU, before being shut close again ]
When I take out my egr, put blanking plates in its place, and add a nipple to do pressure readings at the plate connected to the exhaust manifold (via the water cooler), I get 0.3bar at idle and up to 2.5 bar at 3000 rpm.
Thinking these values are too high I disconnected dpf and catalysator and i still have 0.3bar at idle which was unexpected because normally one of these is the one that gets clogged up (there is not much else anymore left now, it is just exhaust manifold->turbo->outside world).
So I am questioning my 'backpressure is too high' reasoning now.
I have very conflicting info on whether or not 0.3 bar backpressure in the exhaust manifold is normal or not (way too high <-> ok values for these engines). ( My mechanic thinks the value is too high but he is not sure now since I already disconnected all the filters. )
Is there anyone who has more information about what a normal back pressure is suppose to be in the exhaust manifold of these kind of engines ?
I am looking into an issue for a week now where apparently too much exhaust gasses are blown into the intake as soon as the egr valve opens a little (problem started after replacing the old stuck egr with a new one), which leads to stuttering when driving (but no fault codes).
My engine is a DIESEL TURBO PUMA C 96 EURO5 130HP (fitted in a 2014 boxer)
So far I have been working under the assumption that this is caused by the fact that there is too much back pressure in the exhaust manifold for some reason, so that when the egr valve opens it all just blows into the intake starving the engine for oxygen (I know this happens because of maf scope loggings where you see that the air intake drops like a stone as soon as he opens the egr vale, and also if I hold a piece of paper in front of the intake, it gets blown outwards every time he tries to open the egr valve, which happens every about 640 ms ). [ sidenotes: the new egr valve has been "learned", and i visually checked after taking it out again that the valve moves to the 4 positions during an actuator test in diagbox and reports its position; in idle it opens to about 20 pct which is the target set by the ECU, before being shut close again ]
When I take out my egr, put blanking plates in its place, and add a nipple to do pressure readings at the plate connected to the exhaust manifold (via the water cooler), I get 0.3bar at idle and up to 2.5 bar at 3000 rpm.
Thinking these values are too high I disconnected dpf and catalysator and i still have 0.3bar at idle which was unexpected because normally one of these is the one that gets clogged up (there is not much else anymore left now, it is just exhaust manifold->turbo->outside world).
So I am questioning my 'backpressure is too high' reasoning now.
I have very conflicting info on whether or not 0.3 bar backpressure in the exhaust manifold is normal or not (way too high <-> ok values for these engines). ( My mechanic thinks the value is too high but he is not sure now since I already disconnected all the filters. )
Is there anyone who has more information about what a normal back pressure is suppose to be in the exhaust manifold of these kind of engines ?
