Exmoor Beast Posted June 30, 2015 Share Posted June 30, 2015 So just over a week into my P38 dse ownership and theres a sudden lack of input from the turbo. It has been chipped and did go like a scoulded cat from 2000rpm. Now theres no boost from the turbo at all, 1 in 4 hills are now 1st gear instead of 2nd/3rd. It still revs to the red line ok, no smoke, everything seems fine other than the lack of get-up-and-go. I have taken the hose off from the plastic air inlet to turbo and looked down it at 3000rpm and it didn't seem to be delaminating which was my first thought. Its not easy to see far down it though so it maybe collapsing lower down. If nobody has any better ideas I'll take it right off and have a proper look. I did let it get a little low on fuel, light had just come on and I was going up a 1 in 3 hill when it lost power so maybe its picked up some carp and blocked the fuel filter? Is there anything else obvious anyone can think of? Cheers Will :-) Quote Link to comment Share on other sites More sharing options...
Simon_CSK Posted June 30, 2015 Share Posted June 30, 2015 Will you should have bought a proper Range Rover. Then it would be overheating Quote Link to comment Share on other sites More sharing options...
Boydie Posted June 30, 2015 Share Posted June 30, 2015 A new fuel filter is the first replacement, secondly there is a micro-fine mesh inside the banjo connection on the FIP, check that this isn't blocked and if it is clear it with compressed air, turn the engine over with the banjo disconnected to ensure a flow of clean fuel before re-fitting it. I'm also assuming that you have checked and cleaned the sedimenter filter, this could be full of debris and or water. If you ran the engine and there was next to zero fuel you may have damaged the mechanical fuel lift pump, so check that that is pumping when you fit the new fuel filter. Quote Link to comment Share on other sites More sharing options...
elbekko Posted July 1, 2015 Share Posted July 1, 2015 Check the line to the turbo pressure sensor, it's a little black box on the RH shock turret IIRC. Quote Link to comment Share on other sites More sharing options...
steve b Posted July 1, 2015 Share Posted July 1, 2015 And the sensor , they sometimes get clogged with oil that gets up the pipe to it , a squirt of brake cleaner should clear it . cheers Steveb Quote Link to comment Share on other sites More sharing options...
pete3000 Posted July 1, 2015 Share Posted July 1, 2015 can you take the hose off from the air cleaner to the inlet of the turbo and see if the turbo is spinning up? not sure on the p38a. Could be a wastegate is stuck open via a seized pushrod or linkage if it's just packed in with no warning. Quote Link to comment Share on other sites More sharing options...
Arjan Posted July 1, 2015 Share Posted July 1, 2015 Don't we love these P38's..... Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted July 1, 2015 Share Posted July 1, 2015 Don't know if the P38 has a VNT but the TD4 Freebie (another BMW lump) the turbo actuator is vacuum-controlled and the small vacuum line can easily perish/split/fall off and result in zero boosts. Quote Link to comment Share on other sites More sharing options...
Exmoor Beast Posted July 1, 2015 Author Share Posted July 1, 2015 Cheers all, thats a bit more to go on :-) I'll report back after further investigation...... Will :-) Quote Link to comment Share on other sites More sharing options...
P38 Paul Posted July 1, 2015 Share Posted July 1, 2015 Hello Will , I had some thing similar happen on my motor so as a simple test , unplug the mass air flow meter " MAF " & then go for a test drive to see if you have regained some of the power , if so it is the " MAF " at fault , you can drive it around like this but it will have reduced power & eventually you will need to fit another MAF , it worked for me , Kind regards , Paul . Quote Link to comment Share on other sites More sharing options...
Exmoor Beast Posted July 2, 2015 Author Share Posted July 2, 2015 It doesn't appear to have a MAF sensor Paul :-/ Everything else mentioned seems to be a blighter to get at, couldn't see anything like a vacuum pipe anywhere near the turbo but its a bit of a black hole up under there! The search goes on :-( Will Quote Link to comment Share on other sites More sharing options...
David Sparkes Posted July 2, 2015 Share Posted July 2, 2015 The turbo is not a VNT model, so there is no vacuum pipe relating to the turbo. The bypass valve (wastegate if you like) responds to positive pressure generated by the turbo-charger. There is a ~6mm diameter flexible pipe feeding the output pressure to the bypass valve actuator. From above, this tends to be hidden by the heatshield, it only becomes 'easy' to get at once the exhaust manifold is removed. You might be able to access it from below, but it is high in the engine bay. There are some good pictures in Section 12 of the Workshop manual (Engine-BMW diesel). Only the later DSE's had mass airflow meters fitted (2000MY on, IIRC). As you don't have a MAF, I suspect you don't have EGR either. If you want to check boost pressures it is much easier to interrupt the pipe (rubber, but with a braided cloth cover) between the inlet manifold and the pressure sensor. As the pipe diameter is small, the typical tee piece found in windscreen washer piping is capable of withstanding the pressures involved, as is the rubber screenwash piping fitted on cars from colder climates. I found Volvos a good source. You don't need hose clips, just cut off and discard the pre-stretched last 1/2" of pipe and the resultant push fit will be fine. The cheapest gauges are non-automotive, 0-30 psi as fitted to the outlet ports of gas welding bottles, although you will need to source or create your own pipe to gauge adaptor. These are fine for diagnostic work, I'm not suggesting using them for a permanent installation. You mentioned 'chipped'. Is this via a modification to the processor in the engine ECU, or via an external black box? If an external box I suggest removing it, but as we don't know anything about it I can't say whether any wiring connections should be left hanging, or joined together in some way. The 'gotcha' I recall being warned about was if the boost pressure went too high for the standard pressure sensor the engine ECU would go into limp home mode, although I also understood that engine switch off, then restart, was enough to reset the ECU. You mention 'no smoke'. To the best of my recollection, my experience was that if the boost pressure failed 'mechanically', such as the intake pipe coming off the inlet manifold, the result was copious black smoke. HTH Quote Link to comment Share on other sites More sharing options...
steve b Posted July 2, 2015 Share Posted July 2, 2015 The boost pressure sensor is mounted on the side of the fuel filter Will, on nearside inner wing . If it's not working for whatever reason the EDC goes to a default setting which will allow continued use but it will feel gutless , a struggle to get to 70mph. cheers Steveb Quote Link to comment Share on other sites More sharing options...
Exmoor Beast Posted July 2, 2015 Author Share Posted July 2, 2015 Haha, the braiding on the pipe to the sensor on the fuel filter is worn through and it looks like it might well be holed! I'll see what I can blag to replace it tomorrow. Progress I hope.... Will :-) Quote Link to comment Share on other sites More sharing options...
P38 Paul Posted July 2, 2015 Share Posted July 2, 2015 Hello Will , What year is your car ? I thought all diesels had a MAF , Its the unit just after the air filter with the wire coming out . regards , Paul . Quote Link to comment Share on other sites More sharing options...
Exmoor Beast Posted July 5, 2015 Author Share Posted July 5, 2015 M plate Paul. Replaced the suspect pipe but no improvement. Hooked it up to a mates laptop but it couldn't speak to it to see if theres a fault logged :-/ Ho hum.. Will Quote Link to comment Share on other sites More sharing options...
Exmoor Beast Posted July 15, 2015 Author Share Posted July 15, 2015 So, the saga continues. I have replaced the suspect pipe and we have hooked it up to clear the fault codes. 3 logged: 146 brake switch 25 glow control 135 boost control Still no improvement, any suggestions? Will :-) Quote Link to comment Share on other sites More sharing options...
David Sparkes Posted July 15, 2015 Share Posted July 15, 2015 You didn't answer my question about the 'chipping'. Is this via a modification to the processor in the engine ECU, or via an external black box? If an external box I suggest removing it, but as we don't know anything about it I can't say whether any wiring connections should be left hanging, or joined together in some way. Do you have any more details about who did the work, have any informative labels been left around? Regards. Quote Link to comment Share on other sites More sharing options...
elbekko Posted July 15, 2015 Share Posted July 15, 2015 Boost control would lead me to the boost sensor, as I pointed out earlier. Quote Link to comment Share on other sites More sharing options...
Exmoor Beast Posted July 15, 2015 Author Share Posted July 15, 2015 I wasn't sure if 'boost control' was the sensor on the fuel filter or something else. I'll replace the sensor next then. would you expect that to clear the fault or is it another 40mile trip to hook it up again? If it is then I'm buying a doofa to do it myself! 'Chipping' is an external black box that lives on the n/s inner wing, no makers mark :-/ it looks a bit bodged in to be honest but the RR certainly went well before this caper started :-) Cheers chaps Will :-) Quote Link to comment Share on other sites More sharing options...
elbekko Posted July 15, 2015 Share Posted July 15, 2015 RAVE says: Boost Pressure SensorThe boost pressure sensor signal is used inconjunction with the air temperature signal tocalculate volume air flow into the engine. The sensoris located on the rear bulkhead, with the pressuretap just after the charge air cooler. If the sensor fails,a substitute value of 490 hPa is used by the ECM(Z132), producing a reduction in power due to a fuelquantity limiting to 21mg/stroke. Not sure if the fault will clear itself. This is a regular OBD fault though, so a £15 eBay ELM327 adapter and your smartphone can clear it (and it'll come in handy later as well). Quote Link to comment Share on other sites More sharing options...
David Sparkes Posted July 15, 2015 Share Posted July 15, 2015 ... 'Chipping' is an external black box that lives on the n/s inner wing, no makers mark :-/ it looks a bit bodged in to be honest but the RR certainly went well before this caper started :-) Can you trace out the wiring from the black box? It's possible that it merely modifies the output from the boost sensor, so reporting a lower pressure to the engine ECU, which allows more fuelling to the engine, which in turn increases the volume of exhaust gas through the turbo, effectively raising the boost pressure. I can see the attractiveness of buying a relatively cheap device to read the codes and reset them. You can read Flash Codes without anything more sophisticated than the relevant knowledge and a piece of wire (good eyesight and being able to count flashes being taken for granted), but error codes cannot be reset. My experience is now some years out of date, it precedes the Nanocom family of products, for instance, but the Rovacom Lite I used gave details of the actual values 'seen' by the ECU. Thus both Atmospheric pressure and Boost pressure were displayed in Kpa. You reported several error codes, 146 brake switch, 25 glow control, 135 boost control, which I assumed had been cleared. If this is so then it will be useful to see which has reoccurred, as the system in the car doesn't record how old the codes are. Code output does not relate to any sort of time clock, either as to a specific date, or to 'XXX hours ago'. If the codes were cleared, but the error light came on when the engine was re-started, then the codes should have been read again, immediately, so the permanent error code was identified. Some error codes can be intermittent, and it will take several instances before a dashboard warning is illuminated. I confess the numbers + text you show don't relate to anything I have in the Rovacomm data, either in the Help screens or the Flash codes. There is no Flash Code 25, 135, or 146, nor even 35 or 46. (In the Flash Code list Brake Pedal is 37. Glow Plug control is 49. Manifold pressure sensor codes are 41 to 44, inclusive). This leads me to suspect the ones you have are from another standard used by that particular Code Reader, and you could do with a more detailed explanation as to what 'your' codes actually mean. This might be in the handbook, or online help, of the Code Reader used, but I wouldn't hold my breath. If you are considering a propriety Code Reader I suggest you look for a support forum, as this might be the only form of support available to you. I don't know if you have downloaded RAVE, but this is from the section on European On Board Diagnostics (E-OBD). Diagnostic Trouble Codes (DTCs) The Diagnostic Trouble Codes or “P-codes”, are distinguished between 'Mandatory' and 'Voluntary' codes. The Society of Automotive Engineers (SAE) defines mandatory (core) codes. The SAE codes can be identified by a '0' before the 3-digit numeric part of the code (e.g. P-0234). Voluntary codes are manufacturer specific codes (e.g. Land Rover) and are identified by a '1' before the three digit code (e.g. P-1234). The mandatory P-codes are consistent for all vehicle types worldwide, irrespective of manufacturer or market i.e. the occurrence of a particular mandatory P-code will indicate the same type of component error as defined by the SAE description irrespective of vehicle type or manufacturer. A comprehensive list of P-codes is included in tabular form later in this document. The list runs to several pages, as it includes all the SAE standards, even the ones that aren't (weren't) used by Land Rover. Trying to relate your '135 boost control' doesn't work, as P0135 relates to an O2 sensor, used with catalytic converters on petrol engines, and there is no code P1135 shown, the P1xxx codes before and after P1135 relate to monitoring the O2 sensors. Regards. Quote Link to comment Share on other sites More sharing options...
Exmoor Beast Posted July 16, 2015 Author Share Posted July 16, 2015 Wow thanks for your efforts chaps :-) the new sensor hasn't arrived in the post today :-( so another day with no progress. The connection for my phone sounds like a very good move. I have got an lead and EAS software for the laptop but haven't set it up yet, not sure if that will clear anything other than EAS faults. I'll give it a go tonight if the rain holds off :-) Cheers Will :-) Quote Link to comment Share on other sites More sharing options...
elbekko Posted July 16, 2015 Share Posted July 16, 2015 Nope, that'll only talk to the EAS. Quote Link to comment Share on other sites More sharing options...
Exmoor Beast Posted July 16, 2015 Author Share Posted July 16, 2015 Just discovered that at lunchtime, on the plus side the EAS is in fine health with no faults listed :-) Ordered a doofa for the phone as suggested :-) Will Quote Link to comment Share on other sites More sharing options...
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