Turbo or Egr

[Mark Stewart]

Hello,
I am hoping one of the disco fundis on here might be able to assist.
My 07 tdv6 with 156k on the clock started with the Engine System Fault story, but only when under full demand and at around 3500 to 4000rpm. Took it to a dealer, they said Egr valves, so I blanked these and cleaned the sensors.
Fault continued but now code P2290. Again to dealers, they said it needs the egr's and this will fix the problem, but won't guarantee.

Took it too a friend mechanic and went for a drive while plugged into a diagnostic computer to check boost pressure, ESF comes in when boost hit 22.6 psi, which seems far to high and suggests new turbo.

Problem is, both are expensive items and probably only one is causing the fault. Any ideas / suggestions please?

[hgbosch]

Hi Mark

this looks to me like a carboned up actuator ring of the turbo.

VERY EASY to fix.

1. Add 1 litre of Sasol or Caltex 2sO (from the forecourt) to the diesel tank and fill up.

2. Drive tank out and repeat point 1.

3. Ditto 2 and add 500ml of 2sO and with every fill up thereafter.

This will be your cheapest turbo fix ever.

And do it quick, before the turbo actuator motor burns out

[hgbosch]

Hi All

for general information:

1. 2sO lubricates the injection components and therefore substantially increases their life span

2. JASO-FC 2sO added at 1:200 ratio will remove any existing carbon deposits and prevent the formation of new ones.

But this only works if 2sO is added with EVERY fill up.

[Mark Stewart]

Hi George,

Thanks for your response, I have read your earlier threads about 2so and did try this a while back, and am still using it, however problem remains.

Perhaps it was to late? Question - could the non function of the egr's have anything to do with the turbo over boosting?

Thanks

[hgbosch]

Hi Mark

unless you add 450-500ml of JASO-FC 2sO with EVERY tank filling, 2sO will NOT give you the de-carbonizing effects.

So just add 1 litre for 2 tank fillings in succession and your problem will resolve itself.

If you don't believe me ask Baben how we solved the issue with the D3 from the Swiss Embassy 2 years ago

[Koos Best]

Mark, did you guys remove the butterfly in the air box when you blocked off the EGR?

ALSO

Check the actuator movement on the turbo , maybe its sticky, George's remedy usually works, but just make sure it moves freely.You can do it with bloudraad, just check on D3.CO.UK

[DiscoFrans]

Mark,
Koos's advice is spot on!Whith the heatshield removed,let someone cycle the key and you should be able to see if the actuator motor is still OK.On switching on it should cycle x 3
Good luck,
Frans

[hgbosch]

Hi Discofrans and Koos

but even if the actuator lever moves, that is no guarantee that the full movement is guaranteed. The hesitance or failure for the actuator ring to return from the full open position will result in the warning light coming on.

If there is stickiness towards the full open position (common) then the lever will not return and overboosting will result.

Just to illustrate here are two pics, the blocked one courtesy of Stallion Turbo and the clean one came out of Swambo's car, when the turbo failed due to excess heat radiation from a blocked cat (just soon after we bought it. I had the cat cut out, but the damage was already done.

Check the squeeky clean contact surfaces, where the actuator ring levers pivot. This naturally due to 2sO

[Koos Best]

George, that';s my point, try and move the actuator by manual force to see if it moves the whole way, maybe Mark must check it and lubricate it while moving with WD 40 as per the UK site.

George just off the topic, gave a friend your 2SO advise, to put on overdose on his lethargic hilux 2.5 d4d , he claimed it improved after the 1 st tank and by the the next 3 fill ups car nearly back to normal , but a vast improvement.

[DiscoFrans]

George,
Not disputing the advice to use 2So,but if the actuator motor is already burnt out,no amount of 2So will fix the problem!
Regards,
Frans

[Mark Stewart]

Hi Guys, thanks for all the advice, I will remove the heat shield and see if the actuator is moving. In the meantime will up the 2so dosage back to 1 litre.
Will also check if butterfly has been removed.
Unfortunately will only be able to check on the weekend, but will let you know what I find.

[hgbosch]

George,
Not disputing the advice to use 2So,but if the actuator motor is already burnt out,no amount of 2So will fix the problem!
Regards,
Frans

Hi Frans

if the stepper motor is burnt out, then there will be no controlled movement of the actuator pivot arm!

As this motor is not available loose, a new turbo would be called for.

We had the turbo exhaust housing ceramically coated. Before this was done, the actuator ring mechanism was taped off to prevent the coating to get in there.

Ceramic coating of this housing and the exhaust manifolds achieves two goals:

1. Faster spool up of the turbo

2. Less heat radiation to the turbo bearings and stepper motor. This together with 2sO will result in a turbo live span of some 350'000km or more.

Swambos D3 sits now on 203'000km and still runs on the original stepper motor

[Mark Stewart]

Just in case, any one is interested, the problem turned out to be what looks like a clump of grass in the fuel filter. How that got there I have no clue. Anyway Disco is all good now, and during the process I got rid of EGR valves and the CAT, which does make the disco breathe a lot better.

Thanks for the help guys.

[NS406]

Thanks for the feedback. Always nice to hear and learn from the outcome. Nice ending.

[Baben]

P2290 relates to fuel rail pressure. That's why the fault codes are there - to help you find the issue.
My question is why didn't the people with the diagnostic computer tell you this?

When you get this error first step is always new fuel filter, then check lift pump in tank and then the real expensive bit - the HP pump on the engine.

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[Landyluvver]

22.6 psi is around 3.3 bar which is far too high
either the reading is inaccurate or you have a serious turbo problem
with that sort of boost i guess it goes like a rocket

[Wessl]

22.6 psi is around 3.3 bar which is far too high
either the reading is inaccurate or you have a serious turbo problem
with that sort of boost i guess it goes like a rocket

Hi Landyluvver. As far as I am aware of 1 Bar is equivalent to 14.5psi. That will make 22.6psi around 1.56 Bar. I am not sure what the Disco 3's turbo boosts to and cannot comment on it being high or not.
For info, I have removed the cat on my D3 at 133897km's and was quite surprised to see that the cat is not overly dirty in that the soot evident was very soft and not blocking off any passages in the cat's mesh. However I do find that the motor is a fair bit more responsive and having a nice little V6 groal to it. Makes the right foot quite heavy and needs to be careful not becoming a "wintie"

[Baben]

If you are taking the reading from the MAP sensor, which most diagnostic units do, the reading will be absolute pressure and generally peaks at 2.2 bar (32psi) standard or 2.4+ with a remap. Subtract ambient .9-1 bar depending on your altitude, and you get the boost value 1.2-1.3 bar (18psi)

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[Baben]

What I mean is, you want to see a peak pressure of 33psi around 2800rpm 3rd gear wide open throttle

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[Wessl]

Thanks Baben, makes a lot of sense.