hpbob1

iTrader: (1)

Hi guys,

I bought a 2002 Lq4 from a junk yard to go into my 74 camaro. When I bought the motor I turned the crank with a wrench and it turned fine. I was hoping I could just put a cam in it and change over the intake to a car intake. Later I Found out the motor was left on its side without an exhaust manifold for a few weeks and there was a light rain. Didn’t want to pull the heads to examine the cylinders but now I have to. I will pull the heads and check for water or surface rust from water on the cylinders etc.

I pulled off the valve covers and found as I face the front of the motor on the engine stand the 3rd rocker arm from the rear on the left side of the motor is loose with about a 1/8th of an inch clearance between the rocker tip and the valve stem. I can twist the loose rocker arm a little side to side maybe a 16th of an inch on the rocker shaft. Is this normal play? I can’t tell from the other rockers cause all the other rocker arms are tight against the valve springs. I hope this isn’t the loose rocker trunion bearings issue I have read about.

Does this sound like a collapsed lifter issue? I was going to change the cam anyways. Could all the fluid have leaked out of that 1 lifter causing this looseness in the rock arm? I am guessing it has to be more than the oil leaking out of that lifter. I may have to replace one of the lifters.
Now I have to pull the heads but I want to diagnose this lifter/rocker arm play issue before I loosen all the rockers and remove the heads. The rocker bolt on the loose rocker arm seems to be tight like the other rocker arm bolts. Is this a possible wiped factory LQ4 cam lobe issue? Any ideas or help will be greatly appreciated. I am hoping I can just replace a lifter or lifters and cam, then put the heads back on with new head gaskets and cylinder head bolts. Of course this depends on what kind of shape those pistons and cylinder walls are in too. Thanks guys.


Hpbob1

Darkman

iTrader: (2)

It could be a collapsed lifter or perhaps a valve that is bent and stuck partially open. In any event, since you are pulling the heads and replacing the cam I am not sure what should be diagnosed during the tear down.

chrisfrost

iTrader: (8)

What darkman said , You will undoubtedly see what the issue is at some point in You're tear down . Remember for it to be stronger , it must first be torn down ! he he seems to hold true in a few different ways in life . Good luck

garygnu

lifters don't cost too much.

hpbob1

iTrader: (1)

Hi vodas00ss,

The little bit of water went into open exhaust ports on 1 side of the motor from a light rain. The motor was only outside a for a few days in a usually dry climate. The water would not get to the lifter bore area. The intake and valley plate are still on the motor.

Hi Darkman,

I know this is a newb question but what does a collapsed lifter look like as opposed to the other lifters? I am sure if its a wiped cam lobe it will look different from the other lobes. Something had to make that 1/8th of an inch gap.

As I dis-assemble the top end I want to find the cause. Hopefully no metal parts or shavings are in the motor (like bearings from a loose rocker trunion?). I will just have to examine everything as I take the heads off, drop the oil pan etc. I am only removing the oil pan to replace the rod bolts with stronger ones and a new oil pan for my cars chassis. I hope I won't have to dis-assemble the bottom end or need honing of the cylinders etc.

Anyone know if the rocker arms usually have a side to side play (about 1/16 of an inch) on the rocker shaft before the rockers are tightened down? Bear with me guys. First time taking apart a motor other than reading a bit on how to do it.

Hpbob1

Darkman

iTrader: (2)

The rocker arm play from side to side is normal. You should of course check the trunions when you remove the rockers. When trunions spit out their bearings they usually land first in rocker area of the head. A trunion upgrade kit is a good idea if you have the coin.

If the lifter on the one cylinder is collapsed it will not have the "spring" that the other lifters have. Lifter sets only cost about $130, while individual lifters run $30-$40 each. If it were mine I would plan on a new set of LS7 lifters which are the standard OEM replacement. They are generally considered reliable.

On the rod bolts - use the Katechs if you are not going to resize the rods. You can use ARPs if you resize the rods. (This is based on the respecitve recommendations of Katech and ARP).

hpbob1

iTrader: (1)

Thanks darkman. Oil looked good when I drained it. No milky light brown color, just normal dark looking fairly clean (not real old) oil. No loose trunion bearings in the valve train area under the valve cover either. I will pull the heads next weekend. So far this motor looks usable for adding cam, intake, and lifters without a re-build. But pulling the heads next weekend will tell the final tale. I did'nt want to pull the heads cause now I will need new head bolts and a MLS gasket set and a block and head surface cleaning. But we all know hot rodding is full of the unexpected!

Hpbob1

Whiteaw57

iTrader: (2)

youre on the right track. keep up the good work, ask questions if you arent sure and be sure to cross all the t's and dot all the i's. the cleaner and better you put it back together the longer and better itll run. Good luck!

Bumpers

iTrader: (10)

Its better to pull the heads now and check and replace what needs to be done than have it in the car and then have a problem with it. if your pulling the heads off I would go ahead put some ls7 lifters and ls2 trays in it while its apart, it wouldn't be a bad idea as I've seen a few lifters come apart and wipe out the cam. When you pull the head I'm sure you will find whatever your problem is

Whiteaw57

iTrader: (2)

^^^x2