P0340
 

Hi all,

Just going to dump my problems here...

Driving home the other day, everything seems fine until the freeway onramp when I lose all power. It feels like the fuel starvation problem that I've experienced before, and I am low on fuel.. so I coast off the freeway, and eventually it gets some power back, but it's extremely jerky and definitely not a fuel starvation problem now.

I limp back to a parking lot. The idle is not smooth and bouncing between 800-1400, and it won't rev past 3.5k at all. When I tested revving it, TCS and slip lights also come on. I turn the engine off, try to turn it back on, it will crank but not fire.

Eventually I get a code reader working and see P0300 and P0340 - Camshaft position sensor error. Check the forums and see a few posts that mention unplugging the sensors might work. I clear the DTCs and try it:

Both sensors plugged in - won't start

Bank 2 unplugged - won't start

Bank 1 unplugged - will start, but cranks for much longer than normal, and is in limp mode and won't rev past 3.5k, but the idle is smooth, and everything feels fine otherwise! This has been reproducible every time.

I swapped the left and right sensors, both looked clean and the problem is still exactly the same, and not P0345, and still runs with only bank 2 plugged in, so I think both of the sensors themselves are working.

I probed all connections with a multimeter at both harnesses for OC, SC, and the signal, at the sensors themselves, and in the ECM harness and everything looks fine, and the left & right banks match, giving more evidence that it's not a sensor or electrical problem. I don't have a scope, but the signals are 5V when off and jump around near 4.5V when the engine is running, which is what you'd expect from working sensors.

I feel like I've eliminated any electrical problems, and could it really be a timing problem since the engine runs fine and smooth up to 3.5k in limp mode? But will keep looking.. I've ordered a scope to check the actual signals, and will try to remove the timing cover to inspect the camshaft gears and timing chain this weekend. Most of the other threads I saw didn't post resolutions. I'm hoping I can fix this myself and not have to take it to a dealer :P

Car is tuned with JWT intakes, Nismo exhaust, oil cooler, 60k miles.

Other threads:

http://www.the370z.com/engine-drivet...t-skidpad.html
http://www.the370z.com/engine-drivet...ode-p0340.html
http://www.the370z.com/nissan-370z-w...ont-start.html
http://www.the370z.com/nissan-370z-g...-ak370z-4.html
http://www.the370z.com/nissan-370z-w...-z-issues.html
http://www.the370z.com/nissan-370z-w...ont-start.html

When a problem doesn't move side to side, then the problem is usually wire/ECM related. Try removing the negative terminal from the battery, step on the brake pedal for 10 to 15 seconds (I don't remember exactly, there is a thread somewhere) to clear memory, then reattach cable. Try restarting the car and see what happens with both sensors plugged in. I doubt you have a timing chain issue, the car wouldn't run at all if it jumped time. If you have access to a good scanner (snap-on, MAC or Consult), that might help. GL.

The ECU seems to have an issue with bank 1 and may see it off timing for some reason and wont let you start to protect motor.
But when bank 1 signal is completely missing it uses bank 2 to work out timing for bank1 (only an approx.)and runs in limp mode. Which is why it cranks for longer.
You may have an issue with the variable valve timing on bank 1 or even jumped a tooth on the timing chain. Or ECU/wiring issues.
Could be few others things as well.
Your best to take car to an auto electrician

Thanks guys! I will double check all the wiring tomorrow when I get a scope, but so far everything still seems OK and the problem repeats even after resetting everything.

I discovered last night that the car was super low on oil.. it took almost 2 quarts before getting back up to normal :eek: and was pretty dirty. I did an oil change, but the problem persists. The low oil makes me think it could be an actual VVT problem like a gallery not getting enough oil pressure or tensioner getting clogged or something like the other threads mentioned. I'm trying to think of ways to verify the VVT before committing to tearing it all apart.

I think I found something interesting.

I checked all the signals with a scope and they all look OK individually:

Attachment 139823

bank 1 at sensor
Attachment 139813

bank 2 at sensor
Attachment 139814

bank 1 at ECU
Attachment 139816

bank 2 at ECU
Attachment 139817

Attachment 139824

crankshaft at ECU
Attachment 139818

And then I noticed this drawing in the manual and decided to test both channels:

Attachment 139825
Attachment 139819
Attachment 139820
Attachment 139821
Attachment 139822

It looks like bank2 is advanced about 2ms relative to bank1, if they're supposed to be lined up like the manual shows. this would be about 5 degrees.

I also tested phase vs crank, but these did not vary at all with RPM. maybe IVT doesn't kick in before 3500, or the ecu disables it entirely in limp mode.

I'm not really sure the 5 degree out of phase is an error or not without knowing exactly what the gears look like, but this timing could be off.

Show us pic of crank sensor vs cam phase bank1 at idle.

Sorry didn’t get a pic, but bank1 started about 4 notches into the 10 notch pattern in the crank, and bank2 was 3 notches in. i’m not sure where the zero point should be or what the expected timing at idle is. Will get a pic tomorrow.

Like you were saying. Both banks should be the same, just shifted 360 degrees.

Can you see the timing chain when the cam sensors are removed. I think there's a colored chain line that lines up with mark in the cam pulley.

Anyway first verify chain timing if off and why before opening engine up. Could also be a stretched chain due to high mileage. This would explain the variation in timing between banks 1 and 2.

How many miles on this car and how often is oil changed?

I think car will also run with both cam sensors unplugged. Try it.

And do remember this engine is an interference one so if it is jumping teeth due to loose chain you could damage engine beyond repair.

https://www.youtube.com/watch?v=GnW2NclDbi0

And

http://www.the370z.com/engine-drivet...ing-chain.html

Thanks for the links. The car won't fire with both unplugged even after clearing and resetting everything.

These are vs bank2 but shows the phase offset

Attachment 139845

Attachment 139846

I borrowed a friend's working G37 for a few minutes and got these traces of camshaft bank 1 vs bank 2

Attachment 139850

Attachment 139851

I think this seems to confirm that my timing is in fact off somehow, so I'll have to open it up.

Yep, seem to be off by a lot. Next is to work out why?

Best to open up and see for yourself. Or get a quote to fix.

Remember to replace oil gallery gasket as this was an issue with the 08/09 models.
And something about the screws also going loose. Find out how to replace properly if you are going to replace.

And turn engine over 4 times manually and rechecking timing before closing it up.
You may need to replace chain guides a well if they are worn.

How many miles on car? Water pump replacement might be a good idea.

Very cool diagnostic you ran there. There are threads here on replacing the oil gallery gaskets. I did it myself a year ago, happy to answer any questions.

You can get a gasket kit from ConceptZPerformance. And if you have $$ laying around, might be worth it to figure out what else you'd like done "while you're in there." I ended up relooming and tucking all the bay wires, replacing the belt, etc. Maybe an upgraded oil pump?...

Sent from my SM-G955U using Tapatalk

61K miles.

I've ordered the full timing chain rebuild including crank sprocket, gaskets, the new metal gallery gaskets, screws, and water pump. Those oil pumps are too expensive for me!

Have fun cleaning the grey RTV silicone off.

There is also the acc. Drive belt.

Be careful no to damage mating surfaces when removing cover.
Read FSM on how to remove timing cover without breaking stuff.

If you dont have some pry bars definitely invest in some. And a breaker bar / 4 foot length of pipe so you can cheater bar the crank pulley bolt.

Also depending on whose kit you bought, some non-hardened hex drivers. Hardened ones will strip the replacement hex fasteners.

Be sure to label every bolt and part... bc you will forget what went where by the end.

Quadruple check the chain positioning and secure the f out of it at all times. The absolute last thing you want to do is take it all apart again...

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:iagree:

It's raining this weekend, (and the parts still aren't delivered), so this will be postponed until I get back from vacation in January!

This has been by far the biggest job I've done. I've been working slowly over the last two weekends and now have everything removed and am ready for replacements.

There's a few tricky bits I struggled with before buying special tools. Here's my notes, hopefully they're helpful to someone:

Getting the crankshaft pulley bolt off was the hardest. Put the car in 6th gear, make sure the parking brake is tight, and get a BIG breaker bar. my 24" 1/2 drive breaker bar was bending... so I ended up buying a 40" 3/4 drive bar and socket, and that did it. Make sure you don't pull the car off the jack stands..
http://www.the370z.com/engine-drivet...olt-stuck.html

Removing the power steering bracket, there's not much clearance and you may need a *shallow* 14mm socket and/or a universal joint.

Removing the AC compressor, the far bolt also is also awkward and you may need some short extensions.

Removing the oil pan seemed impossible without the right tools, but once I got a strong putty knife (one you can hammer on) and the nissan recommended "oil pan separator tool" it was easy.
http://www.the370z.com/diy-section-d...an-spacer.html
https://www.youtube.com/watch?v=5735ycX1JhE
https://www.amazon.com/gp/product/B07NXVDP9X
https://www.amazon.com/gp/product/B00LCPOPGC

Removing the front timing cover seal took a while even with the right tools. Only the drivers side pry notch worked at all, and there's not much room on the sides to get a tool in to cut the seal. I didn't find any tricks here, just takes some time.

Everything would probably be easier if you can just remove the whole front bumper, but to do this you need to disconnect the AC refrigerant lines. This requires a special tool and the fluid would all boil off and is pretty bad. You could get an HVAC specialist to evacuate the system for you, but I didn't do this and just worked around the front bumper. You can undo the radiator assembly bolts and pull it a few inches out without disconnecting the lines, and this is sometimes enough to get a power tool onto the front of the engine.

Also regarding the complaints I've seen about the phillips head screws on the oil gallery covers torquing out - I tried a pozidrive #2 bit and it was much more stable than the philips bit. (I also bought the CZP hex replacement screws)

Some of the wiring harness zip tie/clips seem to be impossible to remove properly, so I just cut them and will replace them (still looking for the part number)

So, after taking everything apart, I have still not conclusively found a root cause of my problem. The timing marks all lined up, nothing looked broken, the oil gallery gaskets are all intact, nothing looked too dirty or gunked up, etc. Before I replace everything and put it back together and hope that it just works, what are the things I should check for?


However.. I just found these threads on G37:
https://www.myg37.com/forums/engine-...m-phasers.html
http://www.jimwolftechnology.com/wol...derslipped.pdf
https://www.myg37.com/forums/engine-...g-weird-2.html

Could this be my issue?

These are my phasers:
Attachment 140308
Attachment 140309
Attachment 140310
Attachment 140311


Comparing to the internet..
http://www.the370z.com/attachment.ph...1&d=1578982040

This is just comparing the bolt head, which could have no relation to the actual timing marks.. but it seems consistent. Could this be my problem? Has anyone verified this before?

Man... massive props for doing this without removing the bumper. For the pulley, I had my sister get under the car and pin the driveshaft with a lug nut wrench while I used a 1/2 breaker bar with a 4 foot pipe slipped over the handle. Dented part of the underbody w the wrench head but w/e.

I've no experience with the phasers but based on your pics that could be the issue.

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Found another related thread about the phaser encoder slipping: http://www.the370z.com/engine-drivet...oat-rodeo.html

Hi Knio,
From what I know these phasers they have a heavy return spring which sets phase to zero when there is no oil pressure. Can you move the 2 parts of the phaser back and fourth easily on the original one? Compare it to new one. It maybe stuck in one position.
Why this has happen is another question. Maybe related to low oil level.
Did you also compare length of the old timing chain vs new one?
Also, there are 2 solenoid valve on the front cover. Check these are working and not stuck open.

I can't move the phasers by hand. I think there's also a locking pin at zero that engages with no oil pressure. See this youtube: https://youtu.be/o61LjDqHzoQ

But, before I disassembled this, I manually gave power to both the solenoids while the engine was idling, and I confirmed that they both work, and the phasers do actually advance the timing. So the solenoids and hydraulics did appear to be working.

I don't see how the pressed in timing ring can move?

Maybe just a defect in the design or grade of metal used.
A least the new ones seemed to have a revised part number.

Yeah it seems weird to me too... but it matches my symptoms exactly, and ive looked at every picture of this part I can find on the internet now and seems like it has lol.

Maybe the whole sprocket gets too hot (because of the low oil), and expands enough that the pressed in inner ring gets loose, and then it just vibrates a bit?

You could of with some luck reset timing plate and tig welded without removing complete timing cover. Just the 2 smaller covers.

Hence why I was saying to work out what the cause of issue is before removing cover.

Anyway doesn't matter as its not guaranteed to work.

Did you notice high oil temps when you came off the highway?

And you year model is susceptible to oil burnt so you need to keep adding oil.
You should be using 10w40 or 5w40 from now on.

I don't think the different bolt heads has anything to do with it. The places you have circled in red show some deformation of the timing trigger. The eBay one has rub marks on the face of the one set of triggers, yours looks like one of the triggers is deformed slightly, as compared to the 'good' JWT one. You might see if there is a measurement for the gap in the triggers in the FSM (it might be a +/- .001 or so), then measure yours. My uncalibrated eyeball says that yours are spread slightly as compared to the 'good' JWT one.

Why don't you just use the O marker on the sprocket or even the key notch.
The scope signals showed a much larger angle discrepancy.
Must be slipped timing trigger.

Ever since Nissan teamed with Renault quality has turned to sh*t.

From the pictures timing is off by 1 tooth = 7 degrees.

I got the new sprockets/phasers delivered and tried to take some nice pictures. It was hard to get the camera perfectly aligned, but the B one might be very slightly off too.

http://files.zkpq.ca/2020-01-16/A.gifhttp://files.zkpq.ca/2020-01-16/A_zoom.gif

http://files.zkpq.ca/2020-01-16/B.gifhttp://files.zkpq.ca/2020-01-16/B_zoom.gif

I rekon if you heat up the ring and tap it one way you should be able to realign.
Then just recheck with scope to see if ok. repeat if necessary. Then weld to secure.
Strange no one on this forum has worked this out? Must be an 09 issue only and people just assume chain is stretched and change everything.

Good news! The last 2 weekends were spent cleaning and reassembling everything. Everything was a success, the camshaft sensor outputs are good, nothing leaks, and the car runs and drives with zero diagnostic codes :driving:

I'm planning on doing another flush of the oil and coolant soon to make sure any extra bits of gasket/dust/dirt/cleaners/etc are out since the cover was left open for so long.


Attachment 140629Attachment 140630
Attachment 140639Attachment 140640

Attachment 140631Attachment 140632Attachment 140633Attachment 140634Attachment 140635

Attachment 140636Attachment 140637

Nice pictures.

Start using 10w-40 and see if this reduces oil consumption.

Congratulations, way to push through and get the job done. :tup:

Great job cleaning EVERYTHING before reassembly. It's nice seeing that kind of attention to detail when chasing problems and fixing them. Kudos. :tiphat: