Just assuming on what you allude with different colors:

Lifter rods - looks quite normal.
The lifter rods actuate the rocker arms (stamped steel).
Yes, if you remove them, need new nuts and torque to spec according manual.

Make sure you vacuum and clean out all that debris and gunk from the lifter valley. If stuff has fallen down into the block - not good.
I usually put a clean rag over the lifter valley before starting work and stuff full clean ripped off sheets of household paper into the intake ports. (cleanly ripped off squares so you can check that the whole paper has come out again.)

 

Thanks for the info... To answer georgelg, tno I don't have any compression\leak test results to go off of..I just noticed that one side under the valve covers was lighter than the other . But the side that is darker had 2 areas of leaking gasket. 1 front , 1 rear. Other side was intact. Any way to find out if I have bigger problems? We had a huge storm come through here so we gonna get back on it in the am. I will post some pics. Would there be a downside to get n the spider 🕷️ upgrade from a u pull it?
ps. We have covered everything up. Those pics are from when the intake first came off.....

 

The major engine damage candidates will all either make noise (ex: rod knock), generate random misfires that are not electrical (ex: bearings failing) or show up as compression problems. If you want to rule out a failing engine then do a compression test with leakdown, check codes and think back about any new strange noises. If nothing there then just get ‘er done. My LIM failure filled my crankcase with a quart of coolant and made a chocolate milk shake. Truck is fine after the LIM repair, they can take a lot.

You are the only one that can decide if you want to use a used spider for the upgrade. It’s a time and labor thing. If you have time, free labor and like tinkering then it may be worth it. If the opposite is true then new is probably best.


George

 

George,

If I'm remembering correctly, wasn't your case of a failed LIM mitigated by having used full synthetic oil in your engine?

As for the spider upgrade, when I did my LIM I had decided I was to keep my truck for at least 5 more years so I was willing to invest in new parts. And since I was doing the LIM and had it all apart anyway, I though I might as well do the spider upgrade then.

 

All I have ever used in this engine is PYB Penzoil Dino oil. I use semi and full synthetic elsewhere but not in this truck. I don’t know how many miles went on the truck before I found out that the LIM gaskets cut loose. There may be some luck involved in how the coolant gets into the oil and what the bearings see.

Our Toyota RAV had the head bolt threads cut loose at 167,000 miles (a common problem with this engine). The cylinders would hydro lock and not crank, filling the coolant every day, water in the oil. After around 500 miles like this I did a complicated repair involving drilling and taping all ten block threads with inserts, rebuilt the head, replaced water pumps, timing chains etc. Multiple oil changes and 120,000 miles later and all is good. That truck uses semi-synthetic. Almost 300,000 miles and runs like a sewing machine.


George



George

 

We are about to put these heads back on. What's up with the spot on the valves? From piston?

 

By spot's do you mean the brighter stains with the dark circle on the intake valves?
Looks like some sort of marking paint by the factory.

Very clean heads.

 

Yeah that's what I was talking about the white marks on there I didn't know if the engine was doing that or like you said from the factory. I'm at wit's end with this motor right now. We ended up not putting the heads on taking them to a machine shop and get them worked. You know new valve seats in the whole works. But now my motor is up in the air and we're going to be changing the timing chain and cover and oil pan gasket before it goes back in it's just taking a lot longer than I thought it was going to I'm stressed out to the Max and I can't stand to see my baby like that

 

If it helps consoling you...

... I now have two half built engines. The advantage of the small I4 is that it is light and I can handle it in two boxes. And the Blazer engine needs some checking and machining before first complete assembly and checking.