Power consistency question (survey) for Common Rail 3L owners ...

[Hodge]

I have a question or survey if you wanna call it for the CRD owners. I'm on a mission to eliminate the power mood swings my car has. Before my mechanic chucks it on the dyno hes asked me to ask others with a CRD how it behaves in terms of power consistency AND what and if any mods have been done, especially if the EGR is blocked.

So I need to know, is your power consistent ? If your EGR is blocked and if you have a chip and/or exhaust.

When I say consistent, I mean does it perform the same under different accelerations all the time. So for example, if you're on the same stretch of road everyday, same gear, roughly the same amount of pedal applied, will it give you the same power today as it did yesterday ? And not spongy one day and ok the next? Or takes of from one set of lights like a rocket, and it's extremely spongy the next set of lights.... ??

Here is my original thread: http://www.nissanpatrol.com.au/forums/showthread.php?23202-GU-patrol-power-mood-swings&highlight=Mood+swings

In a nutshell for those who can't be bothered going through that thread...
My car has tons of power. Most of the time... Sometime she becomes a slug for an hour, for a minute, for a day ... Sometimes a few days. Only to regain normal very responsive power, sometimes after car was turned off and on, or simply left overnight or simply at the next set of lights ...

When she does go into this low power mode, stepping on the pedal as I would normally, sends EGT's higher than usual and boost peaks.

So at the moment finger is pointed somewhere between the turbo/intercooler and air inlet... Something maybe is "restricting" the air into the engine "maybe". A swirl or butterfly valve or whatever it is maybe sticky. Don't know yet.

So a quick reply about power consistency of your CRD and what mods you have would be much appreciated! Cheers.

[Maxhead]

Mine is very consistent so I know how it's going to behave at all times but:

a) if I drop below half tank of diesel it gets more sluggish and will get worse as the fuel goes down. Lift pump would sort that out. Economy goes up
b) if air filter gets clogged I loose power and economy goes up
c) if I use diesel from any other outlet than Caltex I loose a bit of power and crap economy

I use on average 12.5l/100. Beaudesert 2.75 exhaust and no other engine mods. Tried EGR block but had some weird overboost issues so took it out.
Temps are around 400-500 deg C unless towing my 2.7t van when it can reach 600+

[Hodge]

Thanks so much mate. That's the sort of feedback I need.

[mudski]

Some good things Kris has mentioned there Eric. Particularly about where you get the fuel from.

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[Hodge]

Some good things Kris has mentioned there Eric. Particularly about where you get the fuel from.

Sent from my SM-P600 using Tapatalk

Definite good point mate. Unfortunately I eliminated this long time ago. Wish it was this easy lol.

[Maxhead]

Definite good point mate. Unfortunately I eliminated this long time ago. Wish it was this easy lol.


was thinking about this but have no idea, could it be an injector sticking , tps farking out occasionally ??? no idea mate but I hope you change the "common fail" to " common rail" lol

[Rock Trol]

Mine is very consistent as well but its also heavily modified. Even at the start (standard) it was consistent, especially after the intercooler was changed and the leaks where gone. Is your I/C in good condition?
The ECU controlled boost can sometimes play up but since putting a HPD Controller (Dawes) on it has become very consistent, just like a waste gated turbo. The only time I might notice a slight difference is when the weather changes such as cold vs hot vs rainy days where the air temp and density of oxygen can vary. Apart from that my CRD has always behaved. What you are describing is very strange. Is your boost always the same?
Maybe it is a butterfly valve in the intake. The ZD30's apparently have one so that they don't shudder when shutting down.

[Hodge]

was thinking about this but have no idea, could it be an injector sticking , tps farking out occasionally ??? no idea mate but I hope you change the "common fail" to " common rail" lol

TPS was replaced a while back as part of recall and car was doing the same even before that. This is definitely air/boost not getting into engine related. As when it does happen EGT's go much higher than usual and quickly, and boost also goes up too maxes at 20. This means turbo is working and there is fuel being pumped in, because there is boost there.


What you are describing is very strange. Is your boost always the same?
Maybe it is a butterfly valve in the intake. The ZD30's apparently have one so that they don't shudder when shutting down.

Thanks mate. Boost is always the same. As above when the goes good, even at low 10s of PSI she has heaps of power and EGT's are low 300s, 400 MAX up a hill @ 100km/h for example. When shes a slug, EGT's can get to 450-500 on a flat road even and boost hits 20PSI easy, and thats what the wastegate is set at. So the theory I think is, turbo makes boost, fuel is being pumped in to keep up with the boost, but the boost/air cannot get past a certain point after the MAP. So a valve "maybe" closing or sticking or something... Hence what we're trying to find out. THe dyno tune at JPC will put in gauge at the manifold it;s self and compare the PSI in the intercooler and in the manifold to see whats happening and at what times...

[Hodge]

Also Rock trol. Mine behaves the same as yours on a good day. Hot/cold she varies performance a little bit, which is expected, normal. But when this "slug" mode kicks in, it is really severe.

[jack]

Mine performs consistently day in day out, regular trips that include hills and never had an issue except once.

Towing the van up the hill out of Queanbeyan (Australia Day meet) it lost that much power I thought I could have gotten out and walked faster. I'd just filled up with fuel and was starting to have thoughts of bad fuel.
Got to the top of the hill and all was good, never experienced it again.
No engine Mods.

[TPC]

Mine always performs the same, have never noticed any big variations in performance.

I have blocked the EGR an 8mm hole drilled in the center of the blocking plate and I have a 3" Genie exhaust and a snorkel, but no other engine mods.

[vfamily]

Hodge mine has the same issue as your so I will be monitoring this thread closely some days I goes like a rocket other days its a complete slug just feels doughy and flat.
I have just fitted a 3" exhaust but that really has not made any difference, I don't have a EGT or Boost gauge fitted but do have a scan gauge which I have been using to monitor boost which I think is a bit low mine very rarely goes above 15-16.
When I get home in a 17 days I will be fitting up a EGT and Boost gauge.
Mine feels like it struggles to breath or something like that you get the sensation that something is holding it back, I am getting a snorkel fitted next week will be interesting to see if it makes any difference ( i doubt it but you never know)
2012 Auto with 40000km's now fitted with genie 3" legendex exhaust system

[vfamily]

I have also bought it up when getting serviced at nissan all they come back with is it doesn't bring up any fault codes

[4bye4]

Do these vehicles have a catalytic converter fitted? If so check this link.
http://www.aa1car.com/library/exhaust_backpressure.htm

[vfamily]

mine does it had the same issue with the factory cat/exhaust and issue also remains with high flow cat and 3" exhaust thanks for the link

[Rock Trol]

Mine performs consistently day in day out, regular trips that include hills and never had an issue except once.

Towing the van up the hill out of Queanbeyan (Australia Day meet) it lost that much power I thought I could have gotten out and walked faster. I'd just filled up with fuel and was starting to have thoughts of bad fuel.
Got to the top of the hill and all was good, never experienced it again.
No engine Mods.

How hard where you pushing the car? The CRD's have a knock sensor and if the car starts over fuelling and not burning the fuel correctly they reduce the fuel until the load goes off. They then reset to normal.

[jack]

How hard where you pushing the car? The CRD's have a knock sensor and if the car starts over fuelling and not burning the fuel correctly they reduce the fuel until the load goes off. They then reset to normal.

I did put the foot down but no harder than I've done other times on similar hills. Have towed the van up the Bulli Pass and up to Atherton with a heavier load on board and had no issues.
If it happens again I'll pull over and start again if possible.

[Hodge]

Thanks a lot for your replies folks. The more feedback the better.
Vfamily - very interesting if it is the same problem. Now I have a question for YOU as well as others, but mainly you since you think we have a common issue ... Sometimes, well most of the time when I turn the car off, I can hear a whirring sound, like a small electrical motor running and something is clicking making noises for about 2-4 seconds after I shut the car off. It is coming from the engine on the drivers side... I will record it tomorrow and attempt to show it here. I am only guessing that the EGR valve, butterfly valve or swirl valve is closing or opening or something along those lines as there is no other moving parts around there once engine is shut off.... I think anyway.

So Vfamily if you could check this and I will record it tomorrow and we'll see. I'm looking at the manuals so I can understand how the whole intake vs. EGR system works. Watch this space!

[vfamily]

No problem I will check mine next time I am home which unfortunately is not for another 16 days doing fifo at the moment, I cant say I have heard a noise after shut down but I haven't been listening for it either.
Also spoke to Nissan service dept again and if time permits I will leave the car with them for a few days next time I am home, they reckon they have a few more things they can try like recalibrating the fuel pump etc.


Thanks a lot for your replies folks. The more feedback the better.
Vfamily - very interesting if it is the same problem. Now I have a question for YOU as well as others, but mainly you since you think we have a common issue ... Sometimes, well most of the time when I turn the car off, I can hear a whirring sound, like a small electrical motor running and something is clicking making noises for about 2-4 seconds after I shut the car off. It is coming from the engine on the drivers side... I will record it tomorrow and attempt to show it here. I am only guessing that the EGR valve, butterfly valve or swirl valve is closing or opening or something along those lines as there is no other moving parts around there once engine is shut off.... I think anyway.

So Vfamily if you could check this and I will record it tomorrow and we'll see. I'm looking at the manuals so I can understand how the whole intake vs. EGR system works. Watch this space!

[Hodge]

Ok folks here is the video of the sound coming from firewall side of somewhere around intake area, when I turn the motor off... I've recorded and fused 2 different engine shutdown videos, both showing the same sound roughly ...
Video (sound) shows a clicking / whirring / whinning sound
once engine turns off
between 7.00 and 16.00 seconds and
between 30.00 and 36.00 seconds ...
Sounds like something is trying to open or close with a sound of a small electrical motor... I am not sure. I'm hoping this is my problem. Although I don't know how hard / expensive it is to replace the assembly.

So for those with a CRD does your car make this sound once shut down ????


https://www.youtube.com/watch?v=-3O-PUYgtj8&feature=youtu.be

[Hodge]

PS make sure you have the video in HD for clearer sound.

[vfamily]

I have the high pitch noise but don't recall the other one which sounds like a valve changing state, I will check in a few weeks when I get home, thanks for the clip great idea

[Hodge]

Thanks for the reply mate. Will be interesting to hear if others have the same noise or any part of it...

[mudski]

Eric we spoke a while back about this. I would try holding the swirl valve open. I cant remember how it works on the crd's but with the Di's its vacuum controlled in the throttle body just before the intake manifold. So in this case its a matter of removing the vac line as its normally open and the vacuum will shut it.
Maybe the swirl valve on yours is sticking on not working right. Dunno. The swirl valve on yours is in the actual manifold itself if my memory serves me correct.

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[Hodge]

Yeah thanks mate. I did talk to you about it... But I don't think the CRD has a swirl valve. This valve in the pictures circled in red is only there to promote a smooth engine shutdown. And it's a bitch to get to.
Stupid question, but does the throttle chamber (#3 in second photo) have an opening closing valve? I'm guessing it does ? If this is motorized, this could be my problem? I'm, not sure.

http://www.nissanpatrol.com.au/forums/attachment.php?attachmentid=59381&stc=1http://www.nissanpatrol.com.au/forums/attachment.php?attachmentid=59382&stc=1

[Hodge]

I stand corrected Mark! CRD indeed does have a Swirl valve and a eletric operated throttle, compared to the Di which has a vacuum one.

ZD30DDTi Intake Manifold
The Intake Manifold as shown right is mounted on the
RH side of the Cylinder Head.
An electrically operated Air Intake Control Valve is
utilised & the Swirl Valves have been incorporated inside
the intake manifold.
Electric Throttle Control Actuator;
On the previous ZD engine as well as the non DPF YD25
engine, the Air Intake Control valve was vacuum
controlled. Now on the new ZD30 CRD engine, the valve
has the same purpose as previous, however it is
electrically operated. Its operation is very much the same
as a ETC unit found on many petrol engines.
The Throttle valve is fully opened when the engine is
running. The valve is closed only to perform smooth
engine stop when the ignition switch is turned OFF. A
feedback sensor (Throttle Position Sensor – TPS) is also
installed to ensure the ECM can detect the throttle plates
position.
http://www.nissanpatrol.com.au/forums/attachment.php?attachmentid=59447&stc=1

(Vacuum operated) Swirl Valves;
The swirl control valve is installed inside the manifold
assembly. While idling and during low engine speed
operation, the swirl control valve closes, thus the velocity
of the air in the intake passage increases to produce a
swirl (rush of air to promote cleaner burning when the
fuel is injected into the air) into the combustion chamber.
Once the engine speed increases to a certain speed, the
valves open to allow more air to enter the engine.
Further information regarding the components shown
right can be found in section EM & EC of the Service
Manual.

http://www.nissanpatrol.com.au/forums/attachment.php?attachmentid=59448&stc=1

[Hodge]

Just lost a lot of skin attempting to get to the vaccum hose controlling the swirl valve. What an absolute c%^& to get to... In the end I failed. Impossible without ripping out the complete fuel / rail assembly out. Onwards and upwards.

[mudski]

Just pinch the vac hose with something to stop flow. Will do the same thing.... I have a brake line clamp here if you want to use that.

[Hodge]

Thanks mate thought about doing that that line seems stiff and didn't wanna damage it. Will give it another red hot go .

[Hodge]

Had a chat about cars today with our truck diesel mechanic at work, and I told him about my intermittent car mood swings and told him all the symptoms... He asked me whether it could be the clutch ??? Now he made me think about it ...
Every now and then, maybe once or twice every 2 weeks, when taking off in first, the moment the instant moment I start taking my foot off the clutch pedal, there is a reasonable click/clunk heard under my feet. Now I am not sure whether it's clutch related or 1st gear related. But right after that the car engages / takes off as per usual...

I know fark all about clutches... Is it possible that my clutch can engage normally, and then other times for a little bit it can engage enough to send power to the car but slip a little bit, so as to not transfer ALL the power from the engine to the gearbox/wheels ???

I have never had it slip in any gear, any speed, high and low range except that clunk/click I mentioned above.

If it was slipping or not properly engaging, I'd probably be smelling it burning or heating up or something?

Another item to check perhaps.

[vfamily]

my patrol is auto has the same random power loses

[Hodge]

my patrol is auto has the same random power loses

You know when I was talking to him about the clutch possibly being at fault, I thought of your same issues... But makes one think though.

[Rock Trol]

If you are getting a click/clack sound from the clutch it might be the flywheel (dual mass).
When you lose power does the engine feel OK but no speed or does the engine start to struggle?

[Hodge]

If you are getting a click/clack sound from the clutch it might be the flywheel (dual mass).
When you lose power does the engine feel OK but no speed or does the engine start to struggle?


I don't think engine ever struggles or hesitates... It's just hard to tell and explain. One set of lights, the car's response / accelerator is very sharp and responsive, takes of like a rocket, from take 1st gear to fifth. Few minutes later, the next set of lights, or sometimes longer...the accelerator is very spongy, car has power, but takes forever to get up to speed compared to moment ago when it was all good. And when this happens the boost maxes out and EGT's go higher than usual very quickly.

Once again, high EGTs means fuel is being pumped in, boost is created and held but power is not being transfered from there onwards... I just don't know.

[Rock Trol]

Boost is measured in the Intercooler so that must mean that the butterfly is open. There is nothing else between the intercooler and intake valves that I can think off. Is your egr blocked? Hi boost normally equates to low egt's. I wonder if its a sensor causing the problem so that the ECU is receiving the wrong information. Crank angle sensor for instance. If it sends wrong signal then timing is off. Do you get black smoke when you lose power?

[Hodge]

Boost is measured in the Intercooler so that must mean that the butterfly is open. There is nothing else between the intercooler and intake valves that I can think off. Is your egr blocked? Hi boost normally equates to low egt's. I wonder if its a sensor causing the problem so that the ECU is receiving the wrong information. Crank angle sensor for instance. If it sends wrong signal then timing is off. Do you get black smoke when you lose power?

Sensors could be a possibility. It's just, why is it good one moment, and not so good the next...
My car does not smoke one bit. I have had a few people drive behind me at various speeds from Melbourne to the high country, up hills, flat roads... Various types of rd. And I asked for them to look out for any smoke from my Patrol and they said there was absolutely none!

There is the butterfly/swirl valve in the intake, as well as the eletronic throttle valve between the IC and intake. Pic below. As the discussion with Mudski earlier in the thread, the swirl valve MAYBE sticking. * shrugs *

http://www.nissanpatrol.com.au/forums/attachment.php?attachmentid=59572&stc=1

[Hodge]

I also forgot to mention to you, that boost maxes out quicker than usual when it's in a bad mood... So normal driving I rarely go over 17-18. My wastegate is set to 20Psi. When the car is in a bad mood, it hits 20 fairly quick. Which is why the guy at JPC thinks that boost builds up quicker at intercooler, where the sensor is, but something is restricting it going further... Hence the though about the swirl or throttle valve maybe sticking?

His idea is to chuck a boost gauge in the inlet manifold and compare the PSI in there with the PSI at my usual sensor (intercooler).

[Rock Trol]

That makes sense then. It explains the lack of power and high boost. Sounds like a difficult part to get to though.

[Hodge]

That makes sense then. It explains the lack of power and high boost. Sounds like a difficult part to get to though.

The said parts are easy to work on. But you have the complete fuel system assembly right above it, preventing full access. The rail, filter, all fuel lines are right there and would have to be removed to get to it.

[kevin07]

mine always the same 2.75 ex steinbauer on 5 egr blocked smooth and consistent.

[vfamily]

Hi Hodge

I finally got home today, and can confirm that my patrol makes to same noise on shut down as your does
Hope this helps in some way

[bazzaboy]

My 2014 Titanium seems consistant, day in, day out. I do over 120 klms a day just getting to and from work. I sit on between 100 - 115 klph and drive it like I stole it. I personaly think that modern diesels should be worked hard so as not to "clog" them up. Mine now has 28k on it and since the 20k mark it seems to have "freed up" and you can feel the difference in the way it runs.

Bazza

[Clarkie]

Hi Hodge

I finally got home today, and can confirm that my patrol makes to same noise on shut down as your does
Hope this helps in some way

Yeah mine also makes the same shutdown sequence.

Mine has chip, exhaust and catch can and gets better with age. Hope you find your problem

[Hodge]

Thanks for the info folks. Patrol is now gone anyway, but me and a mechanic could not fault it in the last month or so, hence no fault, no problem find.
So frustrating finding incosistent faults. The new owner drove it for ages and found no difference.

[lagoonboy]

x3 Hodge.

Runs like a dream during winter however summer its terrible on hot days and fuel usage rockets. I will take that a bit further and say even in winter when Ive been driving for an hour or so, city or highway, and the temps in the engine bay warm up, it seems to drop a bit in power then too, however not as much as when the weather is hot.

Be interested to see the outcome mate

[lagoonboy]

Sorry I thought this post would back onto the other relevant posts on the first page, my bad