Fishinfooleric10@aol.com

Well I hope I don't have to but I just got the same symptom that i got when the head gasket blew on my old motor. I replaced the motor in my 99 silverado 5.3 with a 5.3 out of 04. I had to do this because the head gasket blew and put water into oil and ultimately blew it up.

My symptoms just like last time my low coolant light message came up and it doesn't leak externally. This is the first time it has done since I put it in their this past Christmas. I really hope it's not but I am preparing myself for the worst in this case.

So, if I have to do this I got a few questions that hopefully yall can answer. I know i gotta take off alternator, exhaust manifolds, intake and intake manifold and what not but my big question is taking the heads off. I know take out the bolts holding the head in but do I have to take valves out or anything or do I just unbolt the head and then do head gasket. Once I have cleaned and put new head gasket on and go to put heads back on is there anything in particular I need to do or can I just put em back on and bolt down. I have never gone into a motor like this before and would really appreciate it if someone could give me steps on how to do this.

I believe I am capable of doin the job, but I just want to make sure I don't get in over my head or ruin my motor by making a mistake.

Thanks to all for help

MDTAHOE

Be careful it maybe the heads them self.




Bulletin No.: 06-06-01-019B

Date: June 12, 2007

INFORMATION

Subject:
Information on Gradual Coolant Loss Over Time With No Evidence of Leak Found
Models:
2004-2006 Buick Rainier
2001-2006 Cadillac Escalade Models
2001-2006 Chevrolet Avalanche, Blazer, Silverado, Suburban, Tahoe, TrailBlazer Models
2001-2006 GMC Envoy, Jimmy, Sierra, Yukon Models
2001-2004 Oldsmobile Bravada
2005-2006 Saab 9-7X
with 4.8L or 5.3L VORTEC(R) GEN III, GEN IV V8 Engine (VINs V, T, M, B, Z - RPOs LR4, LM7, LH6, L33, L59)

Supercede:

This bulletin is being revised to include engine RPO L59. Please discard Corporate Bulletin Number 06-06-01-019A (Section 06 - Engine/Propulsion System).

Some vehicles may experience a gradual coolant loss over time. A very low percentage of cylinder head(s) manufactured with an embossed Castech logo may develop a porosity crack in a very specific area.

Inspect the cylinder head assembly to determine if the casting was manufactured by Castech. This can be accomplished by inspecting for their casting logo located on top of the intake port, under the rocker arm support rail and in the spring deck cavity portion of the cylinder head.

If the cylinder head(s) are Not a Castech casting, follow normal diagnostic procedures in SI to determine the cause of the coolant loss.




Refer to the illustrations on how to identify Castech casting and/or the very specific areas of the cylinder head(s) for a coolant leak from porosity.

Cylinder head(s) location of the Castech manufacturing casting logo (1).




Close up view of the cylinder head(s) showing the Castech manufacturing casting logo (1).




If the cylinder head(s) is a Castech casting (1), inspect the area around the five oil drain holes for witness marks indicating coolant seepage over time (2).

If No evidence of coolant loss is found on inspection of Castech casting cylinder head(s), follow normal diagnostic procedures in SI to determine the cause of the coolant loss.


The crack location can be found in any of the five cylinder head(s) oil drains. This can be seen as a clean or shiny area, on an otherwise stained surface (1). Pressurizing the cooling system at this time may reveal coolant, air, or a combination, weeping in the described area. If inspection reveals evidence of coolant witness marks (1), replace the entire cylinder head(s) assembly.

Fishinfooleric10@aol.com

Alright MD tahoe I'll look into that and thank you. Anyone else have any help?

Fishinfooleric10@aol.com

If I decide to change the heads completely what yall think about the heads from autozone. I believe they are called sunfire or something like that. Also if someone could answer my above question about the heads.