Need4Camaro

iTrader: (1)

The first 5.3L was probably an 03 model, had less than 1,500 miles (one thousand five hundred) and I had a mechanic put the motor together. He used LS6 Headgaskets but basically, after he put it together, I got the car home and found it leaking coolant right under the driver side header toward the front of the motor, also had white smoke. I didn't drive it afterward but I got the car to another shop and he ends up leaving the motor out in the rain, causing it to rust over so he buys me a new motor, and has the heads machined. I get it to another shop and they reassemble everything with a brand new 0 mile shortblock and my heads with 1,500 miles on it, and even this reputable shop gives it back to me this time with coolant going out the exhaust AND into the oil.

Both the shortblock and the heads were machined and I even have the number to the shops who did it.

What could be causing this to happen? I heard something about header bolts but would that allow coolant to go into the cylendars, and oil?

brandon6.0

iTrader: (32)

Cracked head? Are they the same heads from the first motor? Are they reusing original head bolts? They are torque to yield and not reusable.

Rob WS6

iTrader: (16)

Not sure LS6 head gaskets would be the right ones to use, as the 5.3 has a smaller bore than a 5.7... 96mm vs 99mm would be a 3mm difference which is a lot.

conan

iTrader: (5)

What was done to the heads and the block "machining" wise. Was the block decked ? Were the heads milled ?

Paul Bell

iTrader: (9)

The gaskets were the first thing to raise my suspicions.

The bolts used are a good question.

brandon6.0

iTrader: (32)

Can u use ls6 gaskets on a 5.3? Im thinkin they are for a way bigger bore than a 5.3.

brandon6.0

iTrader: (32)

Op might be best to install standard size headgaskets with correct bolts. I have used thecheap procomp head studs off ebay with good results. Just be careful and easy torqueing them down with correct arp thread sealant for a perfect torque. Jmo! Done once and done!

Burken01

iTrader: (88)

Isn't ideal but its not his problem..

Plenty of guys using ls9 head gaskets which are a 4.100 bore on 5.7, 5.3 and even 4.8 engines in FI apps..

JakeFusion

iTrader: (7)

ARP bolts go in with ARP Ultra Torque Moly Lube on the threads and under the washers in a three pass sequence... 30, 50, and 70-75. They do not go in dry.

LS6 gaskets are fine for the 5.3. You want your gasket bigger than the bore and combustion chamber. Smaller would cause issue.

Paul Bell

iTrader: (9)

OK Jake, I took that out, now I see threads also for the ARP stuff. I always thought it would crack the block. GM bolts have a dry sealer on them and as they're TTY, should not have lube on them.

I'm a stud guy.....

JakeFusion

iTrader: (7)

That's why you have to chase the threads and clean that sumbitch out good. I flipped my block over, took out the drain plugs, and ended up with oil and coolant everywhere. Sucker was bone dry. I took the ARP thread chaser to it, and it was rock n roll time.

01ssreda4

iTrader: (96)

I think there is something wrong with the heads. They are the common denominator between it all.

Burken01

iTrader: (88)

Maybe he was torquing head bolts and compressed some coolant and popped the passage...

And he had to torque that bolt to 40-50 for it to bite afterwards..

I've seen that happen

Need4Camaro

iTrader: (1)

Okay. To clear things up a bit. The block has been decked and the heads have also been machined prior to their second installation and failure. I don't have much knowledge to how the shop torqued the heads down, I know they used the headbolts that came with the headgasket kit but the kit didn't come with header bolts so they used some from a hardware store.

I'm ganna try and tackle this myself since my previous shops aren't able to do it right but I have never done any kind of head work before.

I'm on a budget...

What headbolts should I use?
Is it mandatory that I have an air compressor to do this job?
Do you have any other suggestions I should follow in order to undertake this job?

1FastBrick

iTrader: (16)

You need to inspect the head gasket sealing surface. If the heads you're using are early heads they could have a notch in them.

If there is a notch in them you must use a composite gasket and not an MLS gasket.

You can't guess on the year, you have to check the casting date codes.

If the parts are miss matched from different years then you need to use the right gasket for the heads and the correct bolts for the block.

See this post for pictures http://www.performancetrucks.net/for...8/#post5036600

If there 706 heads they may have a crack. Research Castaech heads for info on that. they typically leak at the casting near the head bolt holes.

01ssreda4

iTrader: (96)

That's correct, a traditional (cheap) head gasket is much more forgiving then an MLS as an FYI.

FIRECHICKEN5.3

I believe factory head gaskets for the 5.3 are MLS. Can't really do much better. You have to put them on dry!! Feel pro directly states NOT to put anything on a MLS gasket not even copper spray.

elizaharry

Use LS6 Head gaskets.

Need4Camaro

iTrader: (1)

Thanks for that information, I need to confirm that I understand though. This notch you're speaking of is on the bottom half (the bottom head) of that image you showed me in the truckforums right? Would it be possible to detect that without removing the head? Also will I also have to remove the head to find the casting number?

nm2769

iTrader: (1)

Notched type heads with MLS gaskets will leak. Image borrowed www.performancetrucks.net I think with an inspection mirror and a good light you should be able to see the notch with the heads on the motor.