dkiller2135

I got a early 99 lq4 engine. I bought a rebuild kit for a lq9 escalade. The engine shop pressed the pistons onto the rods. They did not use the retainer clips supplied with the flattop pistions. All seemed fine until i got the engine back into the car and the wrist pins all walked to one side of the block and busted the pistion and shattered one rod and crack another all cylinder wall are scared from the pins. Has anyone have or heard of the issue. This wrecked my intire build.

redbird555

iTrader: (14)

The lq9 uses full floating pins where as the lq4 uses press so there's your issue you either need lq4 pistons and rods or lq9 rods and pistons

LS5.3stang

iTrader: (4)

i think i would make a call to that shop and get u lawyer. that is there fault they should have known that wouldnt work

lizeec

iTrader: (57)

Same could be said for the OP that ordered and brought in the wrong parts the parts to the shop, he should have known that that parts combination wouldnt work, even the person who sold him these parts should have known as well and asked the questions on what the parts would be used on? OP needs to take the responsibility of having purchasing the wrong parts for his engine, whenever a customer brought in their own parts, it automatically eliminated any warranty on parts and labor, you never knew what parts they brought in and where they got them from. You don't know if they are clearance items or defective items. Sometimes when you try and save money it will cost you a lot more in headaches and grief and more money.

Very few shops can survive working only on LS engines, and those that do prefer to use their known trusted suppliers and vendors, and charge accordingly, in cases of possible parts failures or labor errors, a certain amount is built into heir pricing to cover these mishaps. Most shops work on all makes and models and can't be experts on every single make and model of engine.

KCS

iTrader: (20)

That's not exactly true. With a press fit rod, it doesn't matter if the piston is meant for a floating pin or a press fit. The piston still needs to have clearance in either case, but the rods need to have enough press fit to retain the pin. If it were a floating pin rod, then the pistons do matter as they must have the groove to retain the locks.

Sounds to me like the shop is at fault.

niscur29

I think press fit pistons are .945 pins and floating are .943. If op bought and lq9 kit it would have come with pistons setup for the floaters. So even if the rods were press fit the shop should have still been able to get the smaller floating pin in and the pistons should have had retaining clip slots in them. I believe the rods are the same so the shop should have put the clips in if the pistons came with provisions for them. This is one of the reasons I do this **** myself. This way the only one to blame is me and I don't have to wonder who else f'd up along the way.

redbird555

iTrader: (14)

This is what I meant sorry for the confusion I was typing on my phone and stepped on myself. I think both are at fault here seeing as the op bought a kit for an lq9 which brings pins and pistons but i also think the shop should have checked it. although i understand about the no parts and labor thing being the shop didnt sell the parts

96capricemgr

iTrader: (1)

I thought the pressed/floating thing was YEAR dependent more than it was an LQ4 vs LQ9 thing?

KCS

iTrader: (20)

The pins are all the same diameter, it's the pin bore in the rods that are smaller to give it a press fit. The floating rods have a larger pin bore for clearance. The OP's parts selection is a moot point as the pins would have been the same diameter whether it was for a LQ9 or a LQ4. At this point, it still sounds like the machine shop did not check the pin fit and is therefore responsible for the failure.

KCS

iTrader: (20)

At some point it seems like all engines got the floating rods. A bunch of the newer 5.3L engines have the floating rods too. I think for certain years, there a distinction, but eventually they all got these rods.

redbird555

iTrader: (14)

I have never looked at an lq9 floating pin but floating pins that have seen in outboards slide smoothly in and out of the bore. The op says they were pressed in, this leads me to believe he tried to use press fit pins with lq9 pistons. Which again he should have checked and so should the machine shop

kcs: i like the sig pic lol

KCS

iTrader: (20)

The main difference between the LQ4 and LQ9 pistons are the dish, or lack thereof. The pin bores should be the same as in either floating or press fit, the piston and pin should have a clearance. The pin bore in the rod is what the pin gets pressed into the rod, so it's okay to use LQ9 pistons with a LQ4, or any press fit rod for that matter. The thing I think is messed up is that the rod did not have enough press to secure the pin. It was either too loose when the machine shop got it, or the machine shop honed them out making them too loose.

Glad you like my sig. It's a 700whp ZL1 that my company built.

dkiller2135

Shop is gonna. Tear it down this coming monday and let me know something. Whether the block can be bored or is it needs replaced. My father uses them in bulk for toyota 22re heads and blocks so i firgure i would use the same bussiness. Im still a bit confussed. Would this not have been fine if the retainers were used? The lq9 rods are not pressed to piston. Just assembled by hand with retainers? So i need all new rods just to run the flat tops?

KCS

iTrader: (20)

You should have been okay with the parts you had. The pins are not pressed into the pistons because they are supposed to have a clearance between the two. In a press fit pin setup, the ID of the pin bore in the connecting rod is smaller, which creates the press fit. The pin is slide into the side of the piston by hand, and then pressed through the pin bore of the rod and into the other side of the piston. The pin cannot come out of the bore because its secured in the rod. If your pins were pressed into the rods and still came out, there was not enough, if any press fit.

dkiller2135

I hear you. Pressed to rod. And on a floating pin (like the majority of pistons) you could slide it though the pistion and rod without the need to press and just install the retainers all by hand . These were pressed and i asked about the retainers not being installed. I beileve the simple fact that the retainers were not installed and he remembers me questioning that, they will do what it takes to make things right.

ericwilloughby

This is odd. Either the things were pressed in or not. There is no middle ground. Who ever assembled the rod to the piston knows and is responsible

dawgs74

I'd burn that place to the ******* ground.....

CattleAc

iTrader: (7)

Easy Francis...this is a 4 year old thread...OP has probably gotten over it by now....

ericwilloughby

So, what happened?

dawgs74

I went and burnt that **** down.....lol