TrekGTO

iTrader: (2)

I tore down my 05 LS2 and the pistons are so loose and timing chain is very loose. No wonder it sounds like Diesel when its cold is that normal for 8K mi never overheated 1 owner. Doing L92 heads and cam. Does the oil pump come off without dropping Pan on GTO?

xfactor_pitbulls

iTrader: (16)

Wow, did you do a compression check and/or leakdown? The main question...............why in the hell didnt you have that engine serviced under warranty before you tore into it? Dont quite understand why you would be putting heads on a "loose" shortblock, whatever you mean who knows. Something seems amiss with what you are posting.

TrekGTO

iTrader: (2)

Pontiac wont fix anything thats normal! i HAVE A GROCERY LIST they wont fix and been waiting for rep over a Yr

TrekGTO

iTrader: (2)

Oh ya this is my second NEW 05 GTO sounds same as first. I got refund on first one.

cabech984

iTrader: (11)

Thats funny, because I work at a Pontiac Dealer and have never heard of this problem, what have you done to your car mod wise??

TrekGTO

iTrader: (2)

I dont think its Funny 35k for new car needs this much work.
Bone stock except floor mats.
You never heard of piston slap on LSX Engin
Any one know if oil pump comes off GTO without droping pan?

cabech984

iTrader: (11)

Well sorry there bud, I aint got no piston slap on my 122k mile LS1 Car, my 80k 5.3L Truck or none on my old 99 5.3 ECSB and also none on my old 46k 99 Z28. I knew that there were problems in the Early Trucks but I just checked Service Info on Bullitens for 05 LS2 GTO's and Guess what? Nothing on knocks, Piston Slap. Nothing. And for you to get 2 cars like this, sounds like a fluke b/c Ive never seen one come through the dealership like that and its strange why they arent giving you a refund for the 2nd one. Oh yeah www.ls1howto.com should show you a way on getting that pump out, should be similar or identical w/ an LS2, good luck.

Loboost

iTrader: (1)

Just curious you say you tore the engine down or did you just remove the heads? If you can rock the pistons from the top with the heads off This is normal since the piston is not warrmed up. Also you would measure piston to cylinder wall clearance at close to the bottom of the piston skirt. I am sure there is nothing wrong with your engine. A lot of people mistake valvetrain noise for piston slap, and the valvetrain gets very noisey with longtubes installed. Because the tubing is so thin on headers compared to exhaust manifolds they transmit more sound.

Les

cabech984

iTrader: (11)

Too late now but did you call any other GM Dealers to see if they would do work to it? I dont think that you'd have much piston slap on an 05 LS2, think GM already figured it out by then.

Piston - Piston to Bore Clearance - Production
-0.022-0.08 mm
-0.0009-0.0012 in

Piston - Piston to Bore Clearance - Service Limit with Skirt Coating Worn Off
0.024-0.08 mm
0.00094-0.0031 in


as far as the Timing Chain, If you have doubts replace it with a beefier one.

TrekGTO

iTrader: (2)

Ya just puled the heads and timing cover in car we have a GTO day at Bradenton in a fiew wks. I dont want to pull the mtr. now I am building a 427 just wont be done in time. I had parts so thought I would use them.
When cold piston slap for a fiew mi.,realy bad when cold out. The chain was a surprise. I have installed with pan off never in car. The LS1 how to is down. I dont want to mess with pump unless it will come off.
Thanx

TrekGTO

iTrader: (2)

Ya GM wont admit when there is a problem and dont fix anything. Just say thats normal and damage car. First and last new car!