Thread: Sticky primary turbo actuator - external fix?

Update - Swapped over the secondary actuating solenoid with my spare unit last night. Checked all the air lines, no blockages or leaks as far as i could determine. This solved the P22 error codes, and had full power during the test drive. But now I've managed to get a code relating to the EGRs, didnt record the code as i cleared it in order to get home. Will ry to replicate the error code and post it here. I now believe that my EGR valves are failing..

Originally Posted by Disco4TT3

My Disco 4 3L TT also hit Reduced Performance mode recently with fault P22D2-77 logged, which translates to "turbo actuator stuck open". For me it was the secondary turbo on the right hand side and only noticeable under heavy load or acceleration.

A couple of mechanics looked at it and quoted on replacing the actuator rod assembly with a service kit or the entire turbo at costs ranging from $1k to $4k.

Ended up fixing with WD40 and a screwdriver without removing anything.

Well worth taking a look in the engine bay after you look at the computer screen.

Hi, Any chance you could explain exactly how you did the fix, please, as I've hopefully isolated the same problem on my Disco 4 to being the same as this. Any help gratefully received here in the UK!

Sad to say it was wishful thinking that the spray fixed it - the issue recurred. I ended up having to get the turbo wastegate changed which was clogged with carbon gunk. Apparently there are kits you can get for this. But it’s a big job which was out of my league.

Originally Posted by Disco4TT3

Sad to say it was wishful thinking that the spray fixed it - the issue recurred. I ended up having to get the turbo wastegate changed which was clogged with carbon gunk. Apparently there are kits you can get for this. But it’s a big job which was out of my league.

Theres cleaners specifically for diesel turbo engines that is supposed to clean up the intake tract and de-coke the wastegate(s) etc.

See Pro Strength Diesel Turbo Cleaner - 500ml | Supercheap Auto

Get the EGRs deleted will save a lot of deposit build up that can kill turbos.

Originally Posted by Graeme

All better now. The cause was a sticky secondary turbo isolation valve that was still stuck open until the rod on the vacuum chamber was touched. After going for a short run to confirm the fix, the valve body was removed to reveal dirt jamming between the linkage plate and the housing. A good squirt with WD40 and its all clean until next time when I'll just do the squirting with the housing and hoses still in place.

The valve is located behind the right front guard behind the plastic cover at the very bottom front. With the vehicle at off-road height and wheels hard right, access was quite reasonable. I'll grab a pic before refitting the cover.

Edit: A post on Disco3.co.uk referred to the same 4 fault codes that caused the LR techo to immediately identify this valve as the cause.

Yes this is a fault that i've had come in a few times. Symptoms can be oil being pushed into the air filter from the secondary turbo.

I remember wondering what might cause oil to get back into the air-box when first investigating the fault.

Originally Posted by Graeme

I remember wondering what might cause oil to get back into the air-box when first investigating the fault.

From my understanding, if the turbo drain pipe mod has not been done, the oil from that drain makes its way past the turbo plain bearing, into the clean air side into the air control valve and intercooler, and eventually into the airbox. Moving the drain point higher up the block allows the pipe to drain and no oil back pressure at the turbo, solving the issue. I used to collect about 1/2 cup of oil every 6 months from the intercooler lower hose, and clean out the air control valve at the same time. With recent sec turbo replacement, this included the turbo drain mod, and im assured that no more oil into the intercooler and clean air side from the turbo.

EGRs is another story

IMO moving the drain higher isn't the reason why oil accumulation is avoided, more that the scavenger pump for the original drain stops as soon as the engine stops yet there is still pressure for several seconds in the turbo oil feed line which has to go somewhere so gets through the shaft seals, which aren't designed to withstand pressure, into the air supply side.