Accrdwgnguy

So I picked up a 2006 4.8L from a guy on craigslist. He said it had 110k miles, always mobil 1, etc. Just has a blown headgasket. Ok so opened it up the other day and the rocker arms are missing! Great just what I need. So emailed the guy back and he said "My mistake, I'll send you the rocker arms". Fine but from what I read the valve lash is factory set, so what do I do with a jumbled box of rocker arms?

Also, this is what the inside of this thing looks like, can I flush the block assembled? I really did not want to get into the block.

Accrdwgnguy

Ok, did a bit of reading and searching, it appears the pushrod length is what sets the valve lash, so when I get my box of rockers and put them in torque to spec, I should be good. Yes? I hope so, I just about lost my mind when I pulled the valve cover and found them missing, took me a few days to chill out.

96capricemgr

iTrader: (1)

Not that you are out of the woods but that is what I would expect to find with a blown head gasket.

01 Vert ws6

iTrader: (18)

I think you should be more worried about the anti freeze that went threw the motor then the rocker arms . Look at the valve cover that's oil and anti freeze . If that's on the valve covers then what to the rod and main bearings look like

Paul Bell

iTrader: (9)

What are you gonna use this engine for?

Accrdwgnguy

Using this engine in my 86 C10. Pulling both heads and oil pan tomorrow to assess the condition. Not sure I believe his claim of always Mobil 1 oil every 5k miles based on the dark staining. Fearing the worse since he did pull it from a van to replace with another engine.

Paul Bell

iTrader: (9)

If the crank isn't damaged, I suggest you buy bearings, rings and one of those ball hone brush things. Yank it apart, clean it up, hone the cylinders and it'll be good as new. Have a shop freshen up them heads. New oil pump & timing chain. You'll need head & main bolts.

rennat_2006

iTrader: (10)

I bet it has cracked "castech" heads not a blown head gasket.

RockinWs6

I was thinking the same thing.

Accrdwgnguy

Ya know, the guy mentioned specifically in his ad that it did not have castech heads. How do I verify this? Code on the head is 862

EDIT: Went back out and checked over the head closely, no Castech logo. I think I might be in the clear.

rennat_2006

iTrader: (10)

Nope not safe. Heads on my wifes old tahoe did not have castech logos and were cracked.

Need to look down around the head bolt bosses and see if there are little pools of coolant. Might be kind of difficult since you dont know if your engine has been put on its side or anything.

Paul Bell

iTrader: (9)

Good point. You'll need to pull the rocker rail to find the casting logo. In the "problem areas", you'll need to look for minute cracks but it'll need to be pretty clean to see them.

redtan

iTrader: (5)

You bought an engine with a known blown headgasket and you just planned on running it as is without getting into it?

Accrdwgnguy

Do dealerships/auto repair shops fully rebuild engines with a blown headgasket?

Anyways I pulled the head off, cleaned around the bolt holes and can't see any cracks. No castech logo. I'll blow it apart and have it pressure tested.

Root2812

iTrader: (1)

Did you find out if this is the case. I ask because I took my rockers off the other day and although I kept them in order I am concerned after reading your post. (I'm rebuilding my engine). Also what are these "castech" heads and why are they so bad?

Accrdwgnguy

I did a bit of searching on this board, seems the factory installs different length pushrods to set valve lash. I would keep all components of the valvetrain in order to avoid any possible issue.

squalor

iTrader: (3)

Castech did not make 862 heads. It was the 706 diecast heads that had the problem and only some of those. Most 243 heads are made by Castech.

I bought a S10 a few years back with the 2.2L (terrible engine) that had a blown head gasket. I replaced the head and gasket, used new bolts but left the bottom alone. It made it another 15 months before I spun a bearing. If I knew then what I know now.... I would take Paul Bell's advice if I was you.

rennat_2006

iTrader: (10)

Seen two sets or 862 that were cracked exactly as the castech ones do. One set was on my wifes old 02 tahoe and one set is on the engine i pulled out of a 2002 burban that i replaced with a 6.0l due to leak and mileage.

Paul Bell

iTrader: (9)

The Castech heads are prone to cracking around the head bolt holes. Symptoms are coolant oozing from around the bolt heads and coolant in the valve covers/oil pan.

kj598bbc

I'm thinking the intent was that You DON'T buy an engine with a blown head gasket without knowing you're going in it at last heads removed deep. Anyway if the 4.8 was cheap hone, bearings, gaskets gets my vote, with a few upgrades of course.