D4 Performance Restricted

[ZKEHY]

Hi everyone,

So I've done lots of searching and trying different things but can't find a solution, so here goes my first post on here. I've got an 09 D4 3.0 @ 105k, lately on occasion I have been getting the "Performance Restricted" flag, I haven't been able to find a pattern to it, but from my searching I think it could be the sticky secondary turbo isolation valve problem. Turning the car off, waiting a few minutes then back on will have the problem disappear for awhile. In attempting to diagnose if it is this I have been trying to see the valve in action, by revving the car with a camera positioned to capture it, but I can't seem to get it to move at all. This would suggest it was that, but, I'm not getting the error message at present. Basically what I'm asking is what conditions need to be met for the valve to commanded to actuate? I've just been blipping the throttle up to at least 3000rpm but it won't move but isn't giving an error so I feel like this can't be right. I also even removed the vacuum hose from the vacuum chamber and went for a drive with no errors.

So any ideas or suggestions?
Thanks in advance :)

[Graeme]

There is a procedure for testing it that involves disconnecting the valve'e vacuum line at the top front of the engine. However the access panel behind the front right wheel is quite easily removed which then allows you to use your hand to operate the valve's lever which is on the engine side of the valve. If the lever's movement is being restricted by grit then you will feel the stickiness of movement, which will be freed with a few movements of the lever and perhaps a squirt with a liquid (water?) to wash away the dirt.

Edit: Blipping the throttle or high engine revs without a load wont cause the valve to operate.

[ZKEHY]

Thanks for your reply. How hard should it be to move the valve, like it moves smoothly but it's very hard. As a further development, I got an engine management light tonight at the same time as the restricted performance warning, first time that's happened, does that give any further clue to what it might be?

[Graeme]

Perhaps coincidental but my D4 started with just the message occasionally then progressed to more frequently then the warning light as well over several days.

The valve isn't difficult to remove, held on by 3 bolts (IIRC) and 3 hose clamps to undo. Mine hasn't re-occurred since being cleaned but I expect it will when enough dirt accumulates.

I targeted this valve because mine's several fault codes all related to inlet air pressure discrepancies and there were reports of this valve being a regular culprit.

[ZKEHY]

So I took it off and gave it a good clean today, mechanism was working nice and smoothly so I had my fingers crossed. Low and behold restricted performance has shown again. I've noticed that usually it is occurring after slowing from a run above 70kph with the RPM always below 2000. With no knowledge of how the vacuum system in this vehicle operates I'm wondering if it could be something to do with that and it operating the actuator. I say this because I've also noticed recently, sometimes around when it happens, the brake pedal loses its feel, to the point where pedal travel can almost be to the floor before they bite, if I pump it slightly a couple times though it returns to normal? Could this be related?

Cheers

[Graeme]

Your brake pedal behaviour is far from normal.

There are lots of causes of restricted performance so fault codes need to be read. I had one recently that emanated from the gearbox ecu (TCM) triggered by a gearbox malfunction. Your's may be due to a disconnected vacuum hose somewhere or perhaps the primary turbo's actuator rod joint being sticky.

[ZKEHY]

Is the primary actuator rod the one on the pax side of the engine right next to the battery compartment, black plastic rod?

How much should it be to get codes read, LR here in Perth wanted to charge $170 for it! Seems a bit much just to plug the thing into a computer.

Is it possible these issues are related? The brake pedal thing isn't all the time, in stop start traffic it's not there because you're constantly on and off the brakes, but after a run up the freeway braking on the offramp will be where it's worst, then "Performance Restricted" often follows.

Thanks

[Graeme]

The primary turbo is on the passenger side and the rod is at least visible under the mudguard over the top rear of the wheel but may also be visible from above. I don't recall its colour but I was able to get to mine to check that its joints were free to move.

The 2 faults may well be connected but I would be pursuing the brake pedal misbehaviour which may lead to uncovering a disconnected vacuum hose somewhere.

You would do well to purchase a code reader tool specifically for the Disco because some problems are easily solved once the codes are known. You can also get remote advice from knowledgeable people on possible causes if the codes are known. Some tools only read and clear codes whilst others allow some settings to be changed. Depending on what you see yourself doing, spend less or more but only do it once.

[gghaggis]

Is the primary actuator rod the one on the pax side of the engine right next to the battery compartment, black plastic rod?

How much should it be to get codes read, LR here in Perth wanted to charge $170 for it! Seems a bit much just to plug the thing into a computer.

Is it possible these issues are related? The brake pedal thing isn't all the time, in stop start traffic it's not there because you're constantly on and off the brakes, but after a run up the freeway braking on the offramp will be where it's worst, then "Performance Restricted" often follows.

Thanks

I can read the codes for you - we charge $30. PM or email me.

Cheers,

Gordon

[ZKEHY]

Thanks for the help guys.

Will PM you Gordon

[ZKEHY]

Thanks Gordon for checking my codes today.

We discovered the likely culprit was this code P0033-00 (28) - Turbocharger Bypass Valve Control - Circuit open.

Does anyone have any ideas what this could be? Where I could start looking?

Cheers

[Graeme]

That sounds like the solenoid that controls the bypass valve.

The vacuum line runs up to the top of the front of the engine from the air valve below and connects to a solenoid that controls the vacuum flow. Have a hunt around to see if you can spot the solenoid and check its connector and nearby wires.

[ZKEHY]

I feel like we're getting closer and closer to a possible solution here, is this where I should be looking?

Thanks

https://www.aulro.com/afvb/images/imported/2015/02/290.jpg

[Graeme]

In the right area but you need to be sure that the hose goes down to the isolation valve. How many solenoids just there? Can you disconnect and reconnect all electrical connectors in the vicinity?

I can't help by checking mine as mine's having a holiday at the mechanics.

[Ferret]

I feel like we're getting closer and closer to a possible solution here, is this where I should be looking?

Thanks

https://www.aulro.com/afvb/images/imported/2015/02/290.jpg

I have had a similar problem.

3.0l Turbo malfunction (http://www.aulro.com/afvb/d3-d4-rrs/177883-3-0l-turbo-malfunction.html)

[Graeme]

I remember that one!

The other solenoid is for emission control and is only available c/w hoses according to the parts manual.

Spray the contacts with contact cleaner/lubricant for starters.

[ZKEHY]

So I've had a poke around and everything looks ok in there, all the hoses were fitted alright and the connectors were good. Car is booked in to the mechanics for an engine and trans service on Friday so I'll see what they say about it and update on here when I find a solution. All I can seem to find on the net relating to the error code is relating to Saabs.

[Ferret]

In my case it was not a hose / connection problem. It's a vacuum operated switch. The switch had failed - it's an electrical problem.

[ZKEHY]

Soooo, interesting visit to the mechanics today. They pulled 5 turbo codes (worth mentioning, since the last code clearing reset I had got the rarer engine light plus performance restricted the night before and decided not to clear that one even though I think it's causing erroneous codes). They said the codes would indicate requiring a DOUBLE turbo replacement, but they weren't convinced. They said the secondary turbo was bypassing oil for which there was a modification they could do that would hopefully fix it. Other than that they cleared the codes and said bring it in when they reoccur (which the restricted performance did 10 minutes after leaving, no engine light though, would have liked to take it in right then but they'd closed). So any thoughts on these developments anyone?

(Also the issue with the brakes was because the pads were getting low, had them all replaced and it's perfectly fine now)

Cheers

[Graeme]

What's the cost of a new solenoid for the isolation valve? For a relatively low cost and being quick to fit I would be more than asking for it to be replaced.

[ZKEHY]

Yeah that was my exact thoughts, I'm going to order one after the long weekend and just fit it myself. Fingers crossed

[ZKEHY]

Ok so I have noticed something else interesting, it appears my faults could be affected by ambient temperature, I do most of my driving at night, when the temp is below 30c outside, "Performance Restricted" occurs regularly. However, during the day, with temps above 30c, no matter how I drive, whether like a granny or really working both the turbos, nothing. It's perfectly fine. Does this point further towards the solenoid? Surely if I was in more major trouble and in need of a turbo replacement/replacements I would see other issues? Lack of performance before errors occur, smoke, weird noises etc etc?

Also, I'm not sure if I've mentioned this, but I never have had any smoke at all, if that helps this mystery at all.

[Graeme]

Improper electrical connections can be affected differently for different temperatures. Has the earlier fault indicating a failed valve circuit re-occurred?

The part is LR021929 and costs about 20GBP in the UK.

A quote from a Disco3.co.uk thread: recommend you D4 owners get a spare one as this is what can kill your secondary turbos if it gets sticky!!

Smoke or lack thereof would not be conclusive especially if the engine operates correctly often enough to not allow any build-up of oil.

[brad72]

I also recently had the restricted performance light come on on my D4 TD2.7. At first it was only every now and then but soon happened a few minutes after starting. It never went into limp mode but steadily I got more and more black smoke billowing from the exhaust whenever I accelerated. Great way to make the tailgaters back off mind you.

Culprit was a split turbo intercooler hose that goes into the inlet manifold. Split was around 2" long. As a temporary measure I cleaned it with alcohol, glued the split with Loctite instant adhesive and put some duct tape over for good measure. Instantly the Restricted Performance code was gone and no more smoke.

This may not be your fault which I hope you track down but it might help others.

[Graeme]

My 3.0 had restricted performance today, caused by the water in fuel sensor wire not making contact at its connector. Its great to have a diagnostic tool to read and decipher the codes.