csxfbird

iTrader: (5)

My 2003 Sierra with 5.3 LM7 has 86k miles on it, and recently gave me a low coolant light. I last flushed the system about 5 years/20k miles ago, and it passed a 15 lb pressure test recently with no issues. In researching potential areas for coolant loss, I learned about the water pump being a common leak area, and then opened the can of worms on the Castech cracked head issue.

I pulled my valve covers this morning - I am trying to track down a borescope in the hopes I can look for the Castech casting logo before pulling the rockers. The driver side looks clean and nice, but the passenger side seems to have a more orange/bronze color to it with a slight film on the inner valve cover. In the opinion of LS1tech, might this be a sign of a slight leak in my head?

Driver



Passenger



Driver on left, passenger on right

MY_2K_Z

iTrader: (1)

Every ls motor I have pulled apart looked like that. Not sure why one side is always "cleaner" than the other but it is.

Darth_V8r

iTrader: (4)

706, 2003, castrch, coolant....

As cheap as factory heads are, grab a 862 used for $150 and slap it in. Change the oil, back in business and no fear.

csxfbird

iTrader: (5)

Well, good and bad news. No evidence of a crack anywhere...but I do indeed have Castech 706 heads.

Now to start the hunt for a set of 862s.

Or do I pull the 241s off the TA and give it a heads/cam swap...?

Darth_V8r

iTrader: (4)

241 flows the same as 706 but worse compression. You would do better to look at prc 5.3 stage 2 or similar

Che70velle

iTrader: (6)

Same here. I have researched this and found that it is because of the “clean side” and “dirty side” of the pvc setup.

G Atsma

Well that just makes total sense. Being that air is pulled from one side of the engine to the other, "input" side being cleaner...

RB04Av

Yup... pass side gets clean air coming in from the filter, driver's side is where dirty air is extracted by the PCV valve/orifice into the intake.

I've lived through the Castech crack issue, and I don't see it in your photos. You're still lucky at this moment.