2nd Turbo - Restricted Performance

[Dave King]

I’ve found that the restricted performance code is P22D3-77. Is there any way to check if the turbo control solenoid is working. I don’t know which of the two is for turbo 1 and which is for turbo 2. One on the left is grey and the one on the right is black. Any assistance would be appreciated 😊

[Graeme]

That code is for the secondary turbo's inlet isolation valve, sometimes called the air shut-off valve, which is located behind the bottom right of the radiators and accessed by removing the clip-on panel behind the front of the right wheel. The valve's vacuum tube runs up the front of the motor to where the solenoid is located at the top. You can reach in to move the valve's linkage by hand but may have to remove the valve by undoing the hose clamps and removing the 3 bolts, watching out for oil draining from the bottom of the I/C.
The early version of the valve was prone to having its linkage jammed externally by dirt whereas the revised version has a much more open pivot point that isn't nearly so prone to jamming.

[Dave King]

Hi Graeme, thanks for the valuable info. This morning I checked the two turbo solenoid valves using a 12v source, both clicking so I assume they are working. Last week I removed the plastic cover and removed the EGR assembly quite a lot of oil came out 😊. I didn’t see any fouling of the actuator linkage. Is there a way to check if the electrical side is functioning.

[Graeme]

I recall reading the LR test procedure but can't remember the finer points of the details. It involved running the engine at a specific rev and 1800 rpm comes to mind although 1800 rpm seems low to start opening the isolation (not EGR) valve. The solenoid hose is then removed, the solenoid hole blocked then check if revs drop/increase (I can't remember which) over a period which as best I recall is around 3-5 seconds to determine that the valve had been partly open. I may have all the specifics wrong but you could try such a test and if revs change when the hose is disconnected then the only conclusion would be that the valve had been partly open and therefore proves the point. If revs don't change then the revs may be too far off the mark, the solenoid valve could be faulty, the valve's vacuum chamber could be faulty or the valve sticky enough to not open when it should.

I had a MY10 3.0 D4 from new. After a couple of years I carried a spare solenoid valve because of reports of some failing and I didn't want to be stuck even at home let alone in the desert with restricted performance. I have already experienced the dreaded restricted performance while at home with a sticky isolation valve that I tracked down as the likely culprit rather than have my D4 trucked 200 kms leaving me without any transport on my farm.

PS. I must check to see if the D4's solenoid is the same as my 4.4 TDV8 L322's solenoid as the 4.4's solenoid valve is only available with the whole set of vacuum lines for the engine which is likely to be much more expensive than just a valve.