Location of Suction Control Valve on a V9X Engine

[spiezzy]

I will also Add that there is no need to remove any af the intercooler plumbing just the air intake hose and 2 brackets with hold the fuel hoses don't need to disconnect any fuel hoses and there is a wiring harness which is held by a couple of clips just unclip and move out of the way you will need a T25 Torx head and a long extension to get in there and a telescopic magnet to put back in my alternative was a small piece of Blue tac on the Torx bit did the job perfectly
hope this can help someone in the future
cheers Pete

 

[Mark s]

Sorry to resurrect an old thread but wondered if you could tell me, or even photo if possible, where exactly the scv is on the v9x engine. Have a feeling mine has died as the truck won't fire, it has the 0089 code up. Any help is much appreciated. Cheers, Mark. Oh I'm from the UK so sorry if I am late with any replies to you.

 

[Cgrigg]

The SCV (if yours has one, which is likely) sits on the top of the pump, at about 1 o'clock as you look at it from the front. It has a black electrical connector on it.

I wouldn't suspect the SCV for smoke straight away, as Manning says. I'd look at air filter, MAFS clean (it's in the air intake, unlike the YD25, yours is part of the air tube itself just outside the air filter). You MUST be careful with this. Do NOT EVER poke anything into the MAFS. You can spray it with electrical contact cleaner, but don't touch the innards, it's extremely sensitive (and expensive). If the MAFS is dirty, it will report the incoming air stream incorrectly to the ECU and the ECU will calculate fuel and boost incorrectly.

You could whack a Bluetooth OBD adapter (ELM327) in and watch your boost pressure. The V9X should easily produce 20psi of boost. If you're not getting that, and boost pressure doesn't rise fairly quickly when your engine revs climb, your turbocharger might be less responsive than it ought to be. This will probably be a bearing issue, and may show itself as a sloppy impeller/turbine shaft. This shaft shouldn't wobble, if yours does then your turbocharger may need replacing.

As Manning says, checking the air path is important. Also make sure your battery terminals are nice and clean as erratic electrical connections can cause problems which might result in commands to the turbocharger or fuel system not being as accurate as they ought to be.

 

[Cgrigg]

Hi Old.Tony Thanks for your recent replies. So I know that the genuine Nissan Part number is 1665200QAA and the Bosch part number is 0928400777.

My SCV is the Bosch item. So my question is - do you think that because my SCV has the Bosch part number- the original Nissan SCV has already been replaced OR do you think it is possible that it came out of the factory fitted with the Bosch SCV? Hope that makes sense.

Also 1 have attached the below pics to show anyone where the SCV is located if that helps.

Cheers
CG

 

[Old.Tony]

It's difficult to say. My Yamaha FJ1200 had a Mitsubishi fuel pump. It's a matter of cost+availability of supply vs cost of engineering it yourself, I guess. I doubt my own original SCV (which I don't have any more) was a Nissan-manufactured part.

Hell, even my snorkel that has "Nissan" on it is just a rebadged Airtec. It's often cheaper to buy a badge than to engineer the whole thing!

And just because Bosch made the VP44 fuel pump (some D22 models have this and it's reliability is questionable) doesn't mean that everything they make is bad. The SCV experiences we've had may have had something to do with fuel quality - Australia doesn't have the best fuel in the world.

 

[Jamesltu]

hi to all well I changed the SCV on the V9X and it took around 40 mins pretty straight forward I noticed in the old one on the connection plug inside it had diesel in it replaced with new Boach one and it seems to run a lot smother and much less smoke when flooring it (not that i do that all the time) put the old one under a micro scope and looked deep inside the plug and noticed a crack in the plastic so I would say it was ready to fail at some stage but all good now runs like a dream thanks again Tony for your help
cheers Pete

Hi mate i have same problem, need your help, where scv in v9x and if you have link for bosch scv much appreciated

 

[Labsy]

Hmmm... isn't this the sucker we are talking about? Interesting, I changed mine 3 times in a row, first 2 replacements were faulty new, while the 3rd one worked just fine for 2 months, now it shakes like phone on vibration and emits buzzing sound, which can be heard quite loud in the cabin.

What's then the valve 2 posts above, in the right part front side of engine?

 

[Andy.ob]

Hmmm... isn't this the sucker we are talking about? Interesting, I changed mine 3 times in a row, first 2 replacements were faulty new, while the 3rd one worked just fine for 2 months, now it shakes like phone on vibration and emits buzzing sound, which can be heard quite loud in the cabin.
View attachment 38169

What's then the valve 2 posts above, in the right part front side of engine?

Ill be keen to know about the buzzing sound as i just replaced one which was making the same noise for a genuine nissan one. So far so good…..

 

[Fivefivezero]

That's the turbo boost control valve.

Hmmm... isn't this the sucker we are talking about? Interesting, I changed mine 3 times in a row, first 2 replacements were faulty new, while the 3rd one worked just fine for 2 months, now it shakes like phone on vibration and emits buzzing sound, which can be heard quite loud in the cabin.
View attachment 38169

What's then the valve 2 posts above, in the right part front side of engine?

Mine had the buzzing sound which you could hear in the cabin, driver side

 

[Labsy]

I am a bit confused.

The mushroom-like valve on my picture, with vacuum line input and vacuum connection to turbo actuator, is electronically managed and as I understand,,this is SCV, Solenoid Control Valve.

But few posts above you were talking aboit SCV, which ahould be located in front of engine.

Are those 2 different things, or just different configurations in different engines?

 

[Rice]

@Jamesltu, if you look at the engine from the front (V9X) on the right hand side (wheel side) of the engine, near the front, gently move the plumbing out of the way, you will find the SCV. DO NOT DISCONNECT ANY OF THE PLUMBING. It has one electrical connection and a 10mm bolt holding it in. The V6 and four cylinder SCV's are vastly different and not interchangeable. Navara Parts have genuine Nissan part and are reasonably priced.

 

[Rice]

@Labsy, the "mushroom" is the VACUUM BOOST SOLENOID for the TURBO. The buzzing sound means it is working!

 

[Old.Tony]

We also need to get terminology correct to remove confusion.

SCV = Suction Control Valve, it's part of the fuel pump, often an issue on the YD25 engine. It is literally bolted to the fuel pump itself and only has an electrical connection.

BCS = Boost Control Solenoid, it controls vacuum levels going to the actuator of a variable-vane turbocharger. This can basically sit anywhere, has an electrical connection and at least two vacuum hoses depending on the vehicle, one of which will go directly to the top of the actuator on the turbocharger.

Just trying to remove any confusion - there's nothing like walking into the store to get a set of brake pads and walking out with hemorrhoid ointment!

 

[Labsy]

Thank you for clarification, @Old.Tony!

 

[Fivefivezero]

I did a scan through the EM section of the manual and there is no SCV for the V9X.? Only YDs

 

[Rice]

It is just behind the fuel pump RHS engine from front, heaps of plumbing in the way.This is what it looks like...........
Have a look up this page at post #31.

 

[HoneyBadger]

So, keeping the thread alive as this is such a common issue…
Really struggled to find the info I needed to do this job. I have a 2007 YD25 Spanish built D40. Due to its position, any video I found online regarding removal/refit of the SCV lacked clarity so I’ve attached a couple of pictures to help explain. It is a sod of a job unless you have arms like a child and your left elbow folds both ways. All you need is a normal 5mm Allen key but preferably a small ratchet with a bit length of about 25-30mm, a 10mm ratchet to remove the dipstick tube retaining bolt and a narrow beam torch. I’m not the tallest so a short platform really helped me out. Unless you’ve got a 1/4” torque wrench you’ll have to rely on your super powers when knowing how tight to do the bolts up. The videos I saw made it look to me like the valve was fitted transverse. That didn’t help in locating it, if you’re struggling- find the loom, follow the branches and you’ll find it sitting parallel to the engine in the back of the fuel pump. Don’t start the job at 8pm unless you have an indoor work space but I can’t leave a parcel unopened, really it’s a Saturday morning job.
I found the genuine Nissan/Denso part on
e-bay A6860-VM09A. Took about 1/2 hour to do plus an hour faffing about finding it and getting the Allen key in there to start with. The orientation of mine was with the plug furthest away from me. I put the bolt closest to the engine block in the valve before inserting it to keep the gasket in place, the second bolt is much easier.
Hope the war story helps someone!

 

[HoneyBadger]

An update to my previous post…
Nothing but problems since changing the SCV for a ‘new’ one. Sourced from eBay in a genuine Nissan box with part numbers matching and exactly the same as the one I extracted. It was a beige cap, I didn’t know until later that I should have looked for the purple one.
I had a few issues to fix so ended up down the rabbit hole thinking I may have disturbed something, broken a pipe somewhere etc…
I kept the SCV I took out just in case- luckily. I plugged my OBD scanner in, showed no codes, done the pedal reset so many times I don’t have to look it up anymore, drove hard, drove gently but I was having all sorts of issues. Mainly turning over for longer before startup, rough running and loss of power up hills. Sometimes it would stall, sometimes it wouldn’t. No limp mode though. After cleaning the boost control solenoid out, the MAF and standing back for five minutes to reassess… “Put the old one back in?” I had only changed it due to the very occasional limp mode and had adjusted my throttle use to allow for it so it wasn’t a major issue anyway. Got the old one back in, jabbed and stood on the accelerator- again, fired straight up. Weird. Pulled out of the drive expecting acceleration like I was towing a warship then a surge at 2000rpm… smooth as anything. Went up a local byway, spinning wheels at 1500rpm in 2nd gear, happy and annoyed at the same time I went for a dual carriageway to see what the top end was like… easy! Moral of the story… if I ain’t broke, don’t fix it! Also don’t buy parts off of eBay…