Need some opinions please
 

alright so I have an 03 Z and when I get on the gas hard it will burn oil BAAAAD like a puff of white smoke out the tailpipes bad, at first we thought it was the head gaskets letting a little oil in the coil packs and down in the cylinder but we replaced the gaskets and now about 2 or so weeks later its began again, this leads us to believe that while the car was out of commission (before I bought it the car sat for around 5ish years) the cylinders rusted and created pits in the cylinders letting oil coming through possibly valve stem gaskets settle in the cylinders and be burned. Anyone here have a little experience in mechanics and wanna throw an opinion in the ring? right now im looking at a complete level 3 engine rebuild kit from Z1 to help get her back in working order, but I think im going to have to go up in the bore size of my cylinders in order to bore out the pits ( if this is the issue)

any help or words of advice at all would be greatly appreciated.

I think you should perform a leak-down test on that engine before you start throwing parts at it.

come Monday we will, we are almost positive this is whats wrong and at this point im preparing for the worst, hopefully we are wrong and she passes in flying colors and deters this from being a multi-thousand dollar repair

Well there a couple things you should be aware of here:

- Burning oil is generally blue/blueish smoke
- Burning coolant is generally a white/whiteish smoke
- A bad head gasket will often allow coolant into the cylinder because the water jackets are located close to the cylinders
- 350z’s are notorious for the vavle cover gasket o-rings leaking, particularly the cylinder on the driver side closest to the firewall

Before you decide to dump an assload of cash into rebuilding that block you need someone to test it - If it comes back bad look for a used long block as they can be had for a couple hundred bucks. Don’t be nostalgic. This is a 350z, nobody cares about numbers matching on these cars.

white smoke = head gaskets ...

did you have the heads machined? if they're warped and/or they arent 100% flush with the head than it wont seal...

Correct. The OP is likely experiencing a warped head and gaps in the head gasket, allowing coolant to leak into the cylinders, and therefore, a white color coming from the exhaust.

Something else, I used a good amount of coppper gasket spray when I did my gaskets a few year back...High Performance Academy does these engine building webinars and they mentioned that spraying the head gaskets with copper gasket spray is a step in the wrong direction and could create a uneven mating surface ... I'm mixed feelings about the spray...

Its oil smoke, blueish tint and smells like oil burning

We did the test and each cylinder is burning oil, we believe its most likely my head gaskets and my valve stem gaskets and pitting inside my cylinder. Im going to most likely end up completely building my engine before building my suspension, oh well!

No nothing has been done to the heads, we preformed dry and wet leak down and know oil is getting In every cylinder we thing its a combo of head gasket valve stem and pitting in the cylinders, going to rebuild it and redo everything

we did leak down and think its not just head gasket thats ****ered, we think its also valve stem gaskets and pitting in cylinders, were going to do a rebuild and machine the block (if we find the pitting to be true) other wise its new cams and valves as well

Obviously many things going here...faulty head gaskets wont leak oil into the cylinder.

If you're getting oil into the combustion you AND you have pitted piston tops this could be an indication that you are mis-firing / detonating / ping'ing. Post up some pictures of the pitting (if you can) - is this in the cylinder walls or the piston face? Could also indicate that your rings are shot due to aforementioned detonation, thus the oil in the combustion...for how inexpensive rings are I'm sure theyre on your list.

we don't know and wont know about the pitting for sure until we completely take apart the engine, We think its the valve stem seals, I suppose that a blown head gasket could also help with the smoke, not getting oil in the cylinders.

In which case, pluck the engine and find a salvaged Z and swap it's engine ... You're in & out for $1000 to $1500

If he is going to keep the car, then let him build it. I built mine and is staying with me until it breaks in half.

Or you could just take the spark plugs out and check the cylinders for pitting when the pistons are at BDC using a halfway decent borescope. Still, if you've determined that you have a blown head gasket (personally, I'd do a hydrocarbon test at the radiator cap first, just to be sure), then you're going to have to take the car apart anyway.

An automotive borescope is a really useful too in diagnosis for issues like these.

I'm curious to know how they confirmed pitting??

I did the same thing with mine and I'd highly recommend ... a cracked upper oil pan yielded a built block, a haltech, and some FI...I doubt OP wants to go to that extent.

If you meant build as it get it back to OEM specs, it may be a fool's errand ... if this block was abused/neglected just salvage it out and swap a functioning engine into the car.

I don't think anything's been confirmed yet. Ripping an engine apart on a hunch is kind of like recommending brain surgery for someone who has a headache.

:White Smoke -coolant
:Blue Smoke- Oil
:Black Smoke- Fuel

Now if you get a "puff" and confirm its white, then Coolant is leaking from the HG into the exhaust.

Now if you did the HG's and it's still doing this. You may have a human error. If you do remove it all again see which piston/valve is cleaner than the rest and that would be the culprit side of things. Also you can perhaps see the gasket itself where a leak would be.

Just like someone already mentioned don't use any type of silicone, or spray adhesive on the gaskets. Make sure you torque them down proper as well.

Also if you did the HG in the kit should have come w/ valve seals and what not. You did not do them when you had the heads off? I would have also sent the heads to a local machine shop to check them out and polish them up.

If it is just a "Puff" i wouldn't worry about it to much until it becomes more though. Driving yourself nuts over a "puff" is not the way to live.. ;) haha!