All,

Turned 85000 miles, got subaru noise, misfire on #3, and lots of smoke out exhaust after getting on it. Stumbles a bit at idle, feel a bit of power loss, etc...pretty sure piston #3 is shot.

I talked to a reputable machine shop and they said if I can bring them the short block, they will install new pistons for $250 if the bore isn't scuffed; more if they have to start boring for oversized pistons. I will take the block out first to examine for cylinder wall damage before ordering pistons.

I've never taken an engine apart besides oil pan, valve cover, turbo. A few questions:

- Is there a how to on taking the LNF apart and reassembling?

- Do I only need to go one size up on piston if scuffed? What is the size?

- Are clevite bearings worth it or stick with stock?

- Are ARP head studs worth it or stock good enough?

- How hard is it to get the short block out? Can I take the turbo and head off first, then drop it out the bottom with subframe?

- I've heard how hard it is to get the timing right on these cars. What preparations do I need to make to take the head off? Do I need to mark anything when taking the head off? Prolly good time to replace the timing chain and tensioner when putting back on.

Dumping all my money into a new business so need to be frugal. I plan on sticking with the stock turbo for now, but will upgrade the clutch to KY. Thinking about the phenolic spacers for im and tb....

I'm prolly missing all sorts, please let me know of any suggestions/advice. Also, please point me to deals on the parts...Thanks!

 

Mine's N/A and I just turned 84,000 miles and still runs like a top. What are you doing? Running to the store at 6,000 RPMs the whole way? Now since you're not quite at the 100,000 mile mark and there's no evidence of possible abuse, I'd check with GM and have them replace or fix the engine under warranty.

 

Seriously? Just because you can't hit 90 mph without a straight stretch of road and a week off work doesn't mean he has these issues. And don't you think he wants GM to fix it but maybe he doesn't have any warranty? Come on man...
OP, you should be able to drop it all under the car and roll it out without taking anything off first. I think exsoccer posted some sort of build book on the lnf buy I can't remember, might want to pick up a haynes manual for that.

 

I don't this a few times, I take the head off, turbo, downpipe for room, then axles come out secure brake calipers drop the subframe, remove lol by lil. From motor like the ac. Condenser and stuff, place Jack stand under engine but keep it low use a jack on the trans as u unbolt it from the engine, whole side will lower the engine will be caught by ur Jack stand and u can muscle the trans down, then remove all connectors. And stuff and prepare to drop the motor place Jack under motor I removed my oil pan so it wasn't damaged, then unholy the upper engine mount and lower motor your done, sum steps in I skipped like draining fluids removing the ecm and disconnecting other things but that's the meat I guess.

 

Timing is not hard to do pay attention cleverer bearing you won't need gm. Bearings work fine, if you bore you will go to 86.5mm stock is 86mm just replace the sleeve that's damaged. Have the block honed. And New pistons . Installed phelonic spacers r not bad they work, ky. Is a gud.clutch.choice and arp. Headstuds r a gud security investment

 

You can go on zzp website and get the gen3 ldk. Short block for round $1,700 or just drop it block like I said b4 replace the damaged sleeve hone and replace with upgraded pistons and rods since motor is out, compare that cost to boring out the cylinders to fit.the 86.5 pistons. Since ur trying to b cost effective.

 

what tune u running and how what psi were u pushing on the turbo? stock turbo?

 

Buy a ldk short block from zzp

 

LOL, you sir need to keep to the N/A forum.

As for warranty, it's expired. Also, I used it once for piston #4 and the dealership left bolts loose, cracked the a/c compressor, cut into map sensor wires. Dealerships sucks!

 

exactly, if piston 4 went, not 3 went, wats the point of fixing 3 andh aving 1 and 2 go! LDK! LDK! LDK!

 

Replacing all pistons.

It was on Trifecta 24 psi e47 tune.

 

There was a thread on ring gaps that I can;t seem to find, please link if you know.

What about the clevite bearings?

Thanks

 

Most likely your cylinder walls will have some damage. I would just go with a LDK short block from ZZP. It's $1500.00. Use your current head, other items. I'd also re-look at your tune and to why it was detonating to cause it to blow out a piston.

 

I believe it was from me getting on it too early after ecu reset, long term fuel trim was at +3%

 

Not too insane though. Listen, you got 86000 miles on a stock motor. Nothing to be ashamed of. Things will go eventually.

 

I know your pain from bumbling dealerships and bad warranty repairs all too well...

 

If your being frugal. Go with GMPP clutch while trans is out. Will hold anything you can throw at it on stock turbo.