Turbo Johnny

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Hey all, been doing my research and am 100% confident I have all the info I need to install Wiseco pistons in my 2010 LNF. I have a parts list complete with gaskets, oil pan gasket stuff, cam, crank and head bolts/studs, etc. One question circles around my head and I thought I'd get some advice.

The piston install is because like the genius I am, I ran Trifecta's budget tune and dogged the crap out of my car for 2 weeks in hot weather. I was checking for knock on my RPD and I saw some but I always saw some on stock too, meh. Always put 93 Shell in my car so gas quality is not an issue. I lost most of my boost and couldn't get over 5 PSI. I checked the DP, I blew out the first cat from all the fuel and/or blowby and chunks collected in the restriction by O2 sensor (stock DP)... STILL had low boost. Thinking my turbo was to blame (ton of shaft play) I swapped it for a turbobay K04-R. Still low boost, daaaamnit the 2nd cat is probably the issue!! I ran open turbo and my boost was back haha so I smashed out the 2nd cat too, back in business right??

No... a few weeks later, I saw a ton of smoke after WOT. I checked my RPD, when I boost for more than 3-4 seconds and my AFR is at 12.2 (rather rich from what I read) when I release the pedal between shifts, it STAYS between 10.9 and 11.2 for a split second and I see tons of smoke! This 12.2 and lower AFR "power enrichment" during WOT is when smoke happens, if I go 80% throttle or so I avoid the smoke, OR if I WOT boost for less than 3 seconds. So it's fuel related that blew out my cats because of this god-awful tune. Yay. I'm thinking rich as **** condition of spraying fuel for a split second after WOT onto a super hot piston overworked the rings or ringlands, because...

I read 120 PSI on cylinder 1, all others are 150. A cap full of oil and cyl 1 is back at 150, so the rings and/or ringlands are shot. I'm assuming the cylinder liners are OK but won't know until I either remove the head, OR find my damn borescope I bought a few weeks ago (I'm moving so **** is everywhere!) Looking forward to fixing the compression issue, upgrading my pistons and after break-in, getting a real HPTune...

MY Question... As per this thread where a user suffered ring failure and got work done, if you scroll down you'll see pics of the head removed BUT the turbo is still installed?? As this possible to do? I ask because I did a turbo swap recently and I'd like to emulate the dissassembly process of that post because then the DP, O2 housing and turbo can stay in the car and save me time on the job, I'd like to get this done in a weekend. Also, I won't have to replace as many gaskets.

The only thing I can think of is when the VC comes off, there's more clearance to get to the exhaust mani bolts? Perhaps all 10 can come out on the head-side as well as the 4 that mate it to the turbo? If this is easy to do then great, otherwise I will plan accordingly for pulling the turbo. I was just hoping to save 4 hours or so of labor.

Thanks in advance.

KMO43

The reason why it's running so rich at wot is because with the cats out the 2nd o2 sensor is seeing more heat and going into a cat overtemp mode. 150 ea and a 120 isn't that bad. I'd throw the money on a Hp tune first

TurboWood

Don't forget to plan for gaping the rings. That was a surprise for me when I opened the box and read the directions.

In my case the lower rings were ok, but the top ring was too small by about 0.006".

Daniel

Turbo Johnny

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I guess I'll rock this info and double check before installing! I will be ultra neurotic during the whole process and put her back together perfectly

Turbo Johnny

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Duly noted, thanks for the technical reply. I plan to go Cat-less and get a better tune yes but, I can do that when only at 120ish PSI?? I don't misfire in that cylinder BUT I must be getting a decent amount of blow by, as there is a bit of oil in the piping before the turbo. Not just on the housing, but I put a q-tip up in the breather line that attaches to the turbo, that whole line is seeing a fair amount of oil. I'd imagine that WOT'ing the car whilst having lower-than-normal compression is to blame.

I will be checking my cylinder in the next few weeks with my borescope to see if I can find any sleeve cracks. This is my only DD so when she comes apart, she's going back together quickly, I don't want her out of commission for more than a week. I am planning accordingly and after I move, maybe October-ish or November, I'll have a week off of work so 10 days straight to get her done. Knowing that my sleeve is OK in advance will help get the car done quicker! Though if my sleeve was cracked I'd be miss-firing, yes?

Omiotek

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If you sleeved was cracked even a little bit it would be running on 3 cylinders and sound like a subaru or it wouldn't run at all. Usually when sleeves go in these cars they go big and make the motor unturnable. Chances are you have a cracked ring or leaky valve stem seal. Did you do a leak down or just a compression test?

Turbo Johnny

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Wow well good to know the sleeve is OK! Now when I take her apart I can be fairly confident I can just pop the pistons and rings in and be good, whew.

I only did a compression test. My conclusion of the rings being bad based on a compression test alone is due to hitting 120 on a dry test but with a bit of oil hitting 150 no problem. I was contemplating valve stems as a possible cause as well but the clear difference in results with just a cap full of oil swayed me. I also have a brand new head on the car, only 20k miles on it. Was installed by GM under warranty 2 years ago and the car was running great until that hot day and it ran lean.

Thanks for the replies everyone. I recently moved and with the chaos of life haven't looked much further into the issue as the car is 100% driveable I just don't beat the **** out of it anymore. My friend has a 2 car garage I can lay the balt down in to do the repairs but I just don't have the time nor the 2nd car. Soon.....

Turbo Johnny

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Wow, 6 months later and I still haven't done this yet! Saving for a wedding I still want to do this... I can't believe I asked if this can be done leaving the turbo in the car, what a joke, for the work involved the extra 3 hours it takes to pull the turbo is minuscule.

I wish I had the ability to pull the engine/sub frame and work on it externally, then I can do the clutch at the same time! Any one know how high you have to get the 'balt off the ground to do this? A lift is most likely needed yes?

KMO43

I had it off the ground as high as my jack would lift from the front of the subframe had room left no lift needed

tomj77

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If ur not running a cat, remove second o2 and delete codes. Then u don't have to waste money on one

Omiotek

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Unless you have emissions in your area then its better to just keep it

tomj77

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Yes I keep forgetting about those unfortunate people

Turbo Johnny

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Thank god, no tailpipe checks in NY...

Turbo Johnny

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Since I hate loose ends, I wanted to come back and finish this thread. New pistons installed and the car is running awesome! ZZP, gen 3 pistons with rings, only $150, what a steal. I put 50 miles on her, changed oil and cut open filter, no particles and the oil was clean. Coolant has no oil in it, oil has no coolant, no smoke, nothing, perfect. I've since put on 200 miles and she feels and runs fine. Waiting until I make time for a compression check to see how it turned out, I threw 15 lbs of boost at her last night for 2 seconds and she felt fine.

Thanks all for your advice and wisdom.

Jhonnevakuson

Anybody knows where is the most affordable place to get a Hp tune near Winston Salem, NC? If not, can someone at least tell me the average price for them?

Slowbalt2000

iTrader: (1)

Please start your own thread in the proper section.

tomj77

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man forgot about this thread. dumping boost for no reason is most likely your bpv solenoid is bad, if you still use it. bypass it. the loosing all boost with the slightest decrease in throttle pressure is 100% normal. it may feel like its slight, but if ur not holding it or slowly pushing it down, backing off will close it and ur engine will go into vacuum and u loose boost.

steelmesh

Unless you're a dealer tech doing an OEM dealer piston replacement (where the service procedure does not include checking the gaps), piston ring gaps must be checked/adjusted always right before you install the pistons (as in: not before finishing the bores).

On that note, I had custom Diamond pistons made for my LE5 build, the ring grooves (side clearance / axial clearance) were under spec, zero clearance. I didn't catch it until a few months later on top of trying to get my car running by a specific date on top of I diy ceramic coated them (therefore it's my fault is the assumption), I opted to touch up the grooves myself in a 4-jaw mini-lathe using the side of a parting tool. Lesson learned, if you ever purchase custom pistons (even from a dealer like ZZP), check the ring groove clearances right away so you can work with them to correct it immediately. If you have feeler gauges, you have no excuse [after reading this] not to check the side clearance because it is very simple. I think ring thicknesses are standard, so possibly you need to lap them or have a machinist surface grind the rings...otherwise the piston manufacturer can probably touch up the grooves if it's their fault.

steelmesh

Dear Lord, it's tomj77 fault I replied to a 2015 thread