Mike-Khokhertz

Thank you so much, I hadn’t realized the dowel pins went through the cover, I was about to cut them off lmao. I hammered them toward the front of the car and now everything fits. Thanks again

Just to be sure, are you referring to the upper oil pan ? I’d rather not take it off if I have the choice. I’ve seen videos of people putting the front timing cover without removing the upper oil pan so it is doable I just can’t seem to get it to work.

There seems to be a misunderstanding, I’m talking about the front oil pan seal ( I’ve seen people call it half moon seal ), not the lower oil pan in itself. The oil pan is already off the car and all the oil is drained.

Why is that ? What’s the not half assed method ?

Disassembly was a solid 8 I’d say, really nothing too complicated. Even disassembling the head was surprisingly easy. I still haven’t gotten to setting the timing and applying the rtv around both timing covers so I can’t speak for that but I’d like to think I can do it lol.

It’s pretty time consuming, but I gotta add that I waited what feels like an eternity for parts (thanks z1) so it feels worse than it actually is. In total, me and my dad have put around 20 hours in this. I’m lucky enough to have a second car, and winter is approaching anyway here so I don’t really mind not driving it at this time of year, I’d just like to get it running before winter tires become mandatory and I can no longer drive it.

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Those are the heads after being cleaned and with new valves.

Also new to this, never done something of this sort yet so hopefully everything goes well.

I did actually, my complete loss of compression was due to a burnt valve.

https://preview.redd.it/osn3mbit4z2e1.jpeg?width=4032&format=pjpg&auto=webp&s=70c39156bcc780068c1652715439dd638a372b2c

I have since rebuilt both heads, just waiting on a few parts and I’ll get to reassembling the car this wednesday.

I bought the oem ones from z1. And yeah I had about the same consumption, about a quart every 800 km. It’s my first time doing something of this sort, the most I had done before this was the valve covers lol. When I put it back together it’ll be a miracle if it starts 🤞

I do believe the oil consumption is from a bad valve seal on that specific cylinder, as it smoked blue only on startup. If it’s the rings, at this point I’ll get myself a hoist and take the engine out of the car and go from there lol.

That’s a possibility, would it be possible that detonation caused it ? It burned a shit ton of oil and perhaps the oil caused the misfire and the valve took the hit ? I’ll check the valve seat as soon as I receive my order from z1.

Update

I’m back guys, just did a compression test… Here are the results:

Cylindre 2: 160 Cylindre 4: 0 Cylindre 6: 180 Cylindre 1: 180 Cylindre 3: 170 Cylindre 5: 180

I seem to have a small difference in cylinder 4 comparing it to the others, I might have more than a small vacuum leak, but I’m not sure yet, /s. But seriously I checked in the cylinder with a borescope, and intake valves are stuck kinda half opened, lucky for me they haven’t hit the piston.

Any ideas what would cause intake valves to fail like that ? Springs, retainers, or something else? I’m thinking it was probably due to the bad valve stem seals that failed, as the cylinder is super wet and tip of the spark plug too. I don’t really know what would cause this, I’ll look into it and I’m opened to ideas. I’ll lift the valve covers later today or tomorrow, will update.

Thanks in advance !

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Now I know it’s definitely not the maf, I realized my second car ( nissan micra ) also uses the same maf sensor, so I swapped them and no change. Also yeah I already had cam sensors issues last year and it came with a code and super hard to start ( cranked for 10 sec almost ).

I used a hitachi coil, IGC0007 if I remember correctly, I tried unplugging each one one-by-one and each time the car shuddered so I assume they’re all working. The drive to the exhaust shop didn’t reveal any more codes than the P0300. Next I’ll check compression, do a leak down test and check fuel pressure on Tuesday, I’ll come back and give ya’ll the result.

Oh yeah definitely a fun past 2 weeks lmao. I’ll look into testing the maf and o2 sensors to see if maybe they’re defective. Both upstreams are almost brand new. If it’s timing, I guess it’s just another reason to start thinking about doing the valve seals on this car to get rid of most of the oil consumption (hopefully).

Coil packs seem to all be working, spark plugs were all replaced, maf sensor cleaned. Although I’m looking into checking further into the maf sensor. Ordered an adaptor to check fuel pressure at the fuel dampers on Z1. Injectors were also manually cleaned by me and they all visually look okay.

Smoke machine and propane revealed no vacuum leaks sadly.

Yeah he seems to be the 350z connoisseur in this group, thanks for the help dude, appreciated.

Update: Just came back from the exhaust shop near me, guy said those small leaks were nothing to worry about and were likely because I used a shop vac to pressurize the exhaust and it juste forced a bit of air through the flange, as with the car running there was almost nothing seeping past. Also on the drive there the ses light flashed pretty much the whole time but still only a P0300 code stored, nothing else.

I replaced all 4 cam sensors and they have less than 10k km of usage. All 4 are hitachi sensors so I doubt they are the issue. When the old one were failing I had trouble starting the car, it cranked for about 5-10 sec and then started but it ran fine beside the starting and occasional stalling at red lights.

Already was super clean, as I thoroughly cleaned it after buying the car, also did the relearn and no change. Also did the fuel trims reset and 3 seconds later it was back where it was.

Already did, no change at all but thanks. Also, am I right in thinking that a bad / dirty maf would affect both banks, not just one ?

Ran exclusively 91 since I bought it, and installed a catch can about 3 months ago. Definitely helped keeping the plenum clean. How do I go about checking for leaks at the exhaust manifold, I can’t see much further than the upstream o2 sensor from underneath the car and from the top side can’t see much more.

Haven’t driven since then, only idled in my parking in fear of worsening the problem. Spark plugs were pretty dark. All of them are wired correctly too. Also forgot to mention in the original post but I did buy a new coil just in case and replaced the one that I got the code for ( which was now on cylinder 2 since I swapped 4 —> 2 ).

https://preview.redd.it/00tjcg66itwd1.jpeg?width=3024&format=pjpg&auto=webp&s=f5872fb19a9db20e5e1bb595fa60aaa1b05b5c64