Hi found a possible fix for TD4 2000 rpm misfire and smoke issue

Hi guys been looking around on the forum when I was trying to find a solution to a missfire that affected all cylinders around 2000 rpm on a TD4 freelander. Vehicle concerned is a 2005 td4 auto at 82000 miles. Was very bad white/blue smoke while driving and a jusddering like driving on concreate roads. On a smooth surface. 60mph toeing on motorway was horrific lack of power causing irratic gear change due to power loss on auto gearbox.
Obviously being a workshop I have access to lots of diagnostics equipment including snap on and Hawkeye. Leak back testers snap on scope for electrical testing vac testers and smoke testers. All of this however was rather irelivent in this case as the vehicle had no fault codes apart from a fuel preshure code for delivery fuel preshure which was solved by replacing the lift pump ( fuel filter also changed at same time.)
Vehicle also suffered from a bad connection to the rail preshure sensor. Which both the sensor and loom were replaced. Also fitted was a Bosch maf a new boost solonoid and full service items. Compression was around 300( from memory) on all cylinders which ruled out a compression issue on one cylinder.
Diesel injectors were both leak back tested continuity tested and load tested with the scope apart from marginally more on fuel returned on injector 2 all were around the same. (5ml more on 2 over 3 min test.)
This lead me to believe either all injectors were operating ok or all were faulty at the same rate. The latter although possible is unlikely. Meaning injectors were probably not the issue. I then smoke tested the vac and inlet systems and other than a pinhole size leak on the intercooler core showed inlet tract and vac system was intact. Meaning this common issue was not the cause off my missfire. I will later be changing the boost pipes and vac lines as there now 10 years and showing signs of age cracking and ware. But for the point of this they are ok.

While down there I noticed that the turbo VNT actuator arm was not in the position that I thought it should be so I removed the actuator hose from the boost control solonoid and using a vacuum/preshure hand pump I applied vac to the actuator. The arm moved as it should releasing vacume returning to the stop position. The actuator could be marginally pressed by hand. But still looked wrong. I then applied a small amount of preshure to the actuator to see if it moved the other way. (outwards) And it did. I tried leaving actuator off and revving car and it was better but still the miss was present. The VNT actuator had pushed back in slightly. Upon further inspection the VNT actuator return Spring has gone weak. Not allowing the VNT fins to return to the off vacume position. I removed the accuator and worked the accuator and the VNT arm freeing both up. Reassembled reved to 2000rpm and no missfire. Took for road test. Power was up massively
Time will tell how long this will last for and the accuator return Spring has gone soft. So the slight sticking of the VNT vanes will cause this not to return to its non vac position. I did think of adding a spring to the arm for extra assistance. But if it stays fixed will probably. Just have turbo reconditioned by turbo technics. At which point they fit a new actuator as part of the process.
Hope this helps others maybe find a solution to there problem.
Cheers Chris

Thanks for the advise, look like I have the same fault, though at present for us it points to injector number 1, but if that's not the case this would be the next thing I would be looking at.

Is it simple enough to test?

Thanks

That's quite an explanation, but needs to be in the Freelander forum.
Welcome to the forum.
I'll see if Beastys online to move it.
Mike

not heard of this one before but great to know

1997 Discovery said:

Thanks for the advise, look like I have the same fault, though at present for us it points to injector number 1, but if that's not the case this would be the next thing I would be looking at.

Is it simple enough to test?

Thanks

Click to expand...

Get on back just behind front undertray there's a opening where the exhaust comes through.
Above transfer there's the turbo. The actuator is the part with the blue/black vacume pipe going to it. Remove the vacume pipe from the boost solonoid to release and trapped vacum. Try pushing the actuator upwards towards the sky. If it moves up more than in the spring has probably gone weak in the actuator or the VNT in the turbo is sticking. If when you remove the Center vac (turbo one) from the boost control solonoid there is a hiss this might also be a fault with the solonoid or the filter release line may be blocked. When you lake the actuator pipe off look at the arm to see if it moves upwards at all. Actuator arm on mine was very rusty where it entered the diafram bulb. And was sticking there also. I cleaned lubricated and alternated between preshure and vacume until it became free again I used a vacume hand pump but there are other tools that will work. Large srynge etc.

I would like to remove turbo compleatly and check all VNT vanes internally. As not entirely sure if it's actuator is the cause or if it's gone weak from years of VNT stiffness. But it looks like a bugger of a job to remove turbo compleatly.

vrdynotuning said:

Get on back just behind front undertray there's a opening where the exhaust comes through.
Above transfer there's the turbo. The actuator is the part with the blue/black vacume pipe going to it. Remove the vacume pipe from the boost solonoid to release and trapped vacum. Try pushing the actuator upwards towards the sky. If it moves up more than in the spring has probably gone weak in the actuator or the VNT in the turbo is sticking. If when you remove the Center vac (turbo one) from the boost control solonoid there is a hiss this might also be a fault with the solonoid or the filter release line may be blocked. When you lake the actuator pipe off look at the arm to see if it moves upwards at all. Actuator arm on mine was very rusty where it entered the diafram bulb. And was sticking there also. I cleaned lubricated and alternated between preshure and vacume until it became free again I used a vacume hand pump but there are other tools that will work. Large srynge etc.

I would like to remove turbo compleatly and check all VNT vanes internally. As not entirely sure if it's actuator is the cause or if it's gone weak from years of VNT stiffness. But it looks like a bugger of a job to remove turbo compleatly.

Click to expand...

Couple of photo's to commend the above, thank you for sharing

don't know if it's any help but , at 50 mph the hippo had a bad flat spot, around the 2000 rpm mark when I belive the turbo comes in ??

noticed that my vacuum hoses were perishing and split

especially near the turbo solenoid and also where the hoses go in front of the engine block near the vacuum pump

I bought all new silicone vacuum hoses and replaced the lot , a lot cheaper than buying oem ones

when I watched the turbo solenoid arm it was intermittent and replacing the hoses cured the flat spot

after that I done the egr bypass , updated the crankcase breather with the bmw type and lastly fitted a synergy box which I may add transformed the engine , replaced fuel pump and filter, with oem type

done it in stages to ensure all faults were gone before fitted the synergy box, otherwise it would have made any faults worse

of course don't know if it's the same for ur good self but just wished to share in case something like this is also happening to urs


all the best

This vacuum hose split thing seems to be the cause of this 2000 rpm flutter, looked at a FL the weekend and it's pipe was split by the EGR valve resulting in a loss of vacuum which would stop your turbo boosting properly

This diagnosis has one large hole in it. Leak off testing is only a small part of injector diagnosis,spray pattern etc is equally important and can only be checked on a test bench. A jammed or non working vnt actuator is only going to cause under or overboost depending on where it is stuck.

Quite right about the injectors but if a boost pressure is wrong say at a given engine and vehicle speed then the ECU could throw a wobbler and give out some random settings

No, the ecu will just use the readings and calculate injector duration. Even if the VNT control is stuck in full boost conditon the engine will struggle to overboost until about 70mph in top gear - hence the thread on it. With the linkage stuck in a low boost position the engine will just lack power as the ecu will see a low Map reading, and also low Maf reading so will not need to use smoke limitation.
The rough running is much more likely to be the injectors.

Obviously you know more about the FL mapping so tell me why when I fitted new vacuum pipes to replace a broken one at the EGR actuator the 2000 rpm flutter vanished and the engine had no smoke when engine RPM was held above 2000 ? There seems to be some conflicting evidence of what people are told and what some people have done to eliminate this syndrome, we are all trying our best to overcome this and some of us have actually cured it without injector replacements and other expensive bits and bobs that garages have replaced with no prevail. It is one thing to plug a machine in and another thing to actually find and fix a fault when no codes are present and values are reading normal

I cured mine simply by reinstating the EGR valve. I've not done anything to the injectors or feel there is a need too. With the EGR blanked, I was getting a misfire at 2K Rpm on a trailing throttle or if the revs are held at 2K in neutral. There was no sign of misfiring at any other time.
There's definitely something that the ECU doesn't like in this instance, which I think is confusing it.
I'm not a great authority on common rail diesels other than the basics though.

Obviously a preshure problem.

Hi All, I'm new to this forum and also a newbie FL owner (since Dec 2016).
I've read a number of replies on this topic here and on a few other threads and the one thing that amazes me is the broad range of possible causes - does anybody have any suggestions as to what I should look at next?
My '05 plate FL (BMW engine) is currently suffering with turbo flutter whilst driving, however when the car is cold and I hold the accelerator at ~2000 rpm, the car engine judders slightly (like a small mis-fire) and a shed-load of grey smoke comes out the exhaust. The turbo flutter is more noticeable when the engine is cold. After a few minutes of driving or when the engine is warm, there is no smoke or misfiring but the turbo flutter is just audible.
I've had a full set of injectors (re-con), vnt actuator and had the turbo bench cleaned and set-up, new vacum boost solenoid fitted, new fuel pump (tank end) and a new oil cooler (not related to this issue ... I think!).
I left the car at my local garage last night so that they can experience the flutter / smoke 1st hand when the engine was cold. I left the garage 1 1/2 hours later this morning none the wiser, only to be told that "they're not sure what to do now"!
Do any of you intelligent chaps out there have any suggestions as to a possible solution? I read in this thread that 1 possible soulution would be to replace all the vac pipes ... I will look at this over the next few days. The other suggestions was to reconnect the EGR vac pipe (mine is disconnected and bunged with a bolt!).
Thank you in advance.
Cheers, Steve

The truth is, no one really knows why some TD4s suffer the 2K misfire and some don't.
My own TD4 isn't doing it at the moment.
However my EGR is now disconnected. The only change I made, was to add the Rover Ron recommended Peirburg MAF and set the Synergy up accordingly. It's also set on setting 9, because I like the power that gives.
I'm happy that my 2K misfire has now gone. As to the exact cause. I just don't know for sure.

Turbo flutter can be a leaking vac pipe. They do chafe where the pipes run over the engine.

Did you have the EDC recalibrated to the new injector specs?


Ps. There's no need to tell the FL forum that the engine is a BMW. It's something that some of us don't like being reminded of. It's a lump of junk in my opinion. It's unfortunate that it found it's way into the Freelander at all really.

Thanks for your feedback Nodge68 ... including the BMW engine reference! I've ordered a manual vac pump so will test the system over the weekend.
Ref the recalibrated injectors ... sorry I have no idea, the garage replaced them. If you have any onfo on this I'll take a look at it and will ask the relevant questions.

My feeling is that its down to the behaviour of the injectors.I got fed up with recon injectors from various suppliers and ended up using only genuine Bosch units.This has sorted all of them so far. Just today I had an enquiry for a TD4 that I worked a load of snake oil into 6 months ago and it was fine til now.(Wynns injector cleaner) I guess the needles are sluggish and don't open and close cleanly.It all needs to be very accurate to work properly...
BTW Nodge, totally agree about the BMW engine,far from the best.But my wife has been driving a £400 TD4 for about 3 years now,engine is doing well !