[jukecvt2012]

Hi there,

I'm having trouble with my Juke (please see build below) where I am finding two types of scenarios which I believe are related either to the clutch lockup, torque converter or slippage.

1) Upon accelerating from a dead stop the clutch lockup occasionally seems to disengage at around the 40-60kmh mark (25-37mph). This happens regardless whether the car is cold or warm. It happens with constant push on the throttle. When the clutch lockup disengages the following happens: *) RPM drops from 2K to 1K immediately and rises back to normal, there is hesitation in acceleration when the RPM drops. *) The brake assist seems to disengage and the car rolls when the clutch disengages. There is only one instance of this happening until I come to a deadstop and perform the next cycle (i.e. dead stop then accelerating again). There is no vibration in the vehicle

2) Under light accelerating 1.5K RPMs and around the 40kmh mark the RPM drops to just below 1K, i'm thinking 900. At this point the engine bay vibrates, hesitates in acceleration momentarily before the RPMs rise back to normal and I can accelerate smoothly. This happens regardless of whether the car is cold or warm. Constant push on the throttle is applied here aswell.

Both of these scenarios occur regardless if the car is in normal, sport or eco mode. However, I must say that is less noticeable in sport mode. I have tried different types of fuel without success either.

The reason I believe it is either the lockup or torque convertor is because what I see happens in CVTZ50 when my situation occurs.

There is no check engine light or codes on my tool

I believe my situation was occurring even prior to my transmission rebuild

Build:
2012 Juke 1.5 NA YF15
CVT transmission (has been rebuilt once at 55K kms (34K miles)
62K kms (38.5K miles)
HKS mushroom filter
Kakimoto muffler

Service:
Throttle body cleaned - actually removed from intake (last week). Relearn done aswell.
MAF sensor cleaned (last week)
Engine oil cleaned (3 months ago)

Please see my CVTZ50 data attached and also a snippet of what I am referring when I mention clutch lockup (this is not my snippet)

Please let me know if you need further information.

Thanks in advance

 

[pboglio]

I don't see much on the datalog. An rpm drop is not likely to be the transmission. It sounds like the MAF. I would datalog and see the actual vs. predicted airflow and see if they match, if not you have an intake leak or MAF issue or the computer is getting the wrong idea about airflow and having trouble with requested torque. The transmission would throw codes if the transmission had issues. Tthe automatic clutch solenoid is not dropping out on the datalog that I can tell other than at idle or low rpms/low speed which is normal, bu it don't doubt it might do something bizarre with engine issues. It's possible the engine issues are affecting the transmission, but it doesn't seem to be the other way around.

So, and engine datalog might help to understand more about the issue.

 

[jukecvt2012]

I don't see much on the datalog. An rpm drop is not likely to be the transmission. It sounds like the MAF. I would datalog and see the actual vs. predicted airflow and see if they match, if not you have an intake leak or MAF issue or the computer is getting the wrong idea about airflow and having trouble with requested torque. The transmission would throw codes if the transmission had issues. Tthe automatic clutch solenoid is not dropping out on the datalog that I can tell other than at idle or low rpms/low speed which is normal, bu it don't doubt it might do something bizarre with engine issues. It's possible the engine issues are affecting the transmission, but it doesn't seem to be the other way around.

So, and engine datalog might help to understand more about the issue.

Thanks for your response. I've tried two different MAF sensors (1 from Qashqai and 1 from Tiida). The problem still exists.

I've also had a visual check of cracks in pipes in relation to vacuum leaks, however I couldn't find anything.

Im not too familiar with all of cvtz50s functions. Where would I find the data required for actual vs predicted airflow?

 

[pboglio]

You need to build an intake pressure tester. A silicon hose, hose clamps, plumbing fitting, and an air line quick adapter can be made for like $30. You will find more leaks than you can imagine. What you describe is almost similar to when I got water in the coil on plugs after a pressure wash.
There are obd2 dataloggers that might provide that data. I use ECUTek running logger and the MAF reading and MAF calculation usually are close.

The Hotwire maf usually have problems when they get water on them. Check your turbo intake pipe and make sure it’s not full of oil. This can blow back onto the MAF and cause issues.

 

[Macgyver]

The only 1.5 is a diesel.

There is a 1.2 AND a 1.6 that are NA

 

[jukecvt2012]

You need to build an intake pressure tester. A silicon hose, hose clamps, plumbing fitting, and an air line quick adapter can be made for like $30. You will find more leaks than you can imagine. What you describe is almost similar to when I got water in the coil on plugs after a pressure wash.
There are obd2 dataloggers that might provide that data. I use ECUTek running logger and the MAF reading and MAF calculation usually are close.

The Hotwire maf usually have problems when they get water on them. Check your turbo intake pipe and make sure it’s not full of oil. This can blow back onto the MAF and cause issues.

Im not sure how this differs as you mentioned as mine is the 1.5 NA (non turbo) and its a japanese model so it is indeed a 1.5 petrol. I might get the Nissan Dealer to have a look into it.

On the other hand just throwing out ideas do you think its related to the torque convertor or electronics such as the TCM/ECM. Because I can replicate the problem 100% on demand and it happens exactly at the same point.

 

[pboglio]

The torque converter un-locking is a consequence of the rpms dropping to idle, that's it's main function. Why the car is dropping into idle at light cruise is the problem.
The car is fly-by-wire so it's seeing something it doesn't like. If I remember correctly there is an accelerator peddle sensor on the Juke that basically tells the car what the throttle is doing in relation to the throttle plate. It's possible, it thinks at low throttle angles that the accelerator is actually not being pressed, thus it drops into idle.

This is how stability control works, the ECM must have access to the throttle and do what it wants when it sees something it doesn't like. This is called "torque demand", as in the car reacts to what you command and attempts to achieve the appropriate "torque" or engine output any way it can. This is kind of a good thing because the computer is figuring out the throttle plate angle, ignition timing, fuel A/F, etc. to give you what you want. It sounds like it doesn't know that 1500 rpm isn't actually idle, perhaps the accelerator switch/sensor is saying the accelerator peddle is OFF basically. That 1500 rpm @ 40 mph is extremely light throttle but much higher flow than 900 rpm idle. When the engine stumbles and recovers makes sense. Basically, to achieve 900 rpms stability the engine would basically not be under load. What I'm saying here is Nissan knows the exact amount of engine frictional drag and has dialed the throttle plate angle accordingly to achieve idle stability. How that could be maintained while cruising is impossible. I'm saying to achieve 900 rpms while cruising would require a different throttle angle position than if it was stopped. This is kind of confusing to the ECM, thus I could see it stumbling.

Again, you can easily check Throttle position % vs. Accelerator position %, etc. on the logger and if these don't correlate, something is seriously wrong. I'm not saying they are always identical but if the Accelerator % goes to ZERO while clearly you are still pushing it, then it's a sensor problem.

Also, the HKS mushroom filters are absolute garbage. It will drastically wear out the engine and the foam oil will foul any hot wire MAF sensor. I'd highly recommend going back to stock air filtration as open elements can be highly affected by radiator fan wash and that sort of thing and the engine heat soak can really screw with the engine ignition timing.

 

[Macgyver]

it is not a 1.5 They never made a NA 1.5.

Start simple. Its prolly a fluid problem or worn valve body. Change the fluid. Then if that doesn't work. Change the brand of fluid.

 

[pboglio]

Here: Nissan Juke - Wikipedia

It's clearly a 1.6 petrol w/CVT.

OK, I've reviewed this log again. What I find very odd is that the Primary Pulley & Engine rpm don't actually match.........ever. My datalogs when the converter is supposedly locked up, the (2) rpms are damned near close to identical.

This is going to be tough to explain: The gear ratio is a good value to look at. Secondary pulley rpms almost all the times when the converter is locked-up matches the Engine rpms @ 1:1 gear/pulley ratio, this is to be expected as this means no slipping. Yet Primary Pulley rpms are about 1/2 those. That is NOT correct. At 1:1 ratio Primary/Secondary/Engine rpms should all be identical.....yet they are not. At idle the torque converter will slip normally and the Primary RPM will basically be zero while engine rpms at 700-900 rpms. Your datalog shows this similar pattern @ Idle but NOT at cruise.

I think the Primary speed sensor isn't reporting correctly the true rpms. In fact, on your car it's usually 30-40% lower than engine rpms. So at 1600 rpms, the TCM sees the transmission at only 1000 rpms and maybe it thinks you are supposed to be idling, and reports this back to the ECM and all funkyness begins.

There is a shim washer that MUST be used at the correct thickness from the Factory for the Primary Sensor. If this is left out during an install it will product some funky results. Since you recently had a CVT rebuild, I'm thinking they screwed this up. This is notoriously easy to do, and easy to fix/check. If the washer it completely missing, you can try buying the shim washers and trial/error the results to nail it. The datalogs should have the Primary Pulley and Engine rpm matching closely if the sensor is working correctly as a check.

Anyway, that's my analysis. So you are kinda right, it is something with the CVT but it's not throwing a code yet the datalogs clearly show the sensor isn't reporting correctly. This sensor can be accessed from the top of the transmission I think, not too hard. I'd try and take it off and look for the shim adjustment washer, no washer means no good.

 

[jukecvt2012]

Here: Nissan Juke - Wikipedia

It's clearly a 1.6 petrol w/CVT.

OK, I've reviewed this log again. What I find very odd is that the Primary Pulley & Engine rpm don't actually match.........ever. My datalogs when the converter is supposedly locked up, the (2) rpms are damned near close to identical.

This is going to be tough to explain: The gear ratio is a good value to look at. Secondary pulley rpms almost all the times when the converter is locked-up matches the Engine rpms @ 1:1 gear/pulley ratio, this is to be expected as this means no slipping. Yet Primary Pulley rpms are about 1/2 those. That is NOT correct. At 1:1 ratio Primary/Secondary/Engine rpms should all be identical.....yet they are not. At idle the torque converter will slip normally and the Primary RPM will basically be zero while engine rpms at 700-900 rpms. Your datalog shows this similar pattern @ Idle but NOT at cruise.

I think the Primary speed sensor isn't reporting correctly the true rpms. In fact, on your car it's usually 30-40% lower than engine rpms. So at 1600 rpms, the TCM sees the transmission at only 1000 rpms and maybe it thinks you are supposed to be idling, and reports this back to the ECM and all funkyness begins.

There is a shim washer that MUST be used at the correct thickness from the Factory for the Primary Sensor. If this is left out during an install it will product some funky results. Since you recently had a CVT rebuild, I'm thinking they screwed this up. This is notoriously easy to do, and easy to fix/check. If the washer it completely missing, you can try buying the shim washers and trial/error the results to nail it. The datalogs should have the Primary Pulley and Engine rpm matching closely if the sensor is working correctly as a check.

Anyway, that's my analysis. So you are kinda right, it is something with the CVT but it's not throwing a code yet the datalogs clearly show the sensor isn't reporting correctly. This sensor can be accessed from the top of the transmission I think, not too hard. I'd try and take it off and look for the shim adjustment washer, no washer means no good.

Thanks I will look into this.

I hate to argue but my model is 1.5 petrol. This model is available in NZ. Nissan Juke 15rx Premium White Package Specs, Dimensions and Photos | CAR FROM JAPAN

 

[pboglio]

Yeah, I'm not familiar with the various Jukes oversees. So I believe you and really I don't think it's super important to your problem, but thanks for clarifying.

Question though, why would a car need a CVT rebuild at 34k miles? What happened to the car?

 

[Schmiddles]

Sorry to intrude on this topic, but I'm also having exactly the same issue as Jukecvt2012. I have the same engine too, the 1.5 HR15DE engine. I'll be watching this for any updates as i'm struggling to fine a cure for the problem. I've also just had my CVT rebuilt too at only 47k miles as it was slipping really badly, upon inspection, the forward clutches were burnt out, a spool in the valve chest was stuck and the belt was a little worn. I was hoping after the rebuild the missing/rpm issue would have gone but it still persists.

 

[jukecvt2012]

Yeah, I'm not familiar with the various Jukes oversees. So I believe you and really I don't think it's super important to your problem, but thanks for clarifying.

Question though, why would a car need a CVT rebuild at 34k miles? What happened to the car?

Im not sure how the car was driven when in Japan.I'm the 2nd owner in my country.

I'm trying to get Nissan to look into it buts its busy after the new year.

I've uploaded two photos on the rebuild and Nissan's comments

 

[jukecvt2012]

Sorry to intrude on this topic, but I'm also having exactly the same issue as Jukecvt2012. I have the same engine too, the 1.5 HR15DE engine. I'll be watching this for any updates as i'm struggling to fine a cure for the problem. I've also just had my CVT rebuilt too at only 47k miles as it was slipping really badly, upon inspection, the forward clutches were burnt out, a spool in the valve chest was stuck and the belt was a little worn. I was hoping after the rebuild the missing/rpm issue would have gone but it still persists.

Hey, do you have a video of your problem. Really interested to see it

 

[pboglio]

OK, those invoices are really good.

They replace the main bearings, pump relief valve, full rebuild kit including clutches/seals/setc.
The converter looks like it's a reman unit which is good I suppose, that's a good call to replace it.
What I don't see is the pushbelt being replaced. The valvebody also hasn't been touched.

This is why the rebuilds I don't recommend, you have to replace almost everything. The valvebody
they also could have replaced with a rebuilt unit at the least and IMHO there are many problems
that are solved if that is replaced.

 

[jukecvt2012]

OK, those invoices are really good.

They replace the main bearings, pump relief valve, full rebuild kit including clutches/seals/setc.
The converter looks like it's a reman unit which is good I suppose, that's a good call to replace it.
What I don't see is the pushbelt being replaced. The valvebody also hasn't been touched.

This is why the rebuilds I don't recommend, you have to replace almost everything. The valvebody
they also could have replaced with a rebuilt unit at the least and IMHO there are many problems
that are solved if that is replaced.

Last week I went to Nissan and they did a relearn of many variables as they found a lot of the parameters were out of range as per the attached image. I performed alot of the reset of variables on my own but the one I couldn't do was the O2 sensor as I believe they need consult for this.

They told me to drive the car for a week and provide them with feedback which I have done today.

They also believe it could be a faulty ECU which is causing my symptoms. They have dumped the readings and have provided this to Japan for analysis for which I am still waiting to hear back on.

Overall, the car still experiences my symptoms but it is less evident now. I am also driving with the OEM stock air box now. I am hoping it is indeed the ECU as they have potentially nailed it down to this.

 

[pboglio]

Good feedback. Keep us posted.

 

[Macgyver]

What are the remaining issues now ?