I will start at the beginning, so information can be relayed in full and in correct order.
Daughter bought a 2007 D40 that had done a lot of work, but had just had the timing chains done, and had a box full of most of the running gear parts that were going to be needed for a roadworthy. It had also had a dpf delete done.
When she got it, turbo would regularly boost over the 25psi alarm point on the aftermarket gauge. Obd reader and torque app have since proved the accuracy of the aftermarket gauge. She just modified her driving so as to not overboost.
Coming off shift late one night, the Nav had zero boost. She limped home. I started fiddling around checking the usual problems; replaced the boost solenoid, vacuum hoses. Initially had no effect, then suddenly had some boost back. A bit of a test drive and it looked like it was getting up to 19psi boost.
Daughter started driving it again, but reported a bit more sluggish than it was before ... turns out that most of the time, 10-15 psi of boost was all it would get. After a few weeks she'd had enough and said she wasn't driving it again until it was fixed. So I moved on and cleaned the MAF sensor.
After the first real drive I'd done in it where it had momentarily seen 20-22psi boost, once coming out of a roundabout, and another just cruising at 80kmh, I popped off the front pipe from the turbo and checked the shaft play, having heard a momentary high pitched squeal on 2 occasions when revving it in in Park (daughter later mentioned that it had started doing this in the last couple of weeks) It was definitely at the point where the vanes had just started scraping the housing, with a faint metallic sheen evident on a finger wiping the housing between the vanes. It was assumed that a bearing in the process of failing was restricting spool up speed except where all the stars aligned, giving momentary "normal" boost. In hindsight, this may possibly been caused by the overboost condition that the turbo could be put in on occasion.
Anyway ... new turbo, intercooler clean, check oil feed on reassembly, prime turbo with oil both before installation and before starting by turning the engine over with injector plugs disconnected, and we now have 5-10psi max boost. Even driving down the road not just in park and stationary.
Fitted the EGR blocking plate, although I assume it would have been done electronically at the time of the dpf delete? No change.
Bypassing the BCS and fitting vacuum hose directly to the actuator produced a little more boost, but still maxing under 15psi (stationay in park), and now that same high pitched squeal as before replacing the turbo. Unfortunately no one else around to work the accelerator for me to see where the noise was coming from. Having belatedly found a post about the small vacuum line connection point near the oil filter being a problem blockage point, I pulled that out and ensured it was clear and free flowing. Couldn't believe the pin prick hole that was expected to allow vacuum through, so I may have slightly enlarged it while ensuring it was clean and unblocked. While on that side of the car, I cleaned the earth point behind the ecu, despite it looking very clean. Started her up, and zero change.
Not having much hair left at this point, I threw a hail mary and put the old BCS back in noticed a difference in boost gauge movement and went for a short test drive, up to about 60km/h, and was able to get around 19psi of boost without too much drama or alarming the neighbours with a speeding bonnetless 4wd whizzing by ...
Feeling pretty drained by the whole experience ... and believe there have been a number of parallel issues, including dud new BCS, borderline turbo bearing, perished hoses and I don't know what was causing the initial overboost-ability ...
Not sure I am done yet ... have to throw the bonnet back on and go for a longer test drive to see exactly how the boost behaves. Still don't know what the high pitched squeal was, though it did sound a lot like belt slippage to me; despite only appearing when bypassing the bcs. I guess it could be a boost leak somewhere in the intake path ... would probably have to be the intercooler as all the hoses, clamps, pipes, gaskets are secure. There was a small amount of oil seepage at one corner of the intercooler, but this was not as bad as from several of the intake pipe connections.
Any observations, opinions, advice in light of the full story and timeline, would be much appreciated.
Daughter bought a 2007 D40 that had done a lot of work, but had just had the timing chains done, and had a box full of most of the running gear parts that were going to be needed for a roadworthy. It had also had a dpf delete done.
When she got it, turbo would regularly boost over the 25psi alarm point on the aftermarket gauge. Obd reader and torque app have since proved the accuracy of the aftermarket gauge. She just modified her driving so as to not overboost.
Coming off shift late one night, the Nav had zero boost. She limped home. I started fiddling around checking the usual problems; replaced the boost solenoid, vacuum hoses. Initially had no effect, then suddenly had some boost back. A bit of a test drive and it looked like it was getting up to 19psi boost.
Daughter started driving it again, but reported a bit more sluggish than it was before ... turns out that most of the time, 10-15 psi of boost was all it would get. After a few weeks she'd had enough and said she wasn't driving it again until it was fixed. So I moved on and cleaned the MAF sensor.
After the first real drive I'd done in it where it had momentarily seen 20-22psi boost, once coming out of a roundabout, and another just cruising at 80kmh, I popped off the front pipe from the turbo and checked the shaft play, having heard a momentary high pitched squeal on 2 occasions when revving it in in Park (daughter later mentioned that it had started doing this in the last couple of weeks) It was definitely at the point where the vanes had just started scraping the housing, with a faint metallic sheen evident on a finger wiping the housing between the vanes. It was assumed that a bearing in the process of failing was restricting spool up speed except where all the stars aligned, giving momentary "normal" boost. In hindsight, this may possibly been caused by the overboost condition that the turbo could be put in on occasion.
Anyway ... new turbo, intercooler clean, check oil feed on reassembly, prime turbo with oil both before installation and before starting by turning the engine over with injector plugs disconnected, and we now have 5-10psi max boost. Even driving down the road not just in park and stationary.
Fitted the EGR blocking plate, although I assume it would have been done electronically at the time of the dpf delete? No change.
Bypassing the BCS and fitting vacuum hose directly to the actuator produced a little more boost, but still maxing under 15psi (stationay in park), and now that same high pitched squeal as before replacing the turbo. Unfortunately no one else around to work the accelerator for me to see where the noise was coming from. Having belatedly found a post about the small vacuum line connection point near the oil filter being a problem blockage point, I pulled that out and ensured it was clear and free flowing. Couldn't believe the pin prick hole that was expected to allow vacuum through, so I may have slightly enlarged it while ensuring it was clean and unblocked. While on that side of the car, I cleaned the earth point behind the ecu, despite it looking very clean. Started her up, and zero change.
Not having much hair left at this point, I threw a hail mary and put the old BCS back in noticed a difference in boost gauge movement and went for a short test drive, up to about 60km/h, and was able to get around 19psi of boost without too much drama or alarming the neighbours with a speeding bonnetless 4wd whizzing by ...
Feeling pretty drained by the whole experience ... and believe there have been a number of parallel issues, including dud new BCS, borderline turbo bearing, perished hoses and I don't know what was causing the initial overboost-ability ...
Not sure I am done yet ... have to throw the bonnet back on and go for a longer test drive to see exactly how the boost behaves. Still don't know what the high pitched squeal was, though it did sound a lot like belt slippage to me; despite only appearing when bypassing the bcs. I guess it could be a boost leak somewhere in the intake path ... would probably have to be the intercooler as all the hoses, clamps, pipes, gaskets are secure. There was a small amount of oil seepage at one corner of the intercooler, but this was not as bad as from several of the intake pipe connections.
Any observations, opinions, advice in light of the full story and timeline, would be much appreciated.
