tjolliffe Posted August 29, 2013 Share Posted August 29, 2013 Hi all, Got the classic Td5 surging under load problem on my disco 2. I'm struggling to work out what is causing it though. It does it from cold starting in the morning and then will continue to do it even when the engine is warm. However, if you turn it off and let it cool down for half an hour or so the problem goes away and it won't do it again even when the engine is back up to temp. I have tried wd40 on the wastegate and actuator but it doesn't seem to have had much of an impact. It moves ok. Anyone got any ideas? Should I be looking for a sensor issue? I have a diagnostics kit I can plug in, just not sure where I should be looking.... Thanks Tom Quote Link to comment Share on other sites More sharing options...
Tanuki Posted August 29, 2013 Share Posted August 29, 2013 When was the fuel-filter last changed? You could also have a tiny air-leak in one of the diesel lines and it's sucking in air. Final thing - depending on the age and mileage of the vehicle - check for the old "oil in the injector-harness" issue. After that, get the ECU's fault-codes read before you start spending money on randomly replacing any sensors. Quote Link to comment Share on other sites More sharing options...
spcollins Posted August 29, 2013 Share Posted August 29, 2013 I have exactly the same issue. The injector loom was just changed and it had a full service (including all filters) but the problem remains. The fuel regulator was changed too at the same time. Still no better. Also, on startup, it can be "lumpy" for about 5 seconds. I would also appreciate suggestions to help solve this problem. Quote Link to comment Share on other sites More sharing options...
spcollins Posted August 29, 2013 Share Posted August 29, 2013 Sorry - its a 2004 TD5 Disco Auto. Quote Link to comment Share on other sites More sharing options...
Roverdrive Posted August 29, 2013 Share Posted August 29, 2013 I had a lesser problem on my TD5 auto Disco, as it only manifested itself at full power when overtaking (!) gearbox would change up and down, and engine revs surged. Turned out to be the MAF. Quote Link to comment Share on other sites More sharing options...
Anderzander Posted August 29, 2013 Share Posted August 29, 2013 I was going to suggest unplugging the MAF to see if it made a difference. It's a free easy test to start things off ? Quote Link to comment Share on other sites More sharing options...
reb78 Posted August 29, 2013 Share Posted August 29, 2013 Also, on startup, it can be "lumpy" for about 5 seconds. I would also appreciate suggestions to help solve this problem. Common consensus with the lumpy startup is that this is normal. Most people suggest that 5 cylinders and 4 glowplugs probably cause it. Quote Link to comment Share on other sites More sharing options...
spcollins Posted August 29, 2013 Share Posted August 29, 2013 I had a lesser problem on my TD5 auto Disco, as it only manifested itself at full power when overtaking (!) gearbox would change up and down, and engine revs surged.Turned out to be the MAF. Well I have changed almost everything else so that would make sense. Thanks for the suggestion. Quote Link to comment Share on other sites More sharing options...
spcollins Posted August 29, 2013 Share Posted August 29, 2013 I was going to suggest unplugging the MAF to see if it made a difference. It's a free easy test to start things off ? Will do - thank you! Quote Link to comment Share on other sites More sharing options...
Tanuki Posted August 29, 2013 Share Posted August 29, 2013 Common consensus with the lumpy startup is that this is normal. Most people suggest that 5 cylinders and 4 glowplugs probably cause it. At this time of year (at least here in the UK) I doubt a TD5 is going to bother energising the glowplugs even when starting from cold. Provided it's not several degrees below freezing, my TD5 fires up within a couple of revolutions of cranking, and idles smoothly thereafter. If yours doesn't then there's a problem. [remember that the "glowplug" light on a TD5 doesn't actually indicate the glowplugs are active! When it goes out it just means the ECU's completed its self-test and we're ready to spool-up. The glowplugs operate independently of the light - in really cold weather they may be kept on and/or cycled on and off (for emissions-reduction purposes) for some considerable time after you've successfully started the engine] Quote Link to comment Share on other sites More sharing options...
tjolliffe Posted August 29, 2013 Author Share Posted August 29, 2013 So general consensus is its probably the MAF. To be honest at £30 for a replacement I'll probably just chuck a new one on it. I have tried to clean the one that is on there but I'm all to aware this often doesn't fix the route problem. I will update once I have changed the MAF... Quote Link to comment Share on other sites More sharing options...
Tanuki Posted August 29, 2013 Share Posted August 29, 2013 So general consensus is its probably the MAF. To be honest at £30 for a replacement I'll probably just chuck a new one on it. I have tried to clean the one that is on there but I'm all to aware this often doesn't fix the route problem. I will update once I have changed the MAF... Be aware that cheap-off-Ebay MAFs have a really bad reputation! If it's not guaranteed to be made by Siemens or VDO - run away! Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted August 29, 2013 Share Posted August 29, 2013 I'd go back to the wastegate,disconnect the MAF for now to see if its causing the problem.If there is no change - which is what I would expect,remove the boost capsule from the wastegate arm.Then hold the arm twixt finger and thumb,move it back and forth rapidly over its full arc of movement.If it does this with very little effort and does not stick AT ALL then fine - if it does stick just once then its too much.WD40 around where the shaft enters the turbo housing and gentle tapping with a light hammer around the area where the shaft goes into the casting.Do this for up to 5 mins whilst moving the arm back and forth to break up / release the arm fully.This gives full control of boost which is needed at as little as 1800rpm. Quote Link to comment Share on other sites More sharing options...
tjolliffe Posted August 29, 2013 Author Share Posted August 29, 2013 Thanks AllyV8 I will also try that at the weekend! Fingers crossed that sorts it. I have WD40'd it but to be fair not broken it down that much to do so.. Quote Link to comment Share on other sites More sharing options...
tjolliffe Posted August 31, 2013 Author Share Posted August 31, 2013 Ok, so I did what AllyV8 suggested. I removed the heat guard, disconected the wastegate arm from the actuator then spent a good 20mins wiggling it and coating in copeus amounts of WD40 and tapping the around the wastegate with a wooden mallet. Initial indications are that this has resolved the problem. Further updates if the problem returns.... Quote Link to comment Share on other sites More sharing options...
Anderzander Posted August 31, 2013 Share Posted August 31, 2013 Excellent ! Quote Link to comment Share on other sites More sharing options...
tjolliffe Posted September 19, 2013 Author Share Posted September 19, 2013 Update. This has not fixed the problem. I am now convinced it is a sensor issue. If you stop the engine and turn ignition off for appox 30 seconds when you re-start the problem will be gone. So, I have plugged in my diagnostics kit. The manifold pressure seems to be all over the place when it is doing it. Ie. reading at about 80kpa on idle with an ambient pressure of 100kpa ish. This would lead me to believe the MAP sensor is playing up. Would others agree? Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted September 19, 2013 Share Posted September 19, 2013 From memory the MAP sensor has a 5v feed to it,this often gets shorted out around the engine giving allsorts of problems,so I'd check the wiring before blaming the sensor,I cant remember ever replacing one of those on a TD5.... Quote Link to comment Share on other sites More sharing options...
bus man Posted October 1, 2013 Share Posted October 1, 2013 Hi all, Got the classic Td5 surging under load problem on my disco 2. I'm struggling to work out what is causing it though. It does it from cold starting in the morning and then will continue to do it even when the engine is warm. However, if you turn it off and let it cool down for half an hour or so the problem goes away and it won't do it again even when the engine is back up to temp. I have tried wd40 on the wastegate and actuator but it doesn't seem to have had much of an impact. It moves ok. Anyone got any ideas? Should I be looking for a sensor issue? I have a diagnostics kit I can plug in, just not sure where I should be looking.... Thanks Tom Hi all, Got the classic Td5 surging under load problem on my disco 2. I'm struggling to work out what is causing it though. It does it from cold starting in the morning and then will continue to do it even when the engine is warm. However, if you turn it off and let it cool down for half an hour or so the problem goes away and it won't do it again even when the engine is back up to temp. I have tried wd40 on the wastegate and actuator but it doesn't seem to have had much of an impact. It moves ok. Anyone got any ideas? Should I be looking for a sensor issue? I have a diagnostics kit I can plug in, just not sure where I should be looking.... Thanks Tom hi I have had the same problem , had it plugged in and tested . no faults came up , changed the filter , still the same , it turned out to be a little hole in the little rubber pipe behind the air flow sensor to a little valve thing . less than a quid to fix Quote Link to comment Share on other sites More sharing options...
bear Posted October 2, 2013 Share Posted October 2, 2013 Hi BusMan, I take it you mean the wastegate modulator & the three pipes? Griff Quote Link to comment Share on other sites More sharing options...
Andyru1 Posted May 17, 2018 Share Posted May 17, 2018 I am new here but have had a td5 for 7 years.As the author said i had surging under acceleration and very poor acceleration. Ok for overtaking a tractor but cyclists were leaving me behind. OFF with the old heat shield and What! A completely siezed waste gate valve. Lashings of plus gas and wd40 later plus lots of arm wrestling, voila, smooth and soft. I had forgotten how fast it would accelerate, imagine the scalf and googles as the wing commander says "cabbage patch coming over the brwiny (sic)" Or "Have you ever felt the wind through your hair?" FART "well he has" (Dangerous Brothers and Black Adder) Yippee Thanks Guys Quote Link to comment Share on other sites More sharing options...
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