New information today. In the last post I made, I did a poor job explaining what actually happened as there was some misinformation going around but here is a quick blow by of what happened

New VQ35DE 65k Motor gets swapped in, about 2 months in the car starts making a knock noise which is then pointed towards the Catalytic Converter, we then hollowed the Cats then noticed the car ran very sluggishly. The car started driving more sluggish and then a code threw a few hours later. P0021 P0011, I changed the solenoids and nothing happened and the codes still threw, I then took it to a mechanic and did some findings. Firstly he dropped the pan, no orange guides or pieces and no metal shavings, Secondly he looked through a service port or he took the two timing caps off (No Play and timing was dead on, I also misheard from him that he changed the chain to which he didn't), Thirdly he changed the solenoids as he said it read low voltage and codes didn't throw for 3 days until it came back which started as P1135 and P0021 then later changed into the Usual P0021 and P0011. The car now won't even start or run and even if it could start, it wouldn't break 10 mph literally.

Later, we went to pick-n-pull and took a used timing chain, sprockets, guides, tensioner then went for a new Crankshaft Position Sensor and another new one from O'Reillys. We were about to start the job until we started trouble shooting some things, what we did notice is the Crankshaft Position Sensor (Both Old, Used, and New) caused the car to not run as we switched it out sometimes and the car would idle at literally 200 rpm then sometimes just wouldn't start at all but a interesting find is that without the sensor, the car starts up strong and it has lots of its power back like it is out of its limp mode but with a few things that I noticed, the car would take 5 seconds to crank and start, the rpm when driving would stutter when looking at the tachometer (It would wobble up and down a bit when going higher in rpm), VDC and SLIP light stays on, at around 2k or 3k it's like I hear very quiet pop noise from the car once I accelerate past those points, the car would kind of tap on the gas on it's own when in D and letting it coast from a stop but only does this when letting the rpm rise on its own, Idle is a bit on the high side ranging from 1k to 800 rpm.

Something I did notice a while back though if this helps at all, the tranny feels as if it slips sometimes but only when I accelerate at a certain rpm but this was while the car had its power and within its new engine time line, I'd say a month before these codes, there's a knocking noise coming from the tranny and it's a "Bearing" that is going out as my friend would say

It's like the codes aren't even there anymore as I drove a few days without this sensor and I never got P0021 P0011 back, I did see another forum state that it's the flywheel or flex plate either being broken or worn out and that fixed their problem, would anyone have any idea on how to fix this as well as if the P0021 or P0011 might come back or not?

 

Ok just to clarify, you're saying the engine will start up and run WITHOUT the crank sensor plugged in?? And to verify we're talking about the correct sensor the CKP is the one at the bottom of the engine sort of on the driver/left side of the engine yes.

It should not be possible for the engine to run without the crank sensor plugged in.

It's well known that these engines do NOT work well with any aftermarket sensors, you can use only Genuine Nissan OEM sensors or Hitachi because they were the manufacturer of the OEM sensors. All those hard start, stutter, pop, idle, etc issues could very well be the CKP sensor.

The flywheel/flex plate issues usually aren't because of worn/damaged components but rather from people not installing them correctly. There is an alignment dowel on the crankshaft that needs to line up with the notch in the flywheel/flex plate. It's possible to install it in any configuration but the engine will ONLY work properly if it's in the proper alignment.

If the engine ever did work properly then it's probably not because the flywheel/flex plate got clocked wrong, you know from the moment you finally get the engine to turn on that something is seriously wrong.

 

Thank you, that eases some tension a bit, I've read on some forums that this person had similar issues and the car would not start and if it did, it would run like **** then ever since he took out the sensor, it would take a few seconds for the engine to start but when it would, it would start up strong with power but with a few drawbacks. This all started happening a bit after the hollowed cats, still not sure but not ever once in my time of owning this car did I get the code P0335 then just taking out the sensor fixes this problem. We tried a junkyard pulled sensor which didn't work as it was random and still would idle and run like ****, we tried one from Oreilleys and that didn't work, we tried the one I originally had but its obvious that didn't work. I'm just dumbfounded on how this sensor could be the problem of being in the worst limp mode ever and not throw a code about it...

 

Did more research, some guy mentioned that if the Tachometer (Assuming RPM's) doesn't move while cranking the engine, it should well be the Crank sensor, that being said, I already returned the sensor from Oreilleys so I only had the old Stock one to work with, I got the car up on the jack and plugged the sensor in and started cranking and noticed that the RPM's don't move at all while the car is cranking so hopefully the new one from Z1 will work, a little note I forgot to mention is that the car sounds like its about to start but does not want to without the sensor in. If that contributes anything at all. I will try to update this thread as much as I can and hopefully I can get some help along the way...

 

A little update, while driving, somewhere in between 1-2k rpm if held there, the car sounds and feels as if it’s shaking/stuttering and jumps a little if held there but past that, it smooths out except the rpm needle that still shakes along the way…

OEM sensor comes in soon today, hopefully this resolves all of that…

 

I mean it SOUNDS like it's a CKP but you may have a damaged wiring/harness that's causing issues. inspect the condition of those next time you're down at the harness.

The engine takes the signal from the CKP to determine exactly when to deliver spark/fuel, the signal can definitely be bad at only certain rpm points. Basically how the hall effect sensors work is the moving part (flywheel/flex plate) has a pickup on it that sweeps past the sensor, every time it does this it creates a little voltage pulse that is read by the ECM. It's a VERY VERY precise reading and if the sensor is damaged at all (usually starts to develop tiny cracks on the plastic that lets moisture or oil into the coil winding) then it sends a bad signal back to the ECM.

P0335 usually means the ECM cannot read the signal AT ALL but if the sensor is damaged and just not sending the correct signal you might not get the code.

A tachometer that doesn't move is pretty indicative of no signal, the CKP is what the tach is based on. No CKP signal and the ECM will not deliver fuel/spark at all.

It's very common for aftermarket sensors to not function properly, they might send a signal but it's the wrong signal, use only Genuine Nissan or Hitachi (Hitachi is the OEM manufacturer for that part).

 

New note, Engine started normally but right when it started, it died out then went back to its “Not starting with sensor in” mode, I cleared codes and still nothing. I did notice though that there is a slight groove going down the front. If anyone knows if driving without this sensor is also dangerous, pls let me know as I need money to fix this problem.

also here is an picture

 

It’s on the bottom side, I noticed this on the new sensor after I took it out for the inspect

 

I think you should get the car up on jackstands and inspect behind the flywheel ring gear for damage. You're going to need to either rotate the engine from the crank pulley or by bumping the starter. If you do it by bumping the starter just be sure you are on FOUR jackstands so the drive wheels aren't touching, pull the fuel pump relay and then start the engine and let it stall out from no fuel. This way you can get quick controlled bursts on the starter.

Fully inspect the entire diameter of the pickup behind flywheel ring gear, there is a dummy plate on the opposite side of the engine from where the starter is mounted (different vehicles used the starter in the other side of the motor, same engine block) you can remove the 2 bolts on that blockoff plate and have good access to inspect the flywheel with an inspection mirror to look behind the ring gear teeth. Something is damaged on it though which is eating your sensor, it should NOT have any kind of wear/abrasion on it like that.

 

thank you for all the help Cleric, but it is already too late now, just yesterday, I was driving down my usual road then the car shifted then for some reason slipped very very bad. As in slip, I mean the transmission felt completely like it wasn’t connected to the engine and felt like a grinding noise as the car was in “D” and the car would rev freely. It was then pushed into a parking lot and noticed when trying to start the car, the flywheel would move but the engine would crank then hesitate then crank again, the area where the sensor would be would make a grinding noise… in hindsight, this was totally my fault, that sensor was there for a reason and I totally mistook it as a sensor problem even though it was telling me that somehow, the flywheel damaged, not sure how but the only thing I can think of is the new engine swap so that might be why.

Again, thank you cleric for helping with the technical stuff and I’ll be back soon to give an update. Am trying to find a AT flywheel and hopefully that fixes it and I pray to god I didn’t just Blow another Engine…

 

The Noise it makes and view of front of engine and CKP sensor area

 

You lost a bolt/s on the flexplate that holds it to the crankshaft, I can see lateral play at that camera angle looking through the CKP sensor area.

Hopefully it didn't damage the torque converter or the tranny input shaft but I suppose you'll find that out when taking it apart.

When the engine went in last time did you torque the flexplate bolts? They don't normally get any loctite but they do need to be torqued down to 65 ft/lbs which can be tricky without a ring gear holder.

 

Ok, now there’s was a lot of stuff I have to cover, we did hella stuff and got the car running and drives fine now with all power back and the likes

We dropped the tranny and you were right, I lost a bolt on the torque converter, I was so eager in taking it off and when we actually did, the flexplate was done, like metal got snapped and the flywheel wasn’t working anymore, I’ll be posting pictures to show you what I mean. This was one hell of a project, I never went this deep into a car before. The flexplate journey at the junkyard was super hard to get, we worked 2-3 hours on one g35 then went through the service port just under the transmission to take off the bolts to the torque converter but the engine was Seized like it couldn’t move from the crankshaft bolt (Probably because the timing chain was broken of on one of the sides) so we had to bite the bullet and go to another G and do 2-3 hours on that one again and really exhausted

a very personal thank you to cleric, thanks for sticking with me on this thread during my problems. Also, we paid a shop to do the swap as they sell warranty JDM engines, but this all decided to happen after warranty did end. Torquing the torque converter with the torque wrench was the most scariest thing ever because we tried to torque wrenches, and if they’re up against something in a tight space, it’s not gonna Click at 65 pounds for Whatever reason, we only got it to click at 55 pounds but the click was super hard to notice.

Here’s a few things that we noticed after the engine swap. A few bolts that hold the transmission were missing (those were super hard to get but we got them), we noticed a piece of the BLOCK was missing (Right above the starter). Not sure if they torqued down the bolts but one of them was Missing out of the 4. Another thing I noticed, the dipstick was SUPER HARD to align (Have fun) and there is a vacuum line that’s super hard to get as well (Have fun pt2).

 

Flex plate to crankshaft is 65 ft/lbs, torque converter to flex plate is only 38 ft/lbs. All the big bellhousing bolts are 55 ft/lbs, the smaller ones (not including the ones for the starter or the starter dummy plate on the other side of the engine) are 41 ft/lbs.

Did you remove the catalytic converters? It shouldn't be that difficult to reach all those bellhousing bolts, I have fairly large arms and I can just reach around from under the transmission to put the top bolts in with my hands, then use about 36" worth of extensions to torque them. Removal is the same, use a bunch of extensions with a wobble to access them.

However I've had transmissions out of various G's several dozen times so it's all pretty routine for me now. I suspect you had the catalytic converters still in place because that would make the removal MUCH more difficult.

 

Take a picture of this missing part of the block too, I'm curious to see what's broken.