Ashfall

Hey guys, kinda new to the car scene here, so please be patient with me. I greatly apologize this is so long, just want to be detailed. I recently had to take my 350z (manual transmission, Touring) to the shop to have some parts replaced (ended up needing a new transmission; the bolt holding the fork broke and caused a lot of damage, along with my clutch, flywheel, master, and slave cylinder going toast when I bought the car) When I took it in it had good power and acceleration, shifts felt smooth but the clutch was soft.

After they put everything in, they noticed that the car lacked severe power, and they were kinda at a loss. It was throwing a code for the Camshaft Position sensors, which they put new ones in, and it was still throwing the code even after repeatedly being cleared. They replaced the timing belts for free and made sure the arrows aligned there. (They had slipped two ticks when they put the flywheel in, and it made the car run a bit rough, but they said that it is good now) They said they couldn't figure out the issue and thought it might be a tune that was cleared from the car. (This was my first car purchase, and at the time, I didn't think to ask about the car having a tune since it was stock)

I went and rode with tech in it today, and the car needs about 2,000-2,500 in first gear to be able to move or it will stall, and needed an even higher rpm to shift. It felt incredibly sluggish and needed the pedal to almost the floor to accelerate, and when quickly pushing on the accelerator, the response time was slow from the engine, by like a second or two, noticeably different from when I brought it in. If turning it could stall.

I paid for the work and then drove it myself. It seems like the power steering is hit or miss, sometimes working but also going out. I drove it around the block parked it for a few and bought stuff at a store. I came back out and started it and with the car in neutral and the clutch in the idle sounded like metal grinding against metal. It made the grinding sound it with or without the clutch in, accelerating or not. It wasn't a constant grind but happened only a couple of times. A guy ran over and said he thought it sounded like the A/C compressor or the alternator seizing. I drove it back to the auto shop which was thankfully literally less than a minute away and left it.

TLDR Does this sound like a failure of an A/C Compressor, Alternator, or Power Steering Pump failing? Would maybe getting a tune also help? After a bunch of research, those seem to be likely options but I can't figure out how the camshaft sensors going off would tie in and why they would keep throwing codes.

I am really sorry this is so long yall. Thank you all so much if you read all this, I would greatly appreciate any answers and hope you have a wonderful day/night.

icer5160

iTrader: (4)

What year is your 350Z? How many miles? The more detail the better.

Since you mentioned the fork pivot ball bolt broke, I suspect you have a 2003 6MT?

There's a few fishy things about this shop as you describe the work they conducted.

"They replaced the timing belts for free and made sure the arrows aligned there. (They had slipped two ticks when they put the flywheel in, and it made the car run a bit rough, but they said that it is good now)"

"I came back out and started it and with the car in neutral and the clutch in the idle sounded like metal grinding against metal"

1) These engines don't have timing belts. They use timing chains, replacing the timing chains is a major amount of work. If they did this and afterwards you started getting CAM position errors, then likely they screwed up.
2) The crank position sensor reads a tone ring on the flywheel. If they didn't properly index the replacement flywheel with the crank, this will cause terrible running conditions like you described and the car should not be driven like this! Perhaps this was the component they mentioned had "slipped two ticks when they put the flywheel in"? Btw, changing a flywheel should not alter the cam/crank/valve timing, only the electronic ignition timing via the crank position sensor can be impacted.

I hate to say it, but I think this autoshop created a bunch of new problems for you. It really sounds like they botched the install and are now playing dumb and attempting to absolve themselves of any wrong doing by pointing to a "possible aftermarket tune." Worst case scenario they point to something else as the cause and charge you for it, when in reality they are going back and fixing their mistake(s). I would consider cutting your losses with them and trying a different shop with experience on Japanese vehicles.

If the vehicle ran smooth with good power prior to them touching it, then no tune should impact the running of the engine by simply replacing the clutch. Also, ask if they used OEM Cam Sensors, cheap aftermarkets will usually cause more problems!

"It seems like the power steering is hit or miss, sometimes working but also going out."
"TLDR Does this sound like a failure of an A/C Compressor, Alternator, or Power Steering Pump failing? "

It's possible the power steering pump has failed or seized, but I find this very odd/strange if the vehicle was running perfectly fine before you brought it in and only a "soft clutch" was a problem. A simple test would be to remove the accessory belt from the Alternator & PS pump (shared), and try spinning the pump by hand. Did the shop mess with the accessory belts? Doing a clutch job should not have involved any work at the front of the engine.

Do you have a copy of the work order you could share? Things like technician notes, parts used, etc.? Not asking you to dox the shop, but I'm curious if they used quality parts, or even the correct parts for your Z!

Good Luck!
-Icer

Ashfall

Hey Icer, thank you for the advice, I greatly appreciate it. It is a 2003 Six speed manual transmission.It has 161,915 miles on it. Engine is stock (as far as I know) the rims are not stock, I replaced the cranshaft position sensor, but other than that everything should be stock. I have done basic maintenance for like oil every 3000 miles and stuff but no heavy modifications. I will say the shop I took it to was Autopro, which I know people have mixed opinions on but in the past they had done very good work for my family and it was the only local shop I knew well enough to feel like taking it to and also one of the few that were close when my clutch was going out) I hope they arent being shady but I had my concerns when I drove it but hopefully its just a part going out and not them. :/

The part about the "Timing belts" was a typo on my part, they said chain I just accidentally said belt when I was writing it last night. It was off by two gear teeth is what I was told. I unfortunately have no technician notes, (UPDATE I just talked to the guys and they said they have notes and can send them) I have the paperwork breaking down the labor and installation parts cost. After looking at the cost breakdown the discount was the cost of the parts and labor for the new chain installation They bought and replaced the slave cylinder, master cylinder, and clutch. I bought the flywheel, and transmission (From Z1 motorsports) and had those installed. As for the flywheel causing the issue of the timing, im pretty sure thats what they mentioned. From what I remember they said I think something was loose or depressurized when they installed the flywheel, and transmission assembly, they ran the car, got the camshaft codes, noticed the timing was off, reset it and the chains, and installed new camshaft sensors and it still threw the code afterwards. (UPDATE, as I said I just talked and they said the guy who worked on it will be in I think tomorrow and I can get the exact order of operations from him on the troubleshooting, that way Im not saying from memory. Hoping I remembered wrong about the camshaft)

Unfortunately I saw your message after I had left it again at the shop, but I asked them to check and see if anything seized since the problem occured on their watch, and shouldn't have.

Here's a couple of the most relevant pictures I have, the rest are of the exterior or underneath the car but nothing that seemed prevalent to the conversation.

icer5160

iTrader: (4)

Ok. Well that helps clarify some things. Btw, your pictures didn't get uploaded.

If they replaced the timing chain set and were off a few teeth, that could cause a cam/crank correlation error and throw a false positive for camshaft position sensors. It's very likely you didn't have a problem with the cam sensors to begin with, it was an improperly installed timing chain set. Now, supposedly they realized their mistake and corrected this issue, but it's going to be difficult to prove one way or another without removing the timing cover. I wonder if their tech took some photos of the work?

As for the flywheel, there is a dowel pin on the mating surface of the crankshaft, this pin is used for alignment. Basically the flywheel can only go on one way, it should be ID10T proof. The Z1 performance flywheel has a machined relief hole for this dowel pin. If they didn't align the flywheel properly, simply put, many bad things happen.

I understand why you use the shop and it sounds like they are willing to make things right. Without being able to look over the car myself, here's what I suspect has happened.

1) Your timing set is still out of time (1-2 teeth), either the secondary chains between cams or the primary chain between crank and intake cams. This may not cause valves to hit pistons (some good news), but would negatively impact performance like you are seeing. The computer cannot rationalize what's happening, so it throws camshaft sensor errors.
2) Accessory belts have to be removed to access the timing chains for service. These engines don't use an automatic tensioner system, meaning the belt tension is set manually via the idler pulleys. If they over-tensioned the belts, it could cause premature failure of the bearings on items like idler pulleys, AC Compressor, PS Pump, & Alternator.

Re-doing a timing chain job is a major loss for a shop in the form of labor on these engines. So I suspect they may not have actually fixed it. But in order to prove this (without a scope), you would need to pull the front of the engine apart to inspect the marked links, and continue to rotate the engine until everything is lined up at TDC with the marked links at both banks of cams and the crank (could be a lot of rotations!).

If they have a shop scope and a skilled technician with the knowledge to use one, you can use live scope data to graph out the timing and firing order waveforms. By looking at the live vehicle data and comparing to a known good waveform, you can prove if the engine is out of time without taking things apart. Here's a good video showing the process (I think this Nissan quest is a 3.5L VQ35DE).


Good Luck!
-Icer

Ashfall

Transmission Juice had the forbidden Sparkle




Here are the pictures hopefully

icer5160

iTrader: (4)

Yeap!

Damn, you must’ve had some nasty clutch chatter when engaging 1st gear. Lots of hot spots and glazing on the flywheel and pressure plate. The clutch fork pivot ball is snapped off, known issue with 2003s. If you put in a new CD009 with the updated cast clutch fork, then you’re good! Won’t have that problem again.

Trans fluid looks nasty. She was toast, good call on full replacement.
-Icer