lq4 teardown - how far to go

[dns87]

I have a 2001 LQ4/4l80 out of a 2500 HD truck that I plan on installing in an 87 monte carlo ss. I plan on using LS6 intake, 243 heads, headers, change cam and change the oil pan (for clearance).

I have removed the intake and the heads so far and will be removing the oil pan. Now is it worth tearing into the shortblock or do I leave it as is? The previous owner said the truck had about 30K miles not used on the road. It was a mine (above ground) service truck....so probably lots of idleing.

If I redo the bottom end then maybe I should go with different pistons and reuse the 317 heads....

any opinions welcome.

 

[B.G.]

any opinions welcome.

A leakdown test prior to tear down tells you lots. Leave the lower end alone, but you might as well put some arp rod bolts in just because-If you plan on really spinning the thing... And if you're not going to spin it, save the LS6 intake for next time. My .02

 

[dns87]

I did a leakdown test before teardown and the numbers were all over the place....from 19% to 90%....could hear some leakage through the valves and a bit through the bottom end. Now the engine was cold....not run for about 2 years.

And the reason for the ls6 intake is for more hood clearance.

 

[Bill in NC]

Just remember if you remove the rod bolts to inspect the rod bearings they will need to be replaced just like the head bolts. Good luck with the build.

 

[dns87]

That's the cross roads I'm at.......do I pull a couple of caps off and inspect bearings for piece of mind? Then I need new bolts. Should I bring it in to a machine shop and get the cylinders honed, then new pistons....the list goes on. Still thinking/researching but so far I'm leaning towards pulling it apart.

 

[D&A Machine Shop]

The early 5.3s And 6.0s had a problem with the knock sensors that will cause them to detonate and beat the rod bearings out so it is a good idea to atleast check the rods.
You are so close that I would go ahead and pull it down the rest of the way.
That will give you a chance to have everything checked out and the cylinders honed. If you use ARP bolts then you need to have the rods checked after they are installed because they can distort the big end of the rod. Usually just needs to be touched up on the rod machine nothing really major.

Andy

 

[dns87]

I did decide to tear it all the way down. The rods were already numbered, assuming it was redone in the past. The rod bearings look like new and you can still see cross hatch marks in the cylinders. Didn't remove the main caps yet but will get everything checked out at the machine shop. I checked the p/n on the installed pistons and they are stock 4" bore.

If the crank checks out ok, I'll reuse it and get after market rods and forged flat tops while I'm at it and shouldn't have to worry about the bottom end for a long time.

 

[dns87]

The early 5.3s And 6.0s had a problem with the knock sensors that will cause them to detonate and beat the rod bearings out

so what's the fix for this? Are the sensors at fault? should I replace them?

 

[B.G.]

The early 5.3s And 6.0s had a problem with the knock sensors that will cause them to detonate and beat the rod bearings out

so what's the fix for this? Are the sensors at fault? should I replace them?

I'll trade you some for your stock rods/pistons/bearings. How many sets do you want.

 

[D&A Machine Shop]

Sorry I should have explained it better. The problem is where gm placed the knock sensors, the earlier motors had them in the valley
and the way they are in the vally cover it lets water to collect in around the sensor and causes them to corrode and fail.
yes replace them and take the little foam cover off of the wiring harness. this will let any water that collects in there to evaporate off.