AKA_04

OK, I lost my VAIS bolt and ended up replacing the cylinder head on the left bank. As I was reassembling the exhaust I noticed that the precat on the right side was in excellent shape. After I started the car I noticed a pretty strong gas smell and had a rough idle. I let the engine idle for around an hour hoping that the ECU was adjusting to the new parts. The check engine light started flashing when I did a test drive so I drove to town (10 miles) and had the dealership run my codes (for free).

Came back with a multi-cylinder misfire (duh) so I drove home losing power the whole way. Initially the shop manager and I thought that carbon deposits in the right bank may have caused the misfire so I started taking the engine apart again to pull the left head and clean it up. My oil was thin and smelt like gas and my right precat looked very bad now so I decided to do a 1/2 a$$ed compression check by putting a spark plug in one cylinder of the left OR right bank and turning the engine through TDC and comparing my results. At this point I had removed the timing system and pulled the cams so the heads were sealed. The left bank had good compression, the right bank (with the bad precat) would turn through TDC with little resistance -- I repeated the test to be sure. All this screams bad rings ruined by the precat correct?

I've now pulled the pistons and ordered rings which are being overnighted. I'm curious to know:

1. Should do a light hone of my cylinder walls? I can see crosshatching clearly on all cylinders except for cylinder 6 where I think there's just a touch of glazing (see pics).

2. Should I clean the carbon deposits on the sides of my pistons? I'm thinking the carbon should be left on the side to keep my pistons from moving around inside the bore. No measuring tools, the pistons are nice and tight in the bore though.

The engine has 181k and I'm 90% sure the original owner ran synthetic oil, the engine is very clean and was NEVER pushed. The original owner is actually my friends mom and she takes care of her stuff.

Notes: Replaced my valve seals and hollowed out my precats already (going to do the sparkplug anti-fowler trick to the O2 sensors as well); this is all being done in the engine bay. If you support the tranny w/a jack and pull the drivers side engine mount bolt you can lower the tranny a couple inches and tilt the left side of the engine up. Then use some rope to pull the engine towards the front of the car and hold it there, then it's pretty easy to slip the timing chain covers on/off this way. A full write-up will be done when complete. Also, pretty impressed with the DIYers on this site... WOW.

[s3]

iTrader: (1)

You are this close to doing a rebuild, might as well get everything cleaned since you already have it apart.

AKA_04

Thank you for the response. Could you clarify which parts I should clean? I took a razor blade and a scotchbright pad to the valves already. Planning on using acetone to clean up the intake manifold. What else sir?

AND, skip honing?

Thanks again!

[s3]

iTrader: (1)

1) use carb/throttlebody spray to loosen up any carbon build up you see

2) do a light hone if you have the pistons out

3) inspect crank and rod bearings for wear - honestly i would replace these if the engine is at that mileage, its only like $40 for the crank set, the rod bearings are a bit more.

4) if the engine is on a stand, crack open the oil pan clean that out

5) check all seals for leaks, replace if found

There's probably more, but those are the most basic things.

Remember to replace any rusted/rusty bolts you find, always torque everything to spec and anti-seize is your friend.

AKA_04

I was really hoping to avoid honing but I shall hone if nobody talks me out of it.

The engine is the bay and the oil pan is off--how else would the pistons be removed? Not trying to flame, not at all; I have to ask what your experience with this engine is though? Or, is there a way to remove the pistons without pulling the pan??? Pics are pretty clear on this one, did you see them by chance?

Bearings: can't afford but good advice. Planning on doing a full build in a few years, this is just to get me by for a while.

Seals: Replaced most of them already.

Rusted bolts: Check. I have a tap set, I'll be running all of my bolts/nuts through the correct tap to clean off any debris before applying anti-seize. Will replace any that are rusted.

Once again, thanks for your time. School starts Monday and I'm wanting to do this well.

[s3]

iTrader: (1)

Thought you had the engine out on a stand, but in any case I have pretty much taken an entire 4th gen apart, engine, body and pretty much everything else on it.

I do more work on my z32 though, which is a lot tougher, makes pretty much anything on the maxima like a walk in the park.

AKA_04

Once again, thank you. I'd hoped that you had skimmed my initial post
but you never know when an internet know-it-all will chime in. z32? Nice car sir. Always liked the body style... and turbos.

MaxxedOutt

iTrader: (1)

If you're replacing rings, it is better that you do hone, this will remove the glaze and allow your new rings to seat and beeak-in properly. Yes, it's a little more work, more mess, and definitely more cleanup, but, you will have a better running engine! Dude, I admire your tenacity for taking on a project like this! You remind me of when my brother and I would do this all the time! We would remove, rebuild, and replace our engines almost overnight because we had to be at work or school the next morning! Yikes! Crazy times! Good luck!

AKA_04

I've done a very light hone, just enough to see scratches in the surface. The hone had brand new stones and I made about 5 passes up and down. Heads are on, cams in place, putting everything else back on tomorrow. Really hoping this works... thanks for the encouragement.

BTW, cleanup really wasn't too bad. I positioned the crank in such a way that I could put a small towel at the bottom of the cylinder to collect anything that didn't stick to the lubricated cylinder walls. As near as I could tell nothing fell on the towel, still cleaned the crank though.