Shoji

As the title reads, I finished replacing the valve covers this afternoon on my 350z.

At the same time, I also installed the MREV2 and 5/16" plenum spacer from Motordyne.

After putting everything back together there was only one known issue: a vacuum hose that connects to the very front of the upper plenum had cracked PAST the nipple it slides on to. The Nissan parts department had closed before the hose had cracked.

I initially turned on the ignition and let it idle. It idled perfectly for 2 minutes, then started misfiring like crazy. I took it to Autozone and the guy verbally told me the following code descriptions:
- Multiple Misfires
- Intake Valve Timing Control Solenoid Bank 1
- Throttle Valve temperature sensor

The throttle valve temp sensor was definitely plugged in. I have no idea where the variable valve timing bank 1 connector(s) are.

My question is this: would the cracked vacuum line cause all of these symptoms/error codes? The vacuum line is definitely hissing extremely loud. I will order the hose from the dealership on Monday and install it on Wednesday.

Can anyone point me in the right direction for the Variable Valve Timing (bank 1) connectors so I can ensure that nothing was left unplugged?

Cux350z

iTrader: (162)

Check your coil pack plug wire colors to make sure you plugged them in right.
Check your cam pos sensor on the back of the heads
Check your cam pos solenoids on the front of the heads

Bank 1 is passenger

Shoji

I have confirmed the following:
- All coil pack plug wires are correct per the Factory Service Manual
- Cam position sensors in the back of both heads are plugged in.
- Cam position solenoids on the front of the heads are plugged in.

During inspection of the passenger side solenoid on the front of the head, I noticed the insulation on one of the two wires that connect to the solenoid was exposed. The wires are intact, but the insulation is not. I wrapped the wire with electrical tape.

I let the ECU reset overnight and started up the Z and drove it to a local Autozone again and got the following errors (mostly different errors than previously):
- P0300 - Random cylinder misfire detected
- P0123 - TPS 2 circuit high input
- P0223 - TPS 1 circuit high input
- P1135 - IVT control solenoid valve
- P0113 - IAT sensor circuit high input

After going back home I diagnosed the problems as much as I could. I went ahead and cleaned/sanded the engine grounds on the front/passenger side, reset ecu and started the car. Idled perfectly for 2 minutes. Took it for a drive and not even a minute down the road the symptoms returned.

Going to clean the cam position sensors on the back of the heads for ***** and giggles then return to Autozone for another diagnostic reading.

PS - I tried going through the "troubleshooting" methods after a MREV2/spacer install and I cannot get the car to go into diagnostic mode. I verify counts, accelerator pushes and I can not get the check engine light to blink. This is in regards to the following processes:
- Accelerator pedal released position learning
- Throttle valve closed position learning
- Idle air valve learning

reppintha510

iTrader: (2)

Fix the air leak before diagnosing the rest that will be the main culprit for the misfires then see what comes back

Shoji

Will do. Will provide updates once the replacement hose is received.

Cux350z

iTrader: (162)

Maf plugged in?

Main coil pack ground is that lug with the two lack wiringa that screws into the front top of the timing chain cover.

Shoji

MAF is plugged in. I ensured the two grounding contacts on the front of the engine were making good contact.

Right now just trying to figure out how I disconnected the connector for the rear cam position sensor. I have it out, just can't get the connector off. Argh

Edit: Photo of the damaged wire insulation for cam position solenoid on front of passenger side:

Shoji

Cleaned cam position sensors and put them back. While looking at the crank shaft position sensor on the bottom of the engine, I saw this:

(Point of view looking from the front driver's side wheel well)


Oil, oil everywhere... All over the crank shaft position sensor. Will have to wait until I can get it on a lift to see where all the oil is coming from. I had a new oil rear main seal put in when I had the clutch/flywheel replaced by the dealership less than 10,000 miles ago.

JaE35z

iTrader: (11)

eeek, in for updates...that doesn't look good

reppintha510

iTrader: (2)

Haha I bet u rolled the valve cover gasket when u put them on and that's where the oil is coming from. I would think that from experience. Double check the valve cover gaskets

0jiggy0

iTrader: (13)

Double check valve cover gasket. Fix the crack vacuum hose issue before you go crazy on anything else. It's a vacuum hose, go get a roll from napa/anywhere and cut it to length.

Shoji

My pride makes me not want to admit what I found...

Valve cover gaskets was exactly what I was thinking, too. I looked at the rear driver-side corner of the valve cover on that side and... yep, there's oil all around.

I tore the engine back down, used some RTV in the corner of the gasket and tried to put everything back together. Keyword: TRIED.

Come to find out, the bolts that secure the valve cover on had been over-torqued and just spin when I was trying to torque them down. Two of them I can't even get out anymore.



Does this mean I have to pull that head off to get it repaired? The bolts I could back out appear to have their threads intact but had a ton of metal shavings on it (like it ate up the threading on the heads).

2004Black350z

iTrader: (37)

Not good man.

reppintha510

iTrader: (2)

Wow how many did you pull the threads on? This can be fixed without removing the head. You can try a thread chaser first to see if u can get a bolt to bite but most likely you will need to tap hole to the next size and it will need to be as straight as possible. Good luck. It can be fixed but no offense I would take it to someone who knows how to do it. I have done plenty and it doesn't take long if you have done them before.

Shoji

I would venture to say at least 5 on the driver's side. I think I should be safe and have someone evaluate both sides.

reppintha510

iTrader: (2)

Definitely you could save some money and take them off so the shop has easy access to it and won't be as much in labor. To get those other ones out that are just turning stick a small pocket screw driver under the head of the bolt and lift up while unscrewing it and they should all come out.

Shoji

Towed the Z to the dealership, they quoted me at $600 to repair a total of 8 bolt holes in the heads and put everything back together. Not too terrible.

Edit: They also quoted me $120 to repair the Bank 1 Variable Valve Solenoid. This was the only outlandish quote.

0jiggy0

iTrader: (13)

Next time dont use a gun to put wheels on to put your valve cover gaskets on?

PainProblems

What was the fix for your problems?

i8acobra

iTrader: (6)

Seriously? This thread is 9 years old. The poster hasn't been here for 5 years.